You consider some alternative solutions.
Minimum angle for slate roof.
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.
When slating with a shallow pitch a wide slate is highly recommended for maximum side lap or lateral lap side overlaps.
Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials.
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.
With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs.
Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio.
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.
Table 1 minimum recommended laps in mm for different exposures and roof pitches moderate exposure index between 3m 2 s and 7m s slate size mm roof pitch length width 85 45 40 35 30 25 221 2 20 600 300 65 65 75 75 90 105 125 500 300 65 65 75 75 90 90 115 500 250 50 65 65 75 75 90 105 120 450 300 50 65 65 75 75 90 100 120.
There is no maximum pitch up to 90 degrees.
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.
Generally speaking 20degrees is the lowest advisable pitch for a slate roof depending on the size of the slates and how much that the roof is exposed to moderate weather conditions.
This means for every 12 horizontal units the roof must rise a minimum of 4 vertical units.
Higher exposure or different sized slates necessitated a greater roof pitch of 22 5 or more.
It is agreed that the roof pitch should be a minimum of 20 degrees preferably a bit more.
Also redland cambrian interlocking slate which is very realistic will go down to 15 degrees.
