Minimum Slope For Tile Roof

The minimum roof slope allowed by code for any type of roofis in 12 applicable only to coal tar pitch roof systems.

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. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. 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. 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.

Clay tiles are colorfast which means their tints improve rather than fade over time. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. In traditional home construction it was not recommended to have a roof pitch lower than 20. However on extremely steep roofs above 19 12 or on vertical applications wind currents may cause tiles to rattle.

Asphalt shingles continue to be the most widely installed roof covering option in north america. 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. Both clay and concrete tile are available in many colors and are naturally weather resistant. The irc recommends a minimum pitch of 2 5 12 for these materials.

This means for every 12 horizontal units the roof must rise a minimum of two and one half vertical units. In general there is no maximum slope for tile roofs. However with modern roofing materials such as boral roofing tiles the minimum roof pitch can be as low as 15. Although the minimum roof pitch for residential homes may vary depending on city and state building codes.

The following tableprovides the minimum required allowable roof slope for each type of roofing material mentioned in the code. Nrca s recommended minimum roof slope guidelines for steep slope roof systems generally are greater at steeper inclines than those in the building code. Concrete is long lasting with a minimum lifespan of 50 years depending on climate.