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HomeMy WebLinkAboutBLOOM FILING FOUR - FDP240001 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT CTL|Thompson, Inc. Denver, Fort Collins, Colorado Springs, Glenwood Springs, Pueblo, Summit County – Colorado Cheyenne, Wyoming and Bozeman, Montana Multi-Family Residential Buildings 2, 3, and 10 Bloom Filing 4 Apartments Fort Collins, Colorado Prepared for: Hartford Acquisitions 4801 Goodman Street Timnath, Colorado 80547 Attention: Dave Derbes Director of Multi-Family Development Project No. FC07733.016-120 January 24, 2024 SOIL AND FOUNDATION INVESTIGATION Table of Contents Scope 1 Summary Of Conclusions 1 Site Description 2 Proposed Construction 2 Previous Investigations 2 Investigation 3 Subsurface Conditions 3 Native Soils 3 Groundwater 4 Geologic Hazards 4 Site Development 5 Fill Placement 5 Excavations 6 Foundations 6 Footings 7 Reinforced Concrete Mat 7 Post-Tensioned Slab-On-Grade (PT) 8 Floor Systems and Slab-On-Grade Floors 10 Slab Performance Risk 10 Structurally Supported Floors 12 Porches, Decks and Patios 13 Exterior Flatwork 14 Below-Grade Walls 14 Backfill Compaction 15 Subsurface Drainage 16 Pavements 16 Pavement Selection 17 Subgrade and Pavement Materials and Construction 17 Pavement Maintenance 18 Concrete 18 Excavations 19 Construction Observations 20 Geotechnical Risk 20 Limitations 20 APPENDIX A – RESULTS OF LABORATORY TESTS Table A-I – Summary of Laboratory Testing APPENDIX B – PAVEMENT CONSTRUCTION RECOMMENDATIONS APPENDIX C – PAVEMENT MAINTENANCE PROGRAM EXHIBIT A – SLAB PERFORMANCE RISK EVALUATION, INSTALLATION AND MAINTENANCE EXHIBIT B – SURFACE DRAINAGE, IRRIGATION AND MAINTENANCE EXHIBIT C – EXAMPLE BACKFILL COMPACTION ALTERNATIVES FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS FIGURE 2 – SUMMARY LOGS OF EXPLORATORY BORINGS HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 1 Scope This report presents the results of our Soils and Foundation Investigation for proposed apartment buildings 2, 3, and 10, located in the 4th Filing of the Bloom Subdivision in Fort Collins, Colorado (Figure 1). The purpose of our investigation was to evaluate the subsurface conditions to provide geotechnical design and construction recommendations for the proposed structures. The scope was described in our Service Agreement (Proposal No. FC-23-0430) dated November 29, 2023. This report was prepared from data developed during field exploration, laboratory testing, engineering analysis, and experience with similar conditions. It includes our opinions and recommendations for design criteria and construction details for foundations and floor systems, slabs-on-grade, lateral earth loads, and drainage precautions. The report was prepared for the exclusive use of Hartford Acquisitions in design and construction of multi-family residences in the referenced subdivision. Other types of construction may require revision of this report and the recommended design criteria. A brief summary of our conclusions and recommendations follows. Detailed design criteria are presented within the report. Summary Of Conclusions 1. Soils encountered in our borings generally consisted of sandy clay or clayey sand and clean to slightly clayey, gravelly sand to the depths explored. Bedrock was not encountered during this investigation. The soils were non-expansive to low swelling. 2. Groundwater was measured at depths ranging from 9 to 14 feet in six borings during drilling. When measured several days later, groundwater was encountered at depths of 8½ to 14 feet in five borings. Existing groundwater levels are not expected to significantly affect site development. We recommend a minimum 3- foot separation between foundation elements and groundwater. 3. The presence of expansive soils constitutes a geologic hazard. There is risk that slabs-on-grade and foundations will heave or settle and be damaged. We judge the risk is low. We believe the recommendations presented in this report will help to control risk of damage; they will not eliminate that risk. Slabs-on-grade and, in some instances, foundations may be damaged. 4. Footing, post-tensioned slab (PT slab), or reinforced concrete mat foundations, placed on natural, undisturbed soil and/or properly compacted fill are considered appropriate for this site. Design and construction criteria for footing, post-tensioned (PT) slab, and mat foundations are presented in the report. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 2 5. The risk of poor slab performance is rated low for the lots included. A slab-on- grade floor can be used. Driveways and other exterior flatwork will be slabs-on- grade and may heave or settle and crack. 6. Surface drainage should be designed, constructed, and maintained to provide rapid removal of surface runoff away from the proposed structures. Conservative irrigation practices should be followed to avoid excessive wetting. 7. The design and construction criteria for foundations and floor system alternatives in this report were compiled with the expectation that all other recommendations presented related to surface and subsurface drainage, landscaping irrigation, backfill compaction, etc. will be incorporated into the project and that owners will maintain the structures, use prudent irrigation practices, and maintain surface drainage. It is critical that all recommendations in this report are followed. Site Description The proposed construction site is located between International Boulevard and Donella Drive, west of Greenfields Drive in the Bloom Subdivision 4th Filing in Fort Collins, Colorado (Figure 1). During the time of our investigation, overlot grading was complete. Utilities had not yet been installed and the roads were not paved. The site is relatively flat. The Lake Canal runs on the south side of the site. The Burlington Northern Railroad runs northeast of the site. Proposed Construction The three apartment buildings included in this investigation are part of a multi-family residential development comprised of eleven, 3 to 4-story structures, a clubhouse, and pool. Asphalt paved parking areas and access drives are also planned. The proposed structures are anticipated to be wood or steel framed and may have partial brick or stone veneer on the exterior. No basement level or crawlspace construction is planned. The 4-story units will have elevator service pits that extend 4 to 5 feet below grade. Foundation loads are expected to vary between 1,000 and 3,000 pounds per lineal foot of foundation wall, with individual column loads of 25 kips or less. We believe that minimal site grading will be needed for this area and that excavations will take place at or near current grade. Previous Investigations CTL|Thompson has performed several geotechnical investigations at this site under CTL|T Project No. FC07733. Data from the previous investigations were considered for this report. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 3 Investigation The field investigation included drilling two borings for each structure and one boring in one of the parking areas. The borings were drilled to depths of approximately 10 feet and 30 feet using 4-inch diameter continuous-flight augers, and a truck-mounted drill. Drilling was observed by our field representative who logged the soils. Summary logs of the borings, including results of field penetration resistance tests, are presented on Figure 2. Soil samples obtained during drilling were returned to our laboratory and visually examined by our geotechnical engineer. Laboratory testing was assigned and included moisture content, dry density, swell-consolidation, particle-size analysis, Atterberg limits, and water-soluble sulfate tests. Swell-consolidation test samples were wetted at a confining pressure which approximated the weight of overlying soils (overburden pressures). Results of the laboratory tests are presented in Appendix A and summarized in Table A-I. Subsurface Conditions Soils encountered in our borings generally consisted of 10 to 30 feet of sandy clay or clayey sand and clean to slightly clayey, gravelly sand. Bedrock was not encountered during this investigation. The pertinent engineering characteristics of the soil encountered are described in more detail in the following paragraphs. Further descriptions of the subsurface conditions are presented on our boring logs and in our laboratory test results. Native Soils The native soils are comprised of interlayers of sandy clay and clayey sand and clean to slightly clayey, gravelly sand. The granular materials were loose to very dense and the clays were stiff to very stiff according to standard penetration test results. Samples contained 10 to 72 percent silt and clay-size particles (passing the No. 200 sieve). Atterberg limit testing of one sample of clay indicated a liquid index of 42 and a plastic index of 25. Samples of the clay tested for swell- consolidation exhibited swells of nil to 1.4 percent. The granular materials are considered non- expansive or low-swelling based on the results of laboratory testing and our experience. