Building Code and Building Construction - Questions and Answers
Or when you want to know how construction is supposed to be done.

|
AskCodeMan.com
|

Custom Search

Minimum roof pitch

Minimum roof pitch

New postby mmarcley on Sun Dec 06, 2009 8:41 am

In building a dormer, I need max height at the low end and therefore need absolute minmum roof pitch. How low can I go?
mmarcley
 
Posts: 3
Joined: Sat Dec 05, 2009 2:06 pm

Re: Minimum roof pitch

New postby Jerry Peck - Codeman on Sun Dec 06, 2009 11:19 pm

Hi Mark,

Depends on the roof covering type.

If shingles, most manufacturers say down to 2-1/2:12 slope with some saying down to 1-1/2:12 slope with special underlayment conditions.

If metal roofing such as standing seam, 5-V crimp or similar styles, most manufacturers say down to 4:12 slope.

If concrete tile or slate, most manufacturers say down to 4:12 slope.

If modified bitumen single ply and other similar roofs, most manufacturers say down to 1/4:12 slope.

Also note that the end of the dormer at the window might not need to meet a 7 foot ceiling headroom.
Jerry Peck - CodeMan
AskCodeMan.com
Construction Litigation Consultant - Retired
Construction and Code Consultant - Semi Retired
User avatar
Jerry Peck - Codeman
Site Admin
 
Posts: 1199
Joined: Fri Dec 12, 2008 12:06 pm


Return to Structure: Footings, foundation walls, floor framing, wall framing, ceiling framing, roof framing (rafters & engineered trusses)



Who is online

Users browsing this forum: No registered users and 2 guests


cron