Minimum Pitch For Man Made Slate Roof

Example slate type del carmen slate size mm mm 400 250 weight of slates kg 1000 1235 exposure moderate roof pitch 40 roof area m 2 150 length of roof slope m 9 5 the headlap can be found from table 1 by reference to slate size roof pitch and exposure 65 mm.

Minimum pitch for man made slate roof.

How easy is natural slate to install. Generally a slate roof is not installed on a pitch less than 4 12. But since there is still a wide variety of slate roofing systems there are occasions when the minimum pitch can go down to as low as 15 0 depending on the uniqueness of the roof. Installing natural slate is a more specialist job than most other kinds of roof covering.

As per the nrca roofing and waterproofing manual fifth edition they recommend that roof deck slopes intended for the application of steep slope materials at 4 12 18 degrees or greater. It is agreed that the roof pitch should be a minimum of 20 degrees preferably a bit more. In order to provide you with the opportunity to specify low pitched slate roofs below 20 with confidence siga commissioned the bre to carry out a set of tests. Our suggestion is not to contemplate using slates on roofs with a pitch less than 20 degrees and then only for big format slates eg 500x300mm.

Higher exposure or different sized slates necessitated a greater roof pitch of 22 5 or more. The minimum recommended pitch for natural slate is 25 although this can be lowered down to 20 with products like the siga 56m natural slate and is also dependent on slate size. A couple of likely slate suppliers are consulted and they confirm that they are happy to supply 600x300mm slates for a minimum roof pitch of 20 degrees assuming a minimum lap of 125mm. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs.

Although bs 5534 recommends a minimum pitch of 20 ssq has developed a successful slate roofing system that allows the roof s pitch to be reduced to 17 5 generally and under some circumstances as low as 15 in areas considered to be unexposed. Conventional low pitch slate roofs are recommended down to a minimum of 20 in areas of sheltered or moderate exposure providing a 500x300mm slate is used and a headlap of 115mm. 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. Total weight of slate roof the total weight of slates on a roof can be calculated as follows.

You consider some alternative solutions. Minimum roof pitch for shingles.