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 4 Groundwater Groundwater was encountered at depths of 9 to 14 feet in six borings during drilling. When measured several days later, groundwater was at depths of 8½ to 14 feet in five borings. Groundwater levels are expected to fluctuate seasonally. Groundwater may develop on or near low permeable soil or bedrock when a source of water not presently contributing becomes available. Groundwater is not expected to affect the proposed construction. Geologic Hazards Colorado is a challenging location to practice geotechnical engineering. The climate is relatively dry, and the near-surface soils are typically dry and relatively stiff. These soils and related sedimentary bedrock formations tend to react to changes in moisture conditions. Some of the soils and bedrock swell as they increase in moisture and are called expansive soils. Other soils can settle significantly upon wetting and are referred to as collapsing soils. Most of the land available for development east of the Front Range is underlain by expansive clay or claystone bedrock near the surface. The soils that exhibit collapse are more likely west of the continental divide; however, both types of soils occur all over the state. Covering the ground with houses, streets, driveways, patios, etc., coupled with lawn irrigation and changing drainage patterns, leads to an increase in subsurface moisture conditions. As a result, some soil movement is inevitable. It is critical that all recommendations in this report are followed to increase the chances that the foundations and slabs-on-grade will perform satisfactorily. After construction, homeowners must assume responsibility for maintaining the structure and use appropriate practices regarding drainage and landscaping. Expansive soils are present at this site. The presence of expansive soils and bedrock, collectively referred to as expansive or swelling soils, constitutes a geologic hazard. There is risk that ground heave or settlement will damage slabs-on-grade and foundations. The risks associated with swelling and compressible soils can be mitigated, but not eliminated by careful design, construction and maintenance procedures. We believe the recommendations in this report will help control risk of foundation and/or slab damage; they will not eliminate that risk. The builder and homebuyers should understand that slabs-on-grade and, in some instances, foundations may be affected. Homeowner HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 5 maintenance will be required to control risk. We recommend the builder provide a booklet to the homebuyers that describes swelling soils and includes recommendations for care and maintenance of homes constructed on expansive soils. Colorado Geological Survey Special Publication 431 was designed to provide this information. Site Development Fill Placement The existing on-site soils are generally suitable for re-use as new fill from a geotechnical standpoint, provided debris or deleterious organic materials are removed. In general, import fill should meet or exceed the engineering qualities of the onsite soils. In addition, particles larger than 3 inches should be broken down or removed. If import material is used, it should be tested and evaluated for approval by CTL|Thompson. Prior to fill placement, debris, organics/vegetation, and deleterious materials should be substantially removed from areas to receive fill. The surface should be scarified to a depth of at least 8 inches, moisture conditioned and compacted to the criteria below. Subsequent fill should be placed in thin (8 inches or less) loose lifts, moisture conditioned, and compacted. Fill should be compacted to a dry density of at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). Fill depths greater than 15 feet should be evaluated by CTL|T to recommend appropriate compaction specifications. Sand soils used as fill should be moistened to within 2 percent of optimum moisture content. Clay soils should be moistened between optimum and 3 percent above optimum moisture content. The fill should be moisture-conditioned, placed in thin, loose lifts (8 inches or less) and compacted as described above. Fill placement and compaction should not be conducted when fill material is frozen. Soft soils were found in one of our borings. If stabilization is necessary, it can likely be achieved by crowding 1½ to 3-inch nominal size crushed rock into the subsoils until the base of the excavation does not deform by more than about 1-inch when compactive effort is applied. CTL|Thompson should observe placement and compaction of fill during construction. Site grading in areas of landscaping where no future improvements are planned can be placed at a dry density of at least 90 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). 1“A Guide to Swelling Soils for Colorado Homebuyers and Homeowners,” Second Edition Revised and Updated by David C. Noe, Colorado Geological Survey, Department of Natural Resources, Denver, Colorado, 2007. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 6 Water and sewer lines are often constructed beneath areas where improvements are planned. Compaction of trench backfill can have a significant effect on the life and serviceability overlying structures. We recommend trench backfill be moisture conditioned and compacted as described above. Placement and compaction of backfill should be observed and tested by a representative of our firm during construction. Excavations We believe the soil penetrated in our exploratory borings can generally be excavated with conventional, heavy-duty excavation equipment. Excavations should be sloped or shored to meet local, State, and Federal safety regulations. Excavation slopes specified by OSHA are dependent upon types of soil and groundwater conditions encountered. The contractor’s “competent person” is responsible to identify the soils and/or rock encountered in excavations and refer to OSHA standards to determine appropriate slopes and safety measures. Based on our investigation and OSHA standards, we believe the interlayered sandy clay and clayey sand soils may classify as Type C soils. Excavations deeper than 20 feet should be braced, or a professional engineer should design the slopes. Wind and water erosion is more likely with disturbed conditions expected during construction and may need to be addressed due to municipal regulation. The erosion potential will decrease after construction if proper grading practices, surface drainage design and re- vegetation efforts are implemented. Foundations Our investigation indicates predominantly low-swelling soils exist at depths likely to affect foundation performance. Footing, reinforced concrete mat or post-tensioned slab foundations are considered appropriate for the proposed construction. Design criteria for footing, mat, and post- tensioned (PT) slab foundations developed from analysis of field and laboratory data and our experience are presented below. The builder and structural engineer should also consider design and construction details established by the structural warrantor (if any) that may impose additional design and installation requirements. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 7 Footings 1. The footing foundation should bear on natural, undisturbed soils and/or on properly compacted fill. Where soils are loosened during excavation or in the footing forming process the soils should be removed or compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99) between optimum and 3 percent above optimum moisture content, prior to placing concrete. Excavation backfill placed below foundations should be compacted using the same specifications. 2. Footings should be designed for a net allowable soil pressure of 2,000 pounds per square foot (psf). The soil pressure can be increased 33 percent for transient loads such as wind or seismic loads. We recommend a minimum 3-foot separation between foundation elements and groundwater. 3. We anticipate footings designed using the soil pressure recommended above could experience 1-inch of movement. Differential movement of ½-inch should be considered in the design. 4. Footings should have a minimum width of 12 inches. Foundations for isolated columns should have minimum dimensions of 16 inches by 16 inches. Larger sizes may be required depending upon the loads and structural system used. 5. Foundation walls should be well reinforced both top and bottom. We recommend reinforcement sufficient to span an unsupported distance of at least 10 feet or the distance between pads whichever is greater. Reinforcement should be designed by the structural engineer considering the effects of large openings and lateral loads on wall performance. 6. Exterior footings must be protected from frost action per local building codes. Normally, 30 inches of cover over footings is assumed in the area for frost protection. 7. The completed foundation excavations should be observed by a representative of our firm prior to placing the forms to verify subsurface conditions are as anticipated from our borings. Our representative should also observe the placement and test compaction of new fill placed for foundation subgrade (if merited). Reinforced Concrete Mat 1. Reinforced concrete mat foundations should be constructed on natural, undisturbed soil and/or properly compacted fill or fill placed for an over-excavation as described in the Site Development section of this report. The reinforced concrete mat foundation should be designed for a net allowable soil pressure of 2,000 psf. The soil pressure can be increased 33 percent for transient loads such as wind or seismic loads. 2. Reinforced slabs are typically designed using a modulus of subgrade reaction. We recommend use of a modulus of 75 pounds per square inch per inch of deflection (pci). HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 8 3. The soils beneath mat foundations can be assigned an ultimate coefficient of friction of 0.4 to resist lateral loads. The ability of foundation backfill to resist lateral loads can be calculated using a passive equivalent fluid pressure of 250 pcf. This assumes the backfill is densely compacted and will not be removed. Backfill should be placed and compacted to the criteria in the Fill Placement section of the report. A moist unit weight of 120 pcf can be assumed for natural soils and compacted fill. These values are considered ultimate values and appropriate factors of safety should be used. Typically, a factor of safety of 1.5 is used for sliding and 1.6 for lateral earth pressure. 4. The edges of the mats should be thickened or turned down for structural strength and frost protection. 5. Materials beneath the mat foundation should be protected from frost action. We believe 30 inches of frost cover is appropriate for this site. 6. We should be retained to observe the completed excavations to confirm whether the subsurface conditions are similar to those found in our borings. Post-Tensioned Slab-On-Grade (PT) PT foundation design is based on a method developed by the Post-Tensioning Institute (PTI) and is outlined in PTI’s third edition of Design of Post-Tensioned Slabs-On-Ground (2004 with 2008 Supplement). Various climate and relevant soil factors are required to evaluate the PTI design criteria. These include Thornthwaite Moisture Index (Im), suction compression index (γh), unsaturated diffusion coefficient (α), depth of probable moisture variation, initial and final soil suction profiles, and percent clay fraction and predominant clay mineral. In the project area, Im is about -20. The PT foundation design method is based on the potential differential movement of the slab edges (ym) over a specified edge distance (em). Further, the PTI design method, evaluates two mechanisms of soil movement (edge lift and center lift) based on assumptions that wetting and drying of the foundation soils are primarily affected by seasonal climate changes. In the 2004 design manual, PTI recommends evaluating movements for a minimum depth of wetting of 9 feet below the ground surface. This value can be reasonable for a seasonal moisture variation; however, our experience indicates the foundation soils will normally undergo an increase in moisture due to covering the ground surface with buildings and flatwork, coupled with the introduction of landscape irrigation around the buildings. Based on our experience and the subsurface conditions at the site, the depth of wetting can be about 24 feet or more below the ground surface. