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.
Plain roof tiles minimum pitch.
With the introduction of machine made clay tiles this has now dropped slightly to 30 similar to the marley hawkins single camber tile.
90 subject to fixing specification.
It has long been enshrined in our british standards for roofing that the minimum roof pitch for plain tiles is 35 degrees or 40 degrees for handmade clay tiles that do not fall into the geometric tolerances set manufacturing standards.
As a general rule tiles and slates will perform down to the pitches outlined below.
267mm x 165mm.
100mm roof 115mm vertical cover width.
Linear cover of 1 tile.
165 mm covering capacity net 60 tiles m.
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.
Plain tile technical data size.
Below 90 at 90 tile thickness.
It is this long experience in use that tells us what the minimum roof pitch should be and how to achieve the many intricate and interesting roof designs that suit plain tiles.
Florida building code fbc specifies that clay and concrete tile be installed to the standards in the florida roofing and sheet metal association s frsa concrete and clay roof tile installation manual.
65 mm 35 mm.
Sunday july 1 2018.
88 mm minimum gauge.
Interlocking clay plain tiles 15 degrees.
60 tiles m at 100mm gauge roof 53 tiles m at 115mm gauge vertical weight of tiling.
65mm roof 37 5mm vertical maximum gauge.
Previously it was accepted that 35 was the lowest recommended pitch for both concrete and clay variants of the tile.
In most instances 35 will be the minimum pitch for plain concrete tiles which is another reason why the material is the preferred choice for those who use them regularly.
Plain tiles 35 degrees.
Clay pantiles 30 degrees.
Natural slate 25 degrees.
Clay single camber plain tiles can pitch down to 30 manufacturer dependant although the vast majority available have a limit of 35.
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.
For example a roof that rises 3 inches for every 12 inches has a pitch of 3 12.
88 mm maximum gauge.
To calculate roof pitch take the lowest point of the roof and measure the amount of rise for every 12 inches of horizontal movement toward the highest point.
Interlocking concrete and clay tiles 22 5 degrees.
268 x 165 mm minimum pitch.
73 8kg m 0 72 kn m at 100mm gauge roof.
13 mm hanging length.
100 mm 115 mm.
Guidelines for roof sections falling below a 35 pitch.