HomeMy WebLinkAbout721 Glenloch Dr - Inspection Results/Addition or Alteration - 04/15/2011City of Fort Collins
Neighborhood & Building Services
281 N. College Avenue
Fort Collins, CO 80524
Re: Permit #61004316
Covered Patio Framing Inspection Comments
721 Glenloch Drive
Dear Sir,
This is in response to the attached residential covered patio inspection comments, Permit #131004316,
for the property located at 721 Glenloch Drive, Fort Collins, CO 80524. The noted deficiency is with
regard to the 4"x4" structural posts that have been mounted to the house exterior wall with (4) 3/8" x
6" lag screws and if this attachment method will provide the required support necessary for the
resultant snow and dead loads that will act upon these posts.
The required snow load and dead load for a residential patio cover is 30 lbs/s.f. and 10 Ibs/s.f.
respectively as noted in the Fort Collins Residential Patio Cover Handout — 2003 IRC. The roof loading
for the north and south patio ends is transferred to the structural post that is attached to the house, the
structural post at the patio cover corner and the ledger at the hip connection. The total roof loading
that is associated with the above noted post that is attached to the house is calculated to be 25 s.f. of
roofing area, this includes the 1' soffit overhang. The total snow and dead load for this post is therefore
1,000 lbs. The side grain withdrawal force for a 3/8" lag screw that is attached to Douglas Fir or
Hemlock Fir studs is conservatively 100 Ibs/in; (withdrawal design value per inch of penetration in
pounds). The 3/8" x 6" lag screws have been recessed into the 4"x4" posts allowing for 2" of
penetration, developing 200 Ibs/lag screw of withdrawal force.
The number of lag screws required to support the associated roof load of 1000 Ibs is therefore (5),
however it is my recommendation that a total of (6) 3/8" x 6" lag screws be installed in each post to
allow for any variations within the wood members and an additional factor of safety.
euriis Ber
6446 S. Robb Way
Littleton, CO 80127
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