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 9 The wetting may not penetrate this deep; however, we believe it is a reasonable design assumption when evaluating the edge lift for this site. For the deeper depths of wetting, ground movements can be estimated based on swell or suction profiles, or using a computer program (such as “VOLFLO” by Geostructural Tool Kit, Inc.). The PTI design method does not predict soil movement caused by site conditions such as excessive irrigation or poor surface drainage that may lead to differential foundation movement in excess of the movements estimated by the PTI design method. These conditions may also increase the edge moisture variation distance above the design values provided in the PTI manual. Considering the limitations of the current PTI design method, we believe a conservative approach with reasonable engineering judgement is merited in PT foundation design. Design criteria for PT foundations are presented below. Criteria were developed from analysis of field and laboratory data, the PT design method outlined in PTI’s third edition of Design and Construction of Post-Tensioned Slabs-On-Ground (2004 with 2008 Supplement), VOLFLO by Geostructural Tool Kit, Inc., and our experience. 1. PT foundations should be constructed on new moisture-conditioned and compacted fill or directly on native soils. If fill/backfill or soft/loose soils or relatively dry soils are exposed in footing excavations or are the result of the excavation/forming process, these soils should be removed and recompacted. 2. PT foundations should be designed for a maximum allowable soil pressure of 2,000 psf. 3. For design of uniform thickness PT foundations or point loads, a modulus of subgrade reaction (Ks) of 75 pci can be used. 4. A differential soil movement (ym) of 1.13 inches for the edge lift condition and -0.85 inches for the center lift condition can be used. 5. An edge moisture variation distance (em) of 4.8 feet for the edge lift condition and 9 feet for the center lift condition can be used. 6. The above-grade construction, such as framing, drywall, brick, and stucco should be considered when determining the appropriate slab stiffness. We are aware of situations where minor differential slab movement has caused distress to finish materials. One way to enhance performance would be to place reinforcing steel in the bottoms of stiffening beams. The structural engineer should evaluate the merits of this approach, as well as other potential alternatives to reduce damage to finish materials. The slab stiffness should be evaluated per section 6.10 of the PTI 2008 Supplement as it relates to different superstructure materials. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 10 7. Stiffening beams and edge beams may be poured “neat” into excavated trenches. Soil may cave or slough during trench excavation for the stiffening beams. Disturbed soil should be removed from trench bottoms prior to placement of concrete. Formwork or other methods may be required for proper stiffening beam installation. 8. Exterior stiffening beams should be protected from frost action. Normally 2½ feet of frost cover is assumed in the area. If exterior patios are incorporated into the PT, we believe the stiffening beams around the patios should be as deep as those around the building exterior to increase the likelihood they will perform similarly to the rest of the PT. 9. For slab tensioning design, a coefficient of friction value of 0.75 or 1.0 can be assumed for slabs on polyethylene sheeting or a sand layer, respectively. A coefficient of friction of 2.0 should be used for slabs on clay soils. We believe use of polyethylene is preferable because it serves as a vapor retarder which helps to control moisture migration up through the slabs. 10. A representative of our firm should observe the completed excavations. A representative of the structural engineer or our firm should observe the placement of the reinforcing tendons and any mild reinforcement prior to pouring the slabs and beams, and observe the tendon stressing. Floor Systems and Slab-On-Grade Floors Slab Performance Risk We conducted swell-consolidation testing to provide a basis for calculating potential soil heave at this site. We estimate potential heave of 1-inch or less for the structures included. Based on our heave calculations, the subsurface conditions found in our borings, and our experience with residential construction and performance, we judge that the risk of poor slab-on-grade performance at this site is low. Our experience indicates that slab performance is generally satisfactory on low risk sites. Slab heave of 1 to 2 inches is considered “normal” for these sites; more or less heave can occur. If floor movements cannot be tolerated, a structurally supported floor system should be considered. A more detailed discussion of slab-on-grade performance risk and construction recommendations is provided in Exhibit A. If the owner elects to use slab-on-grade construction and accepts the risk of movement and associated damage, we recommend the following precautions for slab-on-grade construction at this site. These precautions can help reduce, but not eliminate, damage or distress due to slab movement. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 11 1. Slabs should be separated from exterior walls and interior load bearing members with a slip joint that allows free vertical movement of the slabs. This can reduce cracking if some movement of the slab occurs. 2. We understand that thickened, interior load bearing slabs may be desired for this site. We believe this to be acceptable, for the units included in this investigation, provided the risk of movement of up to 1-inch is acceptable to the owner. To reduce the risk of movement we recommend saw cutting at the thickened edge for isolation (see image below). 3. Slabs should be placed directly on properly moisture conditioned, well-compacted fill. The 2021 International Building Code (IBC) requires a vapor retarder between the base course or subgrade soils and the concrete slab-on-grade floor, including PT slabs. The merits of installation of a vapor retarder below floor slabs depend on the sensitivity of floor coverings and building use to moisture. A properly installed vapor retarder (10 mil minimum) is more beneficial below concrete slab-on-grade floors where floor coverings, painted floor surfaces or products stored on the floor will be sensitive to moisture. The vapor retarder is most effective when concrete is placed directly on top of it, rather than placing a sand or gravel leveling course between the vapor retarder and the floor slab. The placement of concrete on the vapor retarder may increase the risk of shrinkage cracking and curling. Use of concrete with reduced shrinkage characteristics including minimized water content, maximized coarse aggregate content, and reasonably low slump will reduce the risk of shrinkage cracking and curling. Considerations and recommendations for the installation of vapor retarders below concrete slabs are outlined in Section 5.2.3.2 of the 2018 report of American Concrete Institute (ACI) Committee 302, “Guide for Concrete Floor and Slab Construction (ACI 302.1R-15)”. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 12 4. Use of slab-bearing partitions should be minimized. If used, they should be designed and constructed with a minimum 1½-inch space to allow for slab movement. Differential slab movements may cause cracking of partition walls. Differential movement of ½-inch should be considered in the design. If the void is provided at the top of partitions, the connection between the slab-supported partition and foundation-supported walls should be detailed to allow differential movement. Doorways, in-wall utility connections, wall partitions perpendicular to the exterior wall or walls supported by foundations should be detailed to allow for vertical movement. Interior perimeter framing and finishing should not extend onto slabs-on-grade, or if necessary, should be detailed to allow for movement. 5. Underslab plumbing should be eliminated where feasible. Where such plumbing is unavoidable it should be thoroughly pressure tested for leaks prior to slab construction and be provided with flexible couplings. Pressurized water supply lines should be brought above the floors as quickly as possible. 6. Plumbing and utilities that pass through the slabs should be isolated from the slabs and constructed with flexible couplings. Utilities, as well as electrical and mechanical equipment should be constructed with sufficient flexibility to allow for movement. 7. HVAC or other mechanical systems supported by the slabs (if any) should be provided with flexible connections capable of withstanding at least 3 inches of movement. 8. The American Concrete Institute (ACI) recommends frequent control joints in slabs to reduce problems associated with shrinkage cracking and curling. To reduce curling, the concrete mix should have a high aggregate content and a low slump. If desired, a shrinkage compensating admixture could be added to the concrete to reduce the risk of shrinkage cracking. We can perform a mix design or assist the design team in selecting a pre-existing mix. Structurally Supported Floors Structural floors should be used if floor movement and cracking are unacceptable. A structural floor is supported by the foundation system. There are design and construction issues associated with structural floors that must be considered, such as ventilation and lateral loads. