The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
Minimum slope for clay tile roof.
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.
Anything lower than this angle is rare and although there are specific products that can go lower 15 is the most common minimum angle for clay tiles.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
Roof slope requirements for tiled roofs.
The irc recommends a minimum pitch of 2 5 12 for these materials.
Clay and concrete roof tiles can only be installed on roof slopes of 2 1 2 12 or greater.
Clay and concrete tile minimum roof slope roof pitch r905 3 2.
Adapted paraphrased with permission from best practices guide to residential construction chapter on best roofing practices.
Concrete is long lasting with a minimum lifespan of 50 years depending on climate.
Asphalt shingles continue to be the most widely installed roof covering option in north america.
Ratios from that minimum up to 4 12 which are considered low pitch require double underlayment.
Likewise the nails used to attach clay tiles to the decking should be corrosion resistant copper or stainless steel.
Clay tiles are colorfast which means their tints improve rather than fade over time.
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.
Tile covered roof installation specifications.
The general trend is for steeper pitch roofs which is due partly to the demand for living space in the roof.
This means for every 12 horizontal units the roof must rise a minimum of two and one half vertical units.
This article series explains clay tile roofing types clay roofing tile inspection tile roofing diagnosis tile roof repair.
Instead flashing for clay tile must be formed from heavy gauge copper or stainless steel.
Aluminum or galvanized sheet metal sufficient for the life of an average asphalt roof would be the weakest link in a clay tile roof.
For many years 20 was recommended as the minimum pitch for clay tiles but this has decreased in the modern era down to 15.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
