Minimum Slope For Concrete Tile Roof

The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.

Minimum slope for concrete tile roof.

Boral concrete tiles are manufactured using an extrusion process. In general the minimum slope for a tile roof is 3 12. Asphalt shingles continue to be the most widely installed roof covering option in north america. When the roof angle is less than 30º the windward slope can be subjected to severe suction or negative pressure fig 4.

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. Roofs steeper than 35º generally present sufficient obstruction to the wind for a positive. Fixing tile roofs in cyclonic regions 15 minimum roof pitch 15 maximum rafter lengths 15 maximum rafter lengths no sarking 15. Our wessex and mendip concrete roof tiles can be used down to a minimum 15 pitch.

The underlying roof provides all the necessary waterproofing. 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. In general there is no maximum slope for tile roofs. However on extremely steep roofs above 19 12 or on vertical applications wind currents may cause tiles to rattle.

The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. Concrete is long lasting with a minimum lifespan of 50 years depending on climate. Both clay and concrete tile are available in many colors and are naturally weather resistant. If a customer insists on installing roof tiles on a roof with a pitch below 3 12 consult the tile manufacturer for installation specifications.

The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Clay tiles are colorfast which means their tints improve rather than fade over time. And our brand new mendip 12 5 can be used at an even lower pitch of 12 5 restrictions on rafter length may apply. This means for every 12 horizontal units the roof must rise a minimum of two and one half vertical units.