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 13 Where structurally supported floors are installed, the required air space depends on the materials used to construct the floor and the expansion potential of the underlying soils. Building codes require a clear space of 18 inches above exposed earth if untreated wood floor components are used. Where other floor support materials are used, a minimum clear space of 8 inches should be maintained. This minimum clear space should be maintained between any point on the underside of the floor system (including beams and floor drain traps) and the surface of the exposed earth. Where structurally supported floors are used, utility connections, including water, gas, air duct and exhaust stack connections to floor supported appliances, should be capable of absorbing some deflection of the floor. Plumbing that passes through the floor should ideally be hung from the underside of the structural floor and not lain on the bottom of the excavation. This configuration may not be achievable for some parts of the installation. It is prudent to maintain the minimum clear space below all plumbing lines. If trenching below the lines is necessary, we recommend sloping these trenches so they discharge to the foundation drains. Control of humidity in crawlspaces is important for indoor air quality and performance of wood floor systems. We believe the best current practices to control humidity involve the use of a vapor retarder (10-mil minimum), placed on the exposed soils below accessible sub-floor areas. The vapor retarder should be sealed at joints and attached to concrete foundation elements. If desired, we can provide designs for ventilation systems that can be installed in association with a vapor retarder, to improve control of humidity in crawlspace areas. The Moisture Management Task Force of Metro Denver2 has compiled additional discussion and recommendations regarding best practices for the control of humidity in below-grade, under-floor spaces. Porches, Decks, and Patios Porches or decks with overhanging roofs that are integral with the structure such that excessive foundation movement cannot be tolerated, should be constructed with the same foundation type as the building. Simple decks, that are not integral with the structure and can tolerate foundation movement, can be constructed with less substantial foundations. A short pier or footing bottomed at least 3 feet below grade can be used if movement is acceptable. Use of 2 “Guidelines for Design and Construction of New Homes with Below-Grade Under-Floor Spaces,” Moisture Management Task Force, October 30, 2003. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 14 8-foot to 10-foot piers can reduce potential movement. Footings or short piers should not be bottomed in wall backfill or undocumented fill due to risk of settlement. The inner edge of the deck may be constructed on haunches or steel angles bolted to the foundation walls and detailed such that movement of the deck foundation will not cause distress to the structures. We suggest use of adjustable bracket-type connections or other details between foundations and deck posts so the posts can be trimmed or adjusted if movement occurs. Porches, patio slabs, and other exterior flatwork should be isolated from the structures. Porch slabs can be constructed to reduce the likelihood that settlement or heave will affect the slabs. One approach is to place loose backfill under a structurally supported slab. This fill will more likely settle than swell, and can thus accommodate some heave of the underlying soils. A lower risk approach is to construct the porch slab over void-forming materials. Conditions should allow the void-forming materials to soften quickly after construction to reduce the risk of transmitting ground heave to the porch slab. Wax or plastic-coated void boxes should not be used unless provisions are made to allow water to penetrate into the boxes. Exterior Flatwork Exterior flatwork (driveways, sidewalks, etc.) are normally constructed as slabs-on-grade. Various properties of the soils and environmental conditions influence magnitude of movement and other performance. Increases in the moisture content in these soils will cause heaving and may result in cracking of slabs-on-grade. Backfill below slabs should be moisture conditioned and compacted to reduce settlement, as discussed in Backfill Compaction. Exterior slabs founded on the backfill may settle and crack if the backfill is not properly moisture treated and compacted. Where slabs-on-grade are used, we recommend adherence to the precautions for slab-on-grade construction that are included in Exhibit A. Below-Grade Walls Foundation walls, elevator pits, and grade beams that extend below grade should be designed for lateral earth pressures where backfill is not present to about the same extent on both sides of the wall. Many factors affect the value of the design lateral earth pressure. These factors include, but are not limited to, the type, compaction, slope and drainage of the backfill, and the rigidity of the wall against rotation and deflection. For a very rigid wall where negligible or very HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 15 little deflection will occur, an "at-rest" lateral earth pressure should be used in design. For walls that can deflect or rotate 0.5 to 1 percent of the wall height (depending upon the backfill types), lower "active" lateral earth pressures are appropriate. Our experience indicates walls can deflect or rotate slightly under normal design loads and that this deflection results in satisfactory wall performance. Thus, the earth pressure on the walls will likely be between the "active" and "at - rest" conditions. If on-site soils are used as backfill and the backfill is not saturated, we recommend design of walls at this site using an equivalent fluid density of at least 50 pounds per cubic foot (pcf). This value assumes deflection; some minor cracking of walls may occur. If very little wall deflection is desired, higher design density may be appropriate. The structural engineer should also consider site-specific grade restrictions and the effects of large openings on the behavior of the walls. Backfill Compaction Settlement of foundation wall and utility trench backfill can cause damage to concrete flatwork and/or result in poor drainage conditions. Compaction of backfill can reduce settlement. Attempts to compact backfill near foundations to a high degree can damage foundation walls and may increase lateral pressures on the foundation walls. The potential for cracking of a foundation wall can vary widely based on many factors including the degree of compaction achieved, the weight and type of compaction equipment utilized, the structural design of the wall, the strength of the concrete at the time of backfill compaction, and the presence of temporary or permanent bracing. Proper moisture conditioning of backfill is as important as compaction because settlement commonly occurs in response to wetting. The addition of water complicates the backfill process, especially during cold weather. Frozen soils are not considered suitable for use as backfill because excessive settlement can result when the frozen materials thaw. Exhibit C describes four alternative methods to place, moisture condition, and compact backfill along with a range of possible settlements, and advantages and disadvantages of each approach, all based upon our experience. These are just a few of the possible techniques, and represent a range for your evaluation. We recommend Alternatives C or D if you wish to control potential settlement. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 16 Precautions should be taken when backfilling against a wall. Temporary bracing of comparatively long, straight sections of foundation walls should be used to limit damage to walls during the compaction process. Waiting at least seven days after the walls are placed to allow the concrete to gain strength can also reduce the risk of damage. Compaction of fill placed beneath and next to counterforts, and grade beams may be difficult to achieve without damaging these building elements. Proper moisture conditioning of the fill prior to placement in these areas will help reduce potential settlement. Ideally, drainage swales should not be located over the backfill zone (including excavation ramps), as this can increase the amount of water infiltration into the backfill and cause excessive settlement. Swales should be designed to be a minimum of at least 5 feet from the foundation to help reduce water infiltration. Irrigated vegetation, sump pump discharge pipes, sprinkler valve boxes, and roof downspout terminations should also be at least 5 feet from the foundation. Subsurface Drainage No below grade areas are planned for the buildings. For this condition, perimeter drains are not usually constructed. If any portion of a floor will be below exterior grade, or if a crawl space is planned, we should be contacted to provide recommendations for foundation drains. Proper design, construction, and maintenance of surface drainage are critical to the satisfactory performance of foundations, slabs-on-grade, and other improvements. Landscaping and irrigation practices will also affect performance. Exhibit B contains our recommendations for surface drainage, irrigation, and maintenance. Pavements The project will include paved parking areas and access drives. The performance of pavements is dependent upon the characteristics of the subgrade soil, traffic loading and frequency, climatic conditions, drainage, and pavement materials. We used samples from our exploratory borings and conducted laboratory tests to characterize the subgrade soils, which generally consisted of sandy clay and clayey sand. The insitu subgrade soils generally classified as A-7-6 soils in accordance with AASHTO procedures. The subgrade soil will likely provide poor to fair support for new pavement. If fill is needed, we have assumed it will be soils with similar or better characteristics. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 17 Flexible hot mix asphalt (HMA) over aggregate base course (ABC) is likely planned for interior pavement areas. Rigid Portland cement concrete (PCC) pavement should be used for trash enclosure areas and where the pavement will be subjected to frequent turning of heavy vehicles. Our designs are based on the AASHTO design method and our experience. Using the criteria discussed above we recommend the minimum pavement sections provided in the following table. MINIMUM PAVEMENT SECTIONS Classification Hot Mix Asphalt (HMA) + Aggregate Base Course (ABC) Portland Cement Concrete (PCC) Parking Area 4" HMA + 6" ABC 5" PCC Access Drives / Heavy Traffic Areas 5" HMA + 6" ABC 6" PCC Trash Enclosures - 6" PCC Pavement Selection Composite HMA/ABC pavement over a compacted subgrade is expected to perform well at this site based on the recommendations provided. HMA provides a stiff, stable pavement to withstand heavy loading and will provide a good fatigue resistant pavement. However, HMA does not perform well when subjected to point loads in areas where heavy trucks turn and maneuver at slow speeds. PCC pavement is expected to perform well in this area; PCC pavement has better performance in freeze-thaw conditions and should require less long-term maintenance than HMA pavement. The PCC pavement for trash enclosures should extend out to areas where trash trucks park to lift and empty dumpsters. Subgrade and Pavement Materials and Construction The design of a pavement system is as much a function of the quality of the paving materials and construction as the support characteristics of the subgrade. The construction materials are assumed to possess sufficient quality as reflected by the strength factors used in our design calculations. Moisture treatment criteria and additional criteria for materials and construction requirements are presented in Appendix B. