Minimum Slope For Tile Roof

Sunday july 1 2018 the international residential code irc specifies a minimum 4 12 pitch 4 inches of vertical rise for every 12 inches of horizontal run for a clay or concrete tile roof except that a pitch as low as 2 1 2 12 is allowed when two layers of underlayment are applied.

Minimum slope for tile roof.

Asphalt shingles continue to be the most widely installed roof covering option in north america. Clay tiles are colorfast which means their tints improve rather than fade over time. However with modern roofing materials such as boral roofing tiles the minimum roof pitch can be as low as 15. Nrca s recommended minimum roof slope guidelines for steep slope roof systems generally are greater at steeper inclines than those in the building code.

However on extremely steep roofs above 19 12 or on vertical applications wind currents may cause tiles to rattle. For asphalt shingle clay and concrete tile metal shingle slate and wood shake and shingle roof systems nrca recommends slopes of 4 12 or more. The requirements for an asphalt shingles roof are contained in the international building code. The following tableprovides the minimum required allowable roof slope for each type of roofing material mentioned in the code.

To avoid this use wind clips on each tile along with a construction grade silicone sealant or other approved sealant. The irc recommends a minimum pitch of 2 5 12 for these materials. In traditional home construction it was not recommended to have a roof pitch lower than 20. Minimum roof slope roof pitch r905 3 2 clay and concrete roof tiles can only be installed on roof slopes of 2 1 2 12 or greater.

Concrete is long lasting with a minimum lifespan of 50 years depending on climate. 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. The minimum roof slope allowed by code for any type of roofis in 12 applicable only to coal tar pitch roof systems. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.

Although the minimum roof pitch for residential homes may vary depending on city and state building codes. This means for every 12 horizontal units the roof must rise a minimum of two and one half vertical units. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.