The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
Roof slope limits for architect 80 shingle.
There are also 29 standard sized shingles measuring 12 inches by 36 inches in each one of these.
This article discusses best roofing practices for the installation of asphalt roof shingles including installation temperature shingle sealing methods shingle course offsets asphalt shingle nailing location and specifications low slope and steep slope limits for asphalt shingles and roof flashing at building eaves and around skylights.
Asphalt shingles can only be used on roof slopes of two units vertical in 12 units horizontal 2 12 or greater.
This project guide is a combination of those two articles and it covers replacing the existing roof decking installing underlayment and ice dam protection laying the first row laying shingles in the field flashing ridge shingles and vents and more.
In areas where icing along eaves can cause the back up of water apply certainteed winterguard waterproofing shingle underlayment or its equivalent according to.
Low sloped roof shingle installation.
A couple of weeks ago we published a two part series showing how a local roofing contractor shingled a roof with architectural shingles.
The roof design is all hip.
Roof length measured in feet roof width measured in feet roof pitch.
Is a 30 degree slope and 7 12 pitch correct for.
If 4 12 and above is normal and 2 12 is minimum what about properties with roofs in between the two such as a 3 12 pitched roof.
Normal shingle installation is allowed for all roofs with a pitch of 4 12 and above.
We do install shingles on these in between pitches but special application measures must be taken in this middle ground.
Installation on roof slopes below a 2 in 12 pitch is not recommended at all.
With that as background you are now ready to estimate how many shingles you will purchase for your roof project.
If a roof slope exceeds this limitation the shingles should be applied by the following recommended method complying with astm d4586.
The maximum slope considered suitable for normal shingle application is 45 degrees or 12 per foot.
What is roof slope and does it limit the choice of shingles.
A 4 12 roof slope means the roof rises 4 feet.
What is the minimum slope for an asphalt shingle roof.
Normal roof slope for typical installation.
For budget conscious homeowners metal shingles will run about 7 to 10 per square foot installed while corrugated metal sheets can be installed for 3 50 to 5 50 per square foot for materials and labor.
Asphalt shingles continue to be the most widely installed roof covering option in north america.
Use on roofs with slopes greater than 2 per foot.
The slope of the roof is measured by the vertical rise of the roof to the horizontal run and is expressed as a fraction.
The asphalt shingle manufactures recommend that you install asphalt shingles on a recommended minimum of 4 in 12 or greater however most manufactures will warrant their shingles down to a 2 in 12 pitch if the recommended installation method is used.
This roof shingle calculator requires four basic inputs.
Low slope applications 2 to 4 per foot require additional underlayment.