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 18 Pavement Maintenance Routine maintenance, such as sealing and repair of cracks, is necessary to achieve the long-term life of a pavement system. We recommend a preventive maintenance program be developed and followed for all pavement systems to assure the design life can be realized. Choosing to defer maintenance usually results in accelerated deterioration leading to higher future maintenance costs, and/or repair. A recommended maintenance program is outlined in Appendix C. Excavation of completed pavement for utility construction or repair can destroy the integrity of the pavement and result in a severe decrease in serviceability. To restore the pavement top original serviceability, careful backfill compaction before repaving is necessary. Concrete Concrete in contact with soil can be subject to sulfate attack. We measured water-soluble sulfate concentrations in four samples at or below 0.04 percent. As indicated in our tests and ACI 332-20, the sulfate exposure class is Not Applicable or RS0. SULFATE EXPOSURE CLASSES PER ACI 332-20 Exposure Classes Water-Soluble Sulfate (SO4) in Soil A (%) Not Applicable RS0 < 0.10 Moderate RS1 0.10 to 0.20 Severe RS2 0.20 to 2.00 Very Severe RS3 > 2.00 A) Percent sulfate by mass in soil determined by ASTM C1580 For this level of sulfate concentration, ACI 332-20 Code Requirements for Residential Concrete indicates there are no cement type requirements for sulfate resistance as indicated in the table below. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 19 CONCRETE DESIGN REQUIREMENTS FOR SULFATE EXPOSURE PER ACI 332-20 Exposure Class Maximum Water/ Cement Ratio Minimum Compressive Strength A (psi) Cementitious Material Types B Calcium Chloride Admixtures ASTM C150/ C150M ASTM C595/ C595M ASTM C1157/ C1157M RS0 N/A 2500 No Type Restrictions No Type Restrictions No Type Restrictions No Restrictions RS1 0.50 2500 II Type with (MS) Designation MS No Restrictions RS2 0.45 3000 V C Type with (HS) Designation HS Not Permitted RS3 0.45 3000 V + Pozzolan or Slag Cement D Type with (HS) Designation plus Pozzolan or Slag Cement E HS + Pozzolan or Slag Cement E Not Permitted A) Concrete compressive strength specified shall be based on 28-day tests per ASTM C39/C39M B) Alternate combinations of cementitious materials of those listed in ACI 332 -20 Table 5.4.2 shall be permitted when tested for sulfate resistance meeting the criteria in section 5.5. C) Other available types of cement such as Type III or Type I are permitted in Exposure Classes RS1 or RS2 if the C3A contents are less than 8 or 5 percent, respectively. D) The amount of the specific source of pozzolan or slag to be used shall not be less than the amount that has been determined by service record to improve sulfate resistance when used in concrete containing Type V cement. Alternatively, the amount of the specific source of the pozzolan or slab to be used shall not be less than the amount tested in accordance with ASTM C1012/C1012M and meeting the criteria in section 5.5.1 of ACI 332-20. E) Water-soluble chloride ion content that is contributed from the ingredients including water aggregates, cementitious materials, and admixtures shall be determined on the concrete mixture ASTM C1218/C1218M between 29 and 42 days. Superficial damage may occur to the exposed surfaces of highly permeable concrete, even though sulfate levels are relatively low. To control this risk and to resist freeze-thaw deterioration, the water-to-cementitious materials ratio should not exceed 0.50 for concrete in contact with soils that are likely to stay moist due to surface drainage or high-water tables. Concrete should have a total air content of 6 percent ± 1.5 percent. We advocate damp-proofing of all foundation walls and grade beams in contact with the subsoils (including the inside and outside faces of garage and crawl space grade beams). Excavations Excavations made at this site, including those for foundations and utilities, may be governed by local, state, or federal guidelines or regulations. Subcontractors should be familiar with these regulations and take whatever precautions they deem necessary to comply with the requirements and thereby protect the safety of their employees and that of the general public. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 20 Construction Observations We recommend that CTL|Thompson, Inc. provide construction observation services to allow us the opportunity to verify whether soil conditions are consistent with those found during this investigation. Other observations are recommended to review general conformance with design plans. If others perform these observations, they must accept responsibility to judge whether the recommendations in this report remain appropriate. Geotechnical Risk The concept of risk is an important aspect with any geotechnical evaluation primarily because the methods used to develop geotechnical recommendations do not comprise an exact science. We never have complete knowledge of subsurface conditions. Our analysis must be tempered with engineering judgment and experience. Therefore, the recommendations presented in any geotechnical evaluation should not be considered risk-free. Our recommendations represent our judgment of those measures that are necessary to increase the chances that the structures will perform satisfactorily. It is critical that all recommendations in this report are followed during construction. Homeowners must assume responsibility for maintaining the structures and use appropriate practices regarding drainage and landscaping. Improvements performed by homeowners after construction, such as construction of additions, retaining walls, decks, patios, landscaping, and exterior flatwork, should be completed in accordance with recommendations in this report. Limitations This report has been prepared for the exclusive use of Hartford Acquisitions for the purpose of providing geotechnical design and construction criteria for the proposed project. The information, conclusions, and recommendations presented herein are based upon consideration of many factors including, but not limited to, the type of structures proposed, the geologic setting, and the subsurface conditions encountered. The conclusions and recommendations contained in the report are not valid for use by others. Standards of practice evolve in the area of geotechnical engineering. The recommendations provided are appropriate for about three years. If the proposed structures are not constructed within about three years, we should be contacted to determine if we should update this report. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 21 Seven borings were drilled during this investigation to obtain a reasonably accurate picture of the subsurface conditions. Variations in the subsurface conditions not indicated by our borings are possible. A representative of our firm should observe foundation excavations to confirm the exposed materials are as anticipated from our borings. We believe this investigation was conducted with that level of skill and care ordinarily used by geotechnical engineers practicing in this area at this time. No warranty, express or implied, is made. If we can be of further service in discussing the contents of this report or in the analysis of the influence of subsurface conditions on design of the structures, please call. CTLTHOMPSON, INC. Trace Krausse, PE R.B. “Chip” Leadbetter, III, PE Geotechnical Project Manager Senior Engineer LEGEND: INDICATES APPROXIMATE LOCATION OF EXPLORATORY BORING INDICATES BUILDING NUMBER GIVEN TO US BY THE CLIENT TH-1 1 TI M B E R L I N E R D . I- 2 5 E. MULBERRY ST. E. VINE DR. SITE FIGURE 1 Locations of Exploratory Borings 0 125'62.5' APPROXIMATE SCALE: 1"=125' VICINITY MAP FORT COLLINS, COLORADO NOT TO SCALE TH-1 TH-2 TH-3 TH-4 TH-6 TH-7 TH-5 1 2 1 4 356 8 710 9 11 HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL I T PROJECT NO. FC07733.016-120 4,905 4,910 4,915 4,920 4,925 4,930 4,935 4,940 4,945 4,950 4,905 4,910 4,915 4,920 4,925 4,930 4,935 4,940 4,945 4,950 18/12 50/12 31/12 11/12 WC=12.3DD=118SW=0.5 TH-1 El. 4938.7 8/12 4/12 25/12 5/12 WC=14.8DD=114SW=0.0SS=0.040 WC=4.7-200=10 TH-2 El. 4939.3 20/12 36/12 22/12 15/12 WC=12.2DD=122SW=0.1 WC=24.1DD=103-200=72 TH-3 El. 4942.3 18/12 9/12 8/12 WC=10.3DD=123SW=0.2SS=<0.01 WC=8.9DD=117SW=0.0 WC=18.9DD=104-200=62 TH-4 El. 4945.3 17/12 12/12 28/12 WC=12.7DD=120SW=0.6SS=<0.01 TH-5 El. 4937.1 28/12 43/12 27/12 6/12 WC=8.9DD=126SW=1.4 WC=5.1-200=16 TH-6 El. 4937.5 11/12 12/12 4/12 WC=14.9DD=114SW=0.4SS=<0.01 WC=18.2DD=107LL=42 PI=25-200=71 TH-7 El. 4936.5 DRIVE SAMPLE. THE SYMBOL 18/12 INDICATES 18 BLOWS OF A 140-POUND HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES. EL E V A T I O N - F E E T FIGURE 2 EL E V A T I O N - F E E T WATER LEVEL MEASURED ON DECEMBER 6, 2023. SAND, GRAVELLY, SLIGHTLY CLAYEY, MOIST, LOOSE TO VERY DENSE, BROWN, (SP, SP-SC) 2. 3. CLAY, SANDY, MOIST, STIFF TO VERY STIFF, BROWN (CL) THE BORINGS WERE DRILLED ON DECEMBER 4, 2023 USING 4-INCH DIAMETER CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG. 1. LEGEND: NOTES: SAND, CLAYEY, VERY MOIST TO WET, LOOSE TO MEDIUM DENSE, BROWN (SC) WATER LEVEL MEASURED AT TIME OF DRILLING. BORING ELEVATIONS WERE SURVEYED BY A REPRESENTATIVE OF THE CLIENT. THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS IN THIS REPORT. 