The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
Minimum slope for gable roof.
An example for a steep sloped roof is 8 12.
This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units.
Asphalt shingles can only be installed on roof slopes of 2 12 or greater.
A gable roof is a traditional triangle shaped roof that can range from a medium pitch to sharp angled roofs.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
This means that the rise of the slope goes up or down 8 inches for every 12 inches.
The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.
Another widely used method is to follow the house s roof pitch on one side building the ridge off center then sloping down more drastically on the shorter side which will be closer to the house.
It is uncommon to find a roof below 15 but for those very low pitch applications there are interlocking clay pantiles available suitable for use down to 12 5.
So if your roof rises 4 inches for every 12 inches of horizontal length then the pitch of your roof is expressed as 4 12.
Normal shingle installation is allowed for all roofs with a pitch of 4 12 and above.
The minimum roof slope for metal roofs is dependent upon the roof profile.
Low sloped roof shingle installation.
Minimum pitch for metal roof.
With regards to metal roofing the profile refers to the shape adopted by the metal sheets when they are bent to form the panels.
Keep in mind that neither metal shingles not corrugated metal panels are suitable options for low slope or nearly flat roofs.
Roof pitch is the measurement of roof steepness.
Asphalt shingles continue to be the most widely installed roof covering option in north america.
Traditionally a minimum roof pitch of 20 was recommended in bs 5534 but modern tiles and slates have now been designed for applications as low as 15.
Asphalt shingles minimum roof slope roof pitch r905 2 2.
The way pitch also known as roof slope is measured is rise over run.
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.
A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible.
Normal roof slope for typical installation.
To put it in perspective the angle of this slope would be around 30 degrees.
This can be a nice look even when it is turned with the gable end to the house and the door is under the short pitch rather than a gable end.