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.

Minimum slope for clay tile roof.

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 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 that case the underlayment is principally cushioning the underside of the tiles and giving a bit of extra leak insurance.

Concrete is long lasting with a minimum lifespan of 50 years depending on climate. 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. 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. Other clay tile roofs such as ours here on the other side of your wall in mexico depend on the clay tiles themselves to collect and shed water off of the roof.

Clay and concrete roof tiles can only be installed on roof slopes of 2 1 2 12 or greater. The irc recommends a minimum pitch of 2 5 12 for these materials.