Slope For Tile Roof

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

Slope for tile roof.

A 4 12 is a roof slope that rises by 4 inches for every 12 inches across. Express the slope of a metal roof by a ratio which indicates the pitch of the roof. So the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally. It is often compared to slope but is not exactly the same.

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. In general there is no maximum slope for tile roofs. To calculate roof pitch take the lowest point of the roof and measure the amount of rise for every 12 inches of horizontal movement toward the highest point. For example a roof that rises 3 inches for every 12 inches has a pitch of 3 12.

You need to consider the slope requirements of each panel to determine this minimum slope. Shingle roofs typically have a life span of 15 30 years while membrane roofs usually last 5 15 years. This means for every 12 horizontal units the roof must rise a minimum of two and one half vertical units. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run.

Clay and concrete roof tiles can only be installed on roof slopes of 2 1 2 12 or greater. The minimum slope of a roof depends on the roof s profile. This forms an angle of 18 5 between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low pitch and medium pitch roof. 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.

The profile is the shape taken by the sheets when you bend them to form panels. Although ceramic tile roofs are expensive they can have a life span of over 100 years. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. 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.

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.