Slope Roof Tile Regulations

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.

Slope roof tile regulations.

Ventilation is not required to a warm roof system which is where the insulation is placed above the joists or rafters. The requirements for an asphalt shingles roof are contained in the international building code. California roofing laws cover everything from licensure of the roofing company to the types of shingles that must be used to the slope of the roof. To qualify as a cool roof under the ladwp consumer rebate program the roofing material must have crrc 3 year sri value 75 for low slope 2 12 or 16 for steep slope 2 12 roofs for the enhanced rebate have crrc 3 year sri value 85 for low slope 2 12 or 35 for steep slope 2 12 roofs how to apply.

According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. California roofing codes establish a list of rules that all builders and contractors must adhere to in order to ensure safe building practices within the state. Also if clay and concrete roof tiles are installed on a roof slope of 2 1 2 12 to 4 12 it shall be provided with a double underlayment application. 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.

On slopes less than 3 1 2 12 roofing tile is considered decorative only. For example a roof that rises 3 inches for every 12 inches has a pitch of 3 12. This means for every 12 horizontal units the roof must rise a minimum of two and one half vertical units. The underlying roof provides all the necessary waterproofing.

If the roof is close to a boundary which is often the case the roof should also have properties to limit the risk from fire spreading across the boundary. In general there is no maximum slope for tile roofs. 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. With a pitched roof the type of tile or slate you wish to use will be partly governed by how steep or shallow the slope is.

Not all roofs need to be ventilated. However on extremely steep roofs above 19 12 or on vertical applications wind currents may cause tiles to rattle. 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.