Generally a slate roof is not installed on a pitch less than 4 12.
Minimum pitch for man made slate roof.
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 page 405.
It is agreed that the roof pitch should be a minimum of 20 degrees preferably a bit more.
Size of the lap.
Guidance on these components can be found in british standard bs 5534 2014 the code of practice for slating and tiling.
Type of slate being used.
While it s a more costly option due to the processes and materials that go into its manufacturing this versatile slate can be used on pitched roofs at 15.
The minimum slope of a roof depends on the roof s profile.
Originally produced in asbestos cement and now for many years in fibre cement these cost effective slates are regularly used in re roofing for all types of buildings.
The general recommendation for the minimum pitch for natural slate is 25.
Size of the slate.
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.
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.
You need to consider the slope requirements of each panel to determine this minimum slope.
The redland cambrian grey slate is a good example of man made slate as it is composed of 60 of natural slate the slate also comes with interlocking ability.
There are some manufacturers that can go slightly lower such as the siga 56m natural slate which can go down to 20 in some instances if used with slate hook systems.
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.
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.
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.
Pitch of the roof.
Improvements in the products aesthetics maintain its regular use.
With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 20 0 for slate roofs.
Higher exposure or different sized slates necessitated a greater roof pitch of 22 5 or more.
The slope of a roof is often referred to as the roof s pitch.
The profile is the shape taken by the sheets when you bend them to form panels.