They last from 60 to 200 years with their main problems lying in the fastening material which can rust if made from corrosive substances.
Minimum pitch for slate roof tiles.
The minimum pitch for each product can be found in the table below and in the product brochure or within the products pages some tiles and slates incorporate design features allowing them to be laid at a low minimum pitch.
Slate tile requires a pitch of 4 12 or greater.
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.
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.
For a 15 pitch the exposure level of site must be sheltered or.
Minimum pitch for slate roof when considering the minimum pitch for a slated roof it is necessary to establish the exposure of the site the length of rafter and the height of the building.
Confirm the exposure level of the site using our annual driving rain index map.
The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
Steps to specifying a low pitch slate roof.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
The recommendations shown above are based on a maximum height to eave of 12m and a maximum rafter length of 9m in moderate exposure and 6m in severe exposure.
Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater.
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.
Mineral surfaced roll roofing requires a minimum roof pitch of 1 12 or greater.
If you do have a long rafter length extreme local topography or you are working on a tall building we.
All tiles and slates have a minimum roof pitch which is set out in order to protect the roof from water penetration.