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.
Minimum roof deck slope for the installation of clay tile.
Asphalt shingles continue to be the most widely installed roof covering option in north america.
The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
Ratios from that minimum up to 4 12 which are considered low pitch require double underlayment.
About minimum slope allowed for clay tile roofs or other tile roofs if you read through standards such as icc es esr2015 concrete and clay roof tile installation manual for moderate climates copy on file you ll see that there is no prohibition of clay tiles on low slope roofs.
This article series explains clay tile roofing types clay roofing tile inspection tile roofing diagnosis tile roof repair.
Concrete is long lasting with a minimum lifespan of 50 years depending on climate.
Of the roof deck and additional slope has been provided to.
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.
The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
Over roof edges design and installation of roof drainage sys tems shall comply with section 1503 and the florida building.
This means for every 12 horizontal units the roof must rise a minimum of two and one half vertical units.
Refer to manufacturer s installation instructions frsa tri florida high wind concrete and clay roof tile installation manual fifth edition where the v asd is determined in accordance with section r301 2 1 3 or ras 118 119 or 120 for underlayment and slope requirements for specific roof tile systems.
Clay and concrete roof tiles can only be installed on roof slopes of 2 1 2 12 or greater.
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.
Clay tiles are colorfast which means their tints improve rather than fade over time.
The irc recommends a minimum pitch of 2 5 12 for these materials.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