4. Summary Logs of Exploratory Borings WC DD SW -200 LL PI SS - - - - - - - INDICATES MOISTURE CONTENT (%). INDICATES DRY DENSITY (PCF). INDICATES SWELL WHEN WETTED UNDER OVERBURDEN PRESSURE (%). INDICATES PASSING NO. 200 SIEVE (%). INDICATES LIQUID LIMIT. INDICATES PLASTICITY INDEX. INDICATES SOLUBLE SULFATE CONTENT (%). GROUNDWATER READING. INDICATES DEPTH WHERE HOLE CAVED PRIOR TO SECONDARY Building 2 Building 3 Building 10 HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL | T PROJECT NO. FC07733.016-120 APPENDIX A RESULTS OF LABORATORY TESTS TABLE A-I – SUMMARY OF LABORATORY TESTING Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=118 PCF From TH - 1 AT 2 FEET MOISTURE CONTENT=12.3 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=114 PCF From TH - 2 AT 4 FEET MOISTURE CONTENT=14.8 % APPLIED PRESSURE - KSF CO M P R E S S I O N % E X P A N S I O N Swell Consolidation FIGURE A-1 CO M P R E S S I O N % E X P A N S I O N -4 -3 -2 -1 0 1 2 3 TNTAONSER CION UNDSNAPXE GINETTTO WRE DUESSUERP 0.1 10 1001.0 0.1 1.0 10 100APPLIED PRESSURE - KSF -4 -3 -2 -1 0 1 2 3 GNTIEWETOTUEDEMENTMOVON HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL | T PROJECT NO. FC07733.016-120 Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=122 PCF From TH - 3 AT 4 FEET MOISTURE CONTENT=12.2 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=123 PCF From TH - 4 AT 2 FEET MOISTURE CONTENT=10.3 % APPLIED PRESSURE - KSF CO M P R E S S I O N % E X P A N S I O N Swell Consolidation FIGURE A-2 CO M P R E S S I O N % E X P A N S I O N -4 -3 -2 -1 0 1 2 3 TNTAONSER CION UNDSNAPXE GINETTTO WRE DUESSUERP 0.1 10 1001.0 0.1 1.0 10 100APPLIED PRESSURE - KSF -4 -3 -2 -1 0 1 2 3 TNSTAONER CION UNDANSPXE GINTETWTORE DUESSUERP HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL | T PROJECT NO. FC07733.016-120 Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=117 PCF From TH - 4 AT 9 FEET MOISTURE CONTENT=8.9 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=120 PCF From TH - 5 AT 2 FEET MOISTURE CONTENT=12.7 % APPLIED PRESSURE - KSF CO M P R E S S I O N % E X P A N S I O N Swell Consolidation FIGURE A-3 CO M P R E S S I O N % E X P A N S I O N -4 -3 -2 -1 0 1 2 3 GNTIETO WUE TDEMENTMOVON 0.1 10 1001.0 0.1 1.0 10 100APPLIED PRESSURE - KSF -4 -3 -2 -1 0 1 2 3 TNSTAONER CION UNDANSXE P GINTETWTORE DUESSURP E HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL | T PROJECT NO. FC07733.016-120 Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=126 PCF From TH - 6 AT 4 FEET MOISTURE CONTENT=8.9 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=114 PCF From TH - 7 AT 2 FEET MOISTURE CONTENT=14.9 % APPLIED PRESSURE - KSF CO M P R E S S I O N % E X P A N S I O N Swell Consolidation FIGURE A-4 CO M P R E S S I O N % E X P A N S I O N -4 -3 -2 -1 0 1 2 3 TNTAONSER CION UNDSNAPXE GINETTTO WRE DUESSUERP 0.1 10 1001.0 0.1 1.0 10 100APPLIED PRESSURE - KSF -4 -3 -2 -1 0 1 2 3 TNSTAONER CION UNDANSPXE GINTETWTORE DUESSUERP HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL | T PROJECT NO. FC07733.016-120 Sample of SAND, SLIGHTLY CLAYEY, GRAVELLY (SP-SC)GRAVEL 33 %SAND 57 % From TH - 2 AT 14 FEET SILT & CLAY 10 %LIQUID LIMIT % PLASTICITY INDEX % Sample of SAND, CLAYEY, GRAVELLY (SC)GRAVEL 22 %SAND 62 % From TH - 6 AT 9 FEET SILT & CLAY 16 %LIQUID LIMIT % PLASTICITY INDEX % FIGURE A-5 Gradation Test Results 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G 0 10 20 30 50 60 70 80 90 100 PE R C E N T R E T A I N E D 40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G PE R C E N T R E T A I N E D 0 10 20 30 40 50 60 70 80 90 100 HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL | T PROJECT NO. FC07733.016-120 Sample of CLAY, SANDY (CL)GRAVEL 2 %SAND 27 % From TH - 7 AT 4 FEET SILT & CLAY 71 %LIQUID LIMIT 42 % PLASTICITY INDEX 25 % Sample of GRAVEL %SAND % From SILT & CLAY %LIQUID LIMIT % PLASTICITY INDEX % FIGURE A-6 Gradation Test Results 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G 0 10 20 30 50 60 70 80 90 100 PE R C E N T R E T A I N E D 40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PE R C E N T P A S S I N G PERCEN T RETAINED 0 10 20 30 40 50 60 70 80 90 100 HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL | T PROJECT NO. FC07733.016-120 PASSING WATER- MOISTURE DRY LIQUID PLASTICITY APPLIED NO. 200 SOLUBLE DEPTH CONTENT DENSITY LIMIT INDEX SWELL*PRESSURE SIEVE SULFATES BORING (FEET)(%)(PCF)(%)(PSF)(%)(%)DESCRIPTION TH-1 2 12.3 118 0.5 500 CLAY, SANDY (CL) TH-2 4 14.8 114 0.0 500 0.04 CLAY, SANDY (CL) TH-2 14 4.7 10 SAND, SLIGHTLY CLAYEY, (SP-SC) TH-3 4 12.2 122 0.1 500 CLAY, SANDY (CL) TH-3 19 24.1 103 72 CLAY, SANDY (CL) TH-4 2 10.3 123 0.2 500 <0.01 CLAY, SANDY (CL) TH-4 9 8.9 117 0.0 1,100 CLAY, SANDY (CL) TH-4 14 18.9 104 62 CLAY, SANDY (CL) TH-5 2 12.7 120 0.6 500 <0.01 CLAY, SANDY (CL) TH-6 4 8.9 126 1.4 500 CLAY, SANDY (CL) TH-6 9 5.1 16 SAND, CLAYEY, GRAVELLY (SC) TH-7 2 14.9 114 0.4 500 <0.01 CLAY, SANDY (CL) TH-7 4 18.2 107 42 25 71 CLAY, SANDY (CL) SWELL TEST RESULTS* TABLE A-I SUMMARY OF LABORATORY TESTING ATTERBERG LIMITS Page 1 of 1 * NEGATIVE VALUE INDICATES COMPRESSION. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL|T PROJECT NO. FC07733.016-120 APPENDIX B PAVEMENT CONSTRUCTION RECOMMENDATIONS B -1 SUBGRADE PREPARATION Moisture Treated Subgrade (MTS) 1. The subgrade should be stripped of organic matter, scarified, moisture treated and compacted to the specifications stated below in Item 2. The compacted subgrade should extend at least 3 feet beyond the edge of the pavement where no edge support, such as curb and gutter, are to be constructed. 2. Sandy and gravelly soils (A-1-a, A-1-b, A-3, A-2-4, A-2-5, A-2-6, A-2-7) should be moisture conditioned near optimum moisture content and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). Clayey soils (A-6, A-7-5, A-7-6) should be moisture conditioned between optimum and 3 percent above optimum moisture content and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). 3. Utility trenches and all subsequently placed fill should be properly compacted and tested prior to paving. As a minimum, fill should be compacted to 95 percent of standard Proctor maximum dry density. 4. Final grading of the subgrade should be carefully controlled so the design cross- slope is maintained and low spots in the subgrade that could trap water are eliminated. 5. Once final subgrade elevation has been compacted and tested to compliance and shaped to the required cross-section, the area should be proof-rolled using a minimum axle load of 18 kips per axle. The proof-roll should be performed while moisture contents of the subgrade are still within the recommended limits. Drying of the subgrade prior to proof-roll or paving should be avoided. 6. Areas that are observed by the Engineer that have soft spots in the subgrade, or where deflection is not uniform of soft or wet subgrade shall be ripped, scarified, dried or wetted as necessary and recompacted to the requirements for the density and moisture. As an alternative, those areas may be sub-excavated and replaced with properly compacted structural backfill. Where extensively soft, yielding subgrade is encountered; we recommend a representative of our office observe the excavation. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL|T PROJECT NO. FC07733.016-120 B -2 PAVEMENT MATERIALS AND CONSTRUCTION Aggregate Base Course (ABC) 1. A Class 5 or 6 Colorado Department of Transportation (CDOT) specified ABC should be used. Reclaimed asphalt pavement (RAP) or reclaimed concrete pavement (RCP) alternative which meets the Class 5 or 6 designation and design R-value/strength coefficient is also acceptable. 2. Bases should have a minimum Hveem stabilometer value of 78, or greater. ABC, RAP, and RCP must be moisture stable. The change in R-value from 300-psi to 100-psi exudation pressure should be 12 points or less. 3. ABC, RAP or RCP bases should be placed in thin lifts not to exceed 6 inches and moisture treated to near optimum moisture content. Bases should be moisture treated to near optimum moisture content, and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). 4. Placement and compaction of ABC, RAP, or RCP should be observed and tested by a representative of our firm. Placement should not commence until the underlying subgrade is properly prepared and tested. Hot Mix Asphalt (HMA) 1. HMA should be composed of a mixture of aggregate, filler, hydrated lime and asphalt cement. Some mixes may require polymer modified asphalt cement, or make use of up to 20 percent reclaimed asphalt pavement (RAP). A job mix design is recommended and periodic checks on the job site should be made to verify compliance with specifications. 2. HMA should be relatively impermeable to moisture and should be designed with crushed aggregates that have a minimum of 80 percent of the aggregate retained on the No. 4 sieve with two mechanically fractured faces. 3. Gradations that approach the maximum density line (within 5 percent between the No. 4 and 50 sieves) should be avoided. A gradation with a nominal maximum size of 1 or 2 inches developed on the fine side of the maximum density line should be used. 4. Total void content, voids in the mineral aggregate (VMA) and voids filled should be considered in the selection of the optimum asphalt cement content. The optimum asphalt content should be selected at a total air void content of approximately 4 percent. The mixture should have a minimum VMA of 14 percent and between 65 percent and 80 percent of voids filled. 5. Asphalt cement should meet the requirements of the Superpave Performance Graded (PG) Binders. The minimum performing asphalt cement should conform to the requirements of the governing agency. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL|T PROJECT NO. FC07733.016-120 B -3 6. Hydrated lime should be added at the rate of 1 percent by dry weight of the aggregate and should be included in the amount passing the No. 200 sieve. Hydrated lime for aggregate pretreatment should conform to the requirements of ASTM C 207, Type N. 7. Paving should be performed on properly prepared, unfrozen surfaces that are free of water, snow, and ice. Paving should only be performed when both air and surface temperatures equal, or exceed, the temperatures specified in Table 401- 3 of the 2023 Colorado Department of Transportation Standard Specifications for Road and Bridge Construction. 8. HMA should not be placed at a temperature lower than 245oF for mixes containing PG 64-22 asphalt, and 290oF for mixes containing polymer-modified asphalt. The breakdown compaction should be completed before the HMA temperature drops 20oF. 9. Wearing surface course shall be Grading S or SX for residential roadway classifications and Grading S for collector, arterial, industrial, and commercial roadway classifications. 