Minimum Slope For Clay Tile Roof

This means for every 12 horizontal units the roof must rise a minimum of two and one half vertical units.

Minimum slope for clay tile roof.

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. All tiles have a minimum roof pitch which is always stated in the manufacturers technical information. The irc recommends a minimum pitch of 2 5 12 for these materials.

Concrete is long lasting with a minimum lifespan of 50 years depending on climate. Ratios from that minimum up to 4 12 which are considered low pitch require double underlayment. 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. In that case the underlayment is principally cushioning the underside of the tiles and giving a bit of extra leak insurance.

This minimum pitch is important if tiles are laid below the recommended minimum pitch there is an increased chance of water getting through which can damage the underlay and battens over a prolonged period. 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.