A handy roof slope estimator can help you determine if your roof slope is likely too low for shingles.
Roof underlayment requirements for low pitched roof.
In steep slope roofs 4 12 and steeper the upper courses of felt underlayment should overlap lower courses by at least 2 inches.
Asphalt saturated felt along the eaves and lap succeeding courses by 19 inches as shown in figure 2 3.
Felt details for various roof slopes amp.
Roofs at the lower end of the range about 4 12 to 6 12 are relatively easy to walk and work on.
Guide to roofing underlayment installation on low slope roofs with asphalt shingles.
Minimum pitch for corrugated metal roof.
Asphalt shingles can be used on roofs with a slope of 2 12 to 4 12 if double coverage underlayment is used.
Starting at the eave apply 36 inch wide 914.
Anything above that will require you to put out higher cost because they are already considered as higher pitch.
This pitch might be as low as 1 12.
Start with a 19 inch strip of 15 lb.
Think of a classic addams family haunted house with its soaring peaks and you have a.
My roof at lowest is 75 12.
The other side is 2 12.
This article series discusses roofing felt specifically addressing the roofing code or roofing manufacturer s requirements for use of an underlayment such as roofing felt tarpaper or other underlayment products beneath asphalt shingles and other.
In either case find a professional roofing contractor experienced with low slope roofs and these specific products.
Is roofing felt required.
The standard of lower pitch actually ranges between 1 12 to 5 12.
The majority of north american residential roofs have historically been constructed with a slope between about 4 12 and 9 12.
If the roof slope is below 3 12 pitch see our previous post on how to determine a roof s pitch the entire roof should be covered but only if the roof is conventionally vented cold roof construction.
A metal roof mechanically seamed crimped and butyl injected at the seams designed to handle low slopes as low as 5 12.
Roofing underlayment roofing felt requirements.
Roofs on victorian era houses were often sharply angled with a steep pitch.
For roof slopes from two units vertical in 12 units horizontal 17 percent slope up to four units vertical in 12 units horizontal 33 percent slope underlayment shall be two layers applied in the following manner.
As in all construction work paying attention to the little details can make all the difference between a long lasting trouble free project and one that results in callbacks and early failure never a good option with a new england roof.
Apply a 19 inch 483 mm strip of underlayment felt parallel to and starting at the eaves fastened sufficiently to hold in place.
I have found the proper roof but the underlayment options and guidance has been scattered.
I ve been told by many i need a new roof and a particular style at that.
Visually this roof appears flat.
You can see the difference between the underlayment overlapped 19 inches on the roof to the right and overlapped 2 inches on the roof to the left.
