The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
Minimum roof pitch for gravel and tar.
Degrees to pitch rise in run table.
Run in degrees and as percentage the minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
Tar gravel roof repair.
2 asphalt and gravel or coal tar and gravel roofs may be constructed with lower slopes than required in sentence 1 when effective drainage is provided by roof drains located at the lowest points on the roofs.
Otherwise the safest minimum pitch for rolled roofing is 2 inches of decline per 12 inches of horizontal direction 2 12 pitch.
Ballast is commonly used with roofs made of tar and gravel roof alternatives.
Asphalt shingles continue to be the most widely installed roof covering option in north america.
How roof pitch determines suitable roofing systems.
3 profiled metal roof cladding systems specifically designed for low slope applications are.
The traditional roof coating system simply do.
If you have a home with a flat roof a tar and gravel roof may be a good option for you.
Roof pitch multiplier table.
1 see sentence 9 26 3 1 2.
The roof was less than 8 years old and was missing a lot of gravel.
Notes to table 9 26 3 1.
I frequently see tar and gravel on flat roofs but rarely on sloped roofs.
Hi all just wondering if anyone knows what the maximum slope is for a built up roof tar and gravel.
Although the primary purpose of ballast is to weigh down the roofing materials it also offers similar protective benefits as described above.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
Tar and gravel roofs sometimes referred to as conventional built up roofing or bur roofs tar and gravel roofing is a system of flat roofing protection that is budget friendly and can have a lifespan of up to 30 years.
Flat and nearly flat roofs a pitch of 1 in 12 or 2 in 12 cannot be covered with shingles or shakes of any material since there is not enough angle to combat the danger of blow off.
Repairing a tar and gravel is of course best left to the professionals and since a properly maintained bur roofing system can last for decades chances are you will have to repair your roofing system at some point during its existence.
Preparing and coating tar and gravel roofs can be extremely difficult with a traditional roof coating approach.
For that reason flat roofs are limited to these types of covering materials.
If your roof pitch declines up to 1 inch vertically for every 12 inches horizontally 1 12 pitch it is a good candidate for rolled roofing as long as you use the concealed nail method of fastening.
Gravel on a ballast roof system.
Roof slope equivalents as rise.