10. The minimum/maximum lift thicknesses for Grade SX shall be 1½ inches/2½ inches. The minimum/maximum lift thicknesses for Grade S shall be 2 inches/3½ inches. The minimum/maximum lift thicknesses for Grade SG shall be 3 inches/5 inches. 11. Joints should be staggered. No joints should be placed within wheel paths. 12. HMA should be compacted to between 92 and 96 percent of Maximum Theoretical Density. The surface shall be sealed with a finish roller prior to the mix cooling to 185oF. 13. Placement and compaction of HMA should be observed and tested by a representative of our firm. Placement should not commence until approval of the proof rolling as discussed in the Subgrade Preparation section of this report. Sub-base, base course or initial pavement course shall be placed within 48 hours of approval of the proof rolling. If the Contractor fails to place the sub-base, base course or initial pavement course within 48 hours or the condition of the subgrade changes due to weather or other conditions, proof rolling and correction shall be performed again. Portland Cement Concrete (PCC) 1. Portland cement concrete should consist of Class P of the 2023 CDOT - Standard Specifications for Road and Bridge Construction specifications for normal placement. PCC should have a minimum compressive strength of 4,500 psi at 28 days and a minimum modulus of rupture (flexural strength) of 600 psi. Job mix designs are recommended and periodic checks on the job site should be made to verify compliance with specifications. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL|T PROJECT NO. FC07733.016-120 B -4 Portland cement should be Type II “low alkali” and should conform to ASTM C2. 150. Portland cement concrete should not be placed when the subgrade or air3. temperature is below 40°F. Concrete should not be placed during warm weather if the mixed concrete has a4. temperature of 90°F, or higher. Mixed concrete temperature placed during cold weather should have a5. temperature between 50°F and 90°F. Free water should not be finished into the concrete surface. Atomizing nozzle6. pressure sprayers for applying finishing compounds are recommended whenever the concrete surface becomes difficult to finish. Curing of the Portland cement concrete should be accomplished by the use of a7. curing compound. The curing compound should be applied in accordance with manufacturer recommendations. Curing procedures should be implemented, as necessary, to protect the8. pavement against moisture loss, rapid temperature change, freezing, and mechanical injury. Construction joints, including longitudinal joints and transverse joints, should be9. formed during construction, or sawed after the concrete has begun to set, but prior to uncontrolled cracking. All joints should be properly sealed using a rod back-up and approved epoxy10. sealant. Traffic should not be allowed on the pavement until it has properly cured and11. achieved at least 80 percent of the design strength, with saw joints already cut. Placement of Portland cement concrete should be observed and tested by a12. representative of our firm. Placement should not commence until the subgrade is properly prepared and tested. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL|T PROJECT NO. FC07733.016-120 APPENDIX C PAVEMENT MAINTENANCE PROGRAM C-1 MAINTENANCE RECOMMENDATIONS FOR FLEXIBLE PAVEMENTS A primary cause for deterioration of pavements is oxidative aging resulting in brittle pavements. Tire loads from traffic are necessary to "work" or knead the asphalt concrete to keep it flexible and rejuvenated. Preventive maintenance treatments will typically preserve the original or existing pavement by providing a protective seal or rejuvenating the asphalt binder to extend pavement life. 1. Annual Preventive Maintenance a. Visual pavement evaluations should be performed each spring or fall. b. Reports documenting the progress of distress should be kept current to provide information on effective times to apply preventive maintenance treatments. c. Crack sealing should be performed annually as new cracks appear. 2. 3 to 5 Year Preventive Maintenance a. The owner should budget for a preventive treatment at approximate intervals of 3 to 5 years to reduce oxidative embrittlement problems. b. Typical preventive maintenance treatments include chip seals, fog seals, slurry seals and crack sealing. 3. 5 to 10 Year Corrective Maintenance a. Corrective maintenance may be necessary, as dictated by the pavement condition, to correct rutting, cracking, and structurally failed areas. b. Corrective maintenance may include full depth patching, milling and overlays. c. In order for the pavement to provide a 20-year service life, at least one major corrective overlay should be expected. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL|T PROJECT NO. FC07733.016-120 C-2 MAINTENANCE RECOMMENDATIONS FOR RIGID PAVEMENTS High traffic volumes create pavement rutting and smooth, polished surfaces. Preventive maintenance treatments will typically preserve the original or existing pavement by providing a protective seal and improving skid resistance through a new wearing course. 1. Annual Preventive Maintenance a. Visual pavement evaluations should be performed each spring or fall. b. Reports documenting the progress of distress should be kept current to provide information of effective times to apply preventive maintenance. c. Crack sealing should be performed annually as new cracks appear. 2. 4 to 8 Year Preventive Maintenance a. The owner should budget for a preventive treatment at approximate intervals of 4 to 8 years to reduce joint deterioration. b. Typical preventive maintenance for rigid pavements includes patching, crack sealing and joint cleaning and sealing. c. Where joint sealants are missing or distressed, resealing is mandatory. 3. 15 to 20 Year Corrective Maintenance a. Corrective maintenance for rigid pavements includes patching and slab replacement to correct subgrade failures, edge damage and material failure. b. Asphalt concrete overlays may be required at 15-to-20-year intervals to improve the structural capacity of the pavement. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS - BLDGS. 2, 3, & 10 CTL|T PROJECT NO. FC07733.016-120 HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 EXHIBIT A-1 EXHIBIT A SLAB PERFORMANCE RISK EVALUATION, INSTALLATION AND MAINTENANCE As part of our evaluation of the subsoils and bedrock, samples were tested in the laboratory using a swell test. In the test procedure, a relatively undisturbed sample obtained during drilling is first loaded and then flooded with water and allowed to swell. The pressure applied prior to wetting can approximate the weight of soil above the sample depth or be some standard load. The measured percent swell is not the sole criteria in assessing potential movement of slabs-on-grade and the risk of poor slab performance. The results of a swell test on an individual lot are tempered with data from surrounding lots, depth of tests, depth of excavation, soil profile, and other tests. This judgment has been described by the Colorado Association of Geotechnical Engineers (CAGE, 1996) as it relates to basement slab-on-grade floors. It can also be used to help judge performance risk for other slabs-on-grade such as garage floors, driveways, and sidewalks. CTL Thompson also performs potential heave calculations to aid in our judgment. The risk evaluation is considered when we evaluate appropriate foundation systems for a given site. In general, more conservative foundation designs are used for higher risk sites to control the likelihood of excessive foundation movement. As a result of the Slab Performance Risk Evaluation, sites are categorized as low, moderate, high, or very high risk. This is a judgment of the swelling characteristics of the soils and bedrock likely to influence slab performance. REPRESENTATIVE MEASURED SWELL AND CORRESPONDING SLAB PERFORMANCE RISK CATEGORIES Slab Performance Risk Category Representative Percent Swell* (500 psf Surcharge) Representative Percent Swell* (1000 psf Surcharge) Low 0 to <3 0 to <2 Moderate 3 to <5 2 to <4 High 5 to <8 4 to <6 Very High > 8 > 6 *Note: The representative percent swell values presented are not necessarily measured values; rather, they are a judgment of the swelling characteristics of the soil and bedrock likely to influence slab performance. The rating of slab performance risk on a site as low or high is not absolute. Rather, this rating represents a judgment. Movement of slabs may occur with time in low, moderate, high, and very high-risk areas as the expansive soils respond to increases in moisture content. Overall, the severity and frequency of slab damage usually is greater in high and very high rated areas. Heave of slabs-on-grade of 3 to 5 inches is not uncommon in areas rated as high or very high risk. On low and moderate risk sites, slab heave of 1 to 2 inches is considered normal and we believe in the majority of instances, movements of this magnitude constitute reasonable slab performance; more heave can occur. Slabs can be affected on all sites. On lots rated as high or very high risk, there is more likelihood of need to repair, maintain, or replace basement and garage floors and exterior flatwork. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 EXHIBIT A-2 For portions of the houses where conventional slabs-on-grade are used, we recommend the following precautions. These measures will not keep slabs-on-grade from heaving; they tend to mitigate damages due to slab heave. 1. Slab-on-grade floor construction should be limited to areas such as garages and basements where slab movement and cracking are acceptable to the builder and homebuyer. 2. The 2021 International Residential Code (IRC R506) states that a 4-inch base course layer consisting of clean graded sand, gravel, crushed stone, or crushed blast furnace slag shall be placed beneath below grade floors (unless the underlying soils are free-draining), along with a vapor retarder. Installation of the base course and vapor retarder is not common in this area. Historically, there has been some concern that installation of clean base course could allow wetting of expansive soils to spread from an isolated source. IRC states that the vapor retarder can be omitted where approved by the building official. The merits of installation of a vapor retarder below floor slabs depend on the sensitivity of floor coverings and building use to moisture. A properly installed vapor retarder is more beneficial below concrete slab-on-grade floors where floor coverings, painted floor surfaces, or products stored on the floor will be sensitive to moisture. The vapor retarder is most effective when concrete is placed directly on top of it, rather than placing a sand or gravel leveling course between the vapor retarder and the floor slab. Placement of concrete on the vapor retarder may increase the risk of shrinkage cracking and curling. Use of concrete with reduced shrinkage characteristics including minimized water content, maximized coarse aggregate content, and reasonably low slump will reduce the risk of shrinkage cracking and curling. Considerations and recommendations for the installation of vapor retarders below concrete slabs are outlined in Section 3.2.3 of the 2015 American Concrete Institute (ACI) Committee 302, “Guide for Concrete Floor and Slab Construction (ACI 302.R-96)”. 