HomeMy WebLinkAboutLot Certifications - 02/06/2020 (5)02.06.2020
February 6, 2020
Mr. Dan Mogen
City of Fort Collins
700 Wood Street
Fort Collins, CO 80521
RE: 637 Smith Street Supplemental Grade Certification Documentation
Lot 3, Block 166, City of Fort Collins
Dear Mr. Mogen,
Northern Engineering has inspected the property at 637 Smith Street to determine suitability of
the asbuilt grading on the site. The project included expansion of an existing home and addition
of an outbuilding/garage at the back alley. The foundation was already installed, and foundation
elevations were not modified with the project. As such, lot lines were not modified substantially
with the construction and the property does not meet slope requirements laid out in the standard
grade certification form. It is our opinion that the grading of the property and additional
measures taken will protect the property from flooding and standing water sufficiently to allow
approval of the grading and storm drainage for certificate of occupancy.
The property grading and drainage design implemented a gravel French drain along each of the
property lines with perforated subdrain to discharge at Smith Street. The builder installed these
perforated drains and exposed them for Northern Engineering to review. The builder has attested
to us that they have installed all buried drains consistent slope between shots that we were able
to obtain.
The gravel is exposed at the ground surface. It is our opinion that the gravel drains and subdrains
will collect stormwater from the landscape areas around the building envelope effectively and
that the downspouts will discharge into the pipe and/or the gravel media sufficiently to carry
surplus runoff away from the home with minimal risk of flooding from these facilities.
Deviations to the standard lot grading certification requirements are noted with supplemental
information provided herewith:
#3 - Elevations noted on the grading plan along sideyards were not met but were mitigated by
installation of French drains.
Page 2
#5 – 5% slope was not achieved due to reuse of existing foundation and grading at lot lines.
Finished grade slope at the foundation was increased where possible and downspouts have been
connected to the French drain system.
#6 – Slopes are flatter than 1% however drainage is directed to the French drain system.
#7 – Builder has asserted that drains have been tied into the French drain appropriately. System
is buried and unable to be verified by Northern Engineering.
Northern Engineering is hereby certifying the drainage within the lot is sufficient to protect the
structure from flooding inundation and standing water. The builder has provided certification of
the acceptability of the design and asbuilt condition from a qualified structural engineer. The
structural engineer is certifying that the asbuilt drainage facilities are sufficient to avoid
foundation damage from runoff and standing water.
Northern Engineering bases this certification of accounts provided by the builder regarding
underground facilities. Builder remains responsible for installation of all facilities and any defects
or irregularities of installation not disclosed to Northern Engineering.
Please let us know if you have any questions or concerns.
Sincerely,
Northern Engineering Services, Inc.
Ryan Banning
Project Manager
Attachments or Enclosures:
Certification of Lot Grading
Grading and Drainage Design Memo by Les Crawford, Site Development Solutions
Structural/Foundation certification by On Site Structural Engineering
STRUCTURAL ENGINEERING
MEMO
February 4, 2020
Mountain Standard Homes
Attn: Sean Carson
scarson@mountainstandardhomes.com
Lafayette, CO 80026
RE: Site Grading at 637 Smith St, Fort Collins, CO 80524
OSS Job#: DAN20153
Dear Sean,
A representative of our office visited the above referenced site on 2/4/20 to observe the final
grading around the perimeter of the project. We observed positive drainage away from the
structure on all sides, as well as gutters and downspouts that are tied directly into property drains
that daylight to the east side of the lot.
Based on our observations and conversations with you regarding the foundation perimeter drain, it
is our opinion that the current site grading should not adversely affect the performance of the
foundation.
Please note that Daniel Belleau, PE, was Engineer of Record for the project during his Tenure at DLK
Engineering, LLC until December 26, 2019.
Please do not hesitate to contact me if you have any questions.
Sincerely,
On Site Structural Engineering, LLC
By: _________________________________
Daniel M Belleau, PE
Principal
970.227.6368
Daniel@ossengr.com