3. Conventional slabs should be separated from exterior walls and interior bearing members with a slip joint that allows free vertical movement of the slabs. These joints must be maintained by the homebuyer to avoid transfer of movement. 4. Underslab plumbing should be thoroughly pressure tested during construction for leaks and be provided with flexible couplings. Gas and waterlines leading to slab- supported appliances should be constructed with flexibility. The homebuyer must maintain these connections. 5. Use of slab bearing partitions should be minimized. Where such partitions are necessary, a slip joint (or float) allowing at least 2 inches of free vertical slab movement should be used. Doorways should also be designed to allow vertical movement of slabs. To limit damage in the event of movement, sheetrock should not extend to the floor. The homebuyer should monitor partition voids and other connections and re-establish the voids before they close to less than 1/2-inch. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 EXHIBIT A-3 6. Plumbing and utilities that pass through slabs should be isolated from the slabs. Heating and air conditioning systems constructed on slabs should be provided with flexible connections capable of at least 2 inches of vertical movement so slab movement is not transmitted to the ductwork. These connections must be maintained by the homebuyer. 7. Roofs that overhang a patio or porch should be constructed on the same foundation as the structure. Isolated piers or pads may be installed beneath a roof overhang provided the slab is independent of the foundation elements. Patio or porch roof columns may be positioned on the slab, directly above the foundation system, provided the slab is structural and supported by the foundation system. Structural porch or patio slabs should be constructed to reduce the likelihood that settlement or heave will affect the slab by placing loose backfill under the structurally supported slab or constructing the slab over void-forming materials. 8. Patio and porch slabs without roofs and other exterior flatwork should be isolated from the foundation. Movements of slabs should not be transmitted to the foundation. Decks are more flexible and more easily adjusted in the event of movement. 9. Frequent control joints should be provided in conventional slabs-on-grade to reduce problems associated with shrinkage cracking and curling. Panels that are approximately square generally perform better than rectangular areas. We suggest an additional joint about 3 feet away from and parallel to foundation walls. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 EXHIBIT B-1 EXHIBIT B SURFACE DRAINAGE, IRRIGATION AND MAINTENANCE Performance of foundations and concrete flatwork is influenced by the moisture conditions existing within the foundation soils. Surface drainage should be designed to provide rapid runoff of surface water away from proposed residences. Proper surface drainage and irrigation practices can help control the amount of surface water that penetrates to foundation levels and contributes to settlement or heave of soils and bedrock that support foundations and slabs-on-grade. Positive drainage away from the foundation and avoidance of irrigation near the foundation also help to avoid excessive wetting of backfill soils, which can lead to increased backfill settlement and possibly to higher lateral earth pressures, due to increased weight and reduced strength of the backfill. CTL | Thompson, Inc. recommends the following precautions. The homebuyer should maintain surface drainage and, if an irrigation system is installed, it should substantially conform to these recommendations. 1. Wetting or drying of the open foundation excavations should be avoided. 2. Excessive wetting of foundation soils before, during and after construction can cause heave or softening of foundation soils and result in foundation and slab movements. Proper surface drainage around the residence and between lots is critical to control wetting. 3. The ground surface surrounding the exterior of each residence should be sloped to drain away from the building in all directions. We recommend a minimum constructed slope of at least 12 inches in the first 10 feet (10 percent) in landscaped areas around each residence, where practical. The recommended slope is for the soil surface slope, not surface of landscaping rock. 4. We do not view the recommendation to provide a 10 percent slope away from the foundation as an absolute. It is desirable to create this slope where practical because we know that backfill will likely settle to some degree. By starting with sufficient slope, positive drainage can be maintained for most settlement conditions. There are many situations around a residence where a 10 percent slope cannot be achieved practically, such as around patios, at inside foundation corners, and between a house and nearby sidewalk. In these areas, we believe it is desirable to establish as much slope as practical and to avoid irrigation. We believe it is acceptable to use a slope on the order of 5 percent perpendicular to the foundation in these limited areas. 5. For lots graded to direct drainage from the rear yard to the front, it is difficult to achieve 10 percent slope at the high point behind the house. We believe it is acceptable to use a slope of about 6 inches in the first 10 feet (5 percent) at this location. 6. Between houses that are separated by a distance of less than 20 feet, the constructed slope should generally be at least 10 percent to the swale used to convey water out of this area. For lots that are graded to drain to the front and back, we believe it is acceptable to install a slope of 5 to 8 percent at the high point (aka “break point”) between houses. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 EXHIBIT B-2 7. Construction of retaining walls and decks adjacent to the residence should not alter the recommended slopes and surface drainage around the residence. The ground surface under decks should be compacted and slope away from the residence. 10- mil plastic sheeting and landscaping rock may be placed under decks to soil erosion and/or formation of depressions under the deck. The plastic sheeting should direct water away from the residence. Retaining walls should not flatten the surface drainage around the residence or impede surface runoff. 8. Swales used to convey water across yards and between houses should be sloped so that water moves quickly and does not pond for extended periods of time. We suggest minimum slopes of about 2 to 2.5 percent in grassed areas and about 2 percent where landscaping rock or other materials are present. If slopes less than about 2 percent are necessary, concrete-lined channels or plastic pipe should be used. Fence posts, trees, and retaining walls should not impede runoff in the swales. 9. Backfill around the foundation walls should be moistened and compacted. 10. Roof downspouts and drains should discharge well beyond the limits of all backfill. Splash blocks and/or extensions should be provided at all downspouts so water discharges onto the ground beyond the backfill. We generally recommend against burial of downspout discharge. Where it is necessary to bury downspout discharge, solid, rigid pipe should be used and it should slope to an open gravity outlet. Downspout extensions, splash blocks and buried outlets must be maintained by the homeowner. 11. The importance of proper irrigation and drainage practices and maintenance cannot be over-emphasized. Irrigation should be limited to the minimum amount sufficient to maintain vegetation; application of more water will increase likelihood of slab and foundation movements. Landscaping should be carefully designed and maintained to minimize irrigation. Plants placed close to foundations, particularly within 5 feet of the foundation, should be limited to those with low moisture requirements and utilize only sub-surface irrigation such as standard low volume drip emitters or in-line drip irrigation. Irrigated grass, irrigation mainlines, above- surface spray heads, rotors, and other above-surface irrigation spray devices should not be located or discharge above the ground surface within 5 feet of the foundation. 12. Plastic sheeting should not be placed beneath landscaped areas adjacent to foundation walls or grade beams. Geotextile fabric will inhibit weed growth yet still allow natural evaporation to occur. HARTFORD ACQUISITIONS BLOOM FILING 4 APARTMENTS – BLDGS. 2, 3, & 10 CTLT PROJECT NO. FC07733.016-120 EXHIBIT C-1 EXHIBIT C EXAMPLE BACKFILL COMPACTION ALTERNATIVES Alt. Description Possible Settlement Pros (+) / Cons (-) A Place in 18 to 24-inch lifts, without moisture conditioning. Compact lift surface to about 85 percent of maximum standard Proctor (ASTM D698) dry density. 5 to 15 percent of depth (for 8 feet of backfill, 5 to 15 inches) + Fast + Water not required - Excessive Settlement - Highest water penetration - Highest probability of warranty repair B Moisture condition within 2 percent of optimum, place in 12 to 18-inch lifts. Compact lift surface to about 85 to 90 percent. 5 to 10 percent of depth + Relatively Fast - Moderate water penetration - Excessive settlement - Need for water - Warranty repairs probable C Moisture condition to within 2 percent of optimum and place in 8 to 12-inch lifts. Compact lift surface to 90 to 95 percent. 2 to 5 percent of depth + Reduced warranty + Reduced water infiltration + Reduced settlement - Possible higher lateral pressure - Slower - Need for water - Potential damage to walls D Moisture condition and place as in C. Compact lift surface to at least 95 percent 1 to 2 percent of depth + Reduced warranty + Reduced water infiltration + Lowest comparative settlement - Possible higher lateral pressure - Slower - Need for water - Potential damage to walls