Slate Roof Pitch Regulations

This means for every 12 horizontal units the roof must rise a minimum of two and one half vertical units.

Slate roof pitch regulations.

Headlap as defined in the national slate association s slate roofs design and installation manual 2010 edition is the length in inches of the upper portion of a roofing slate that is covered by the butt of the slate two course above. 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. You consider some alternative solutions. 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.

Minimum roof slope roof pitch r905 3 2. 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. Where the thickness of natural slates reduces their pitch by 3 or more select the next lower rafter pitch to determine the recommended head lap and slate width. The roof pitch should be at least 20 which is influenced by the length head lap and thickness of the slate.

Minimum fixing on double lap slates. Clay and concrete roof tiles can only be installed on roof slopes of 2 1 2 12 or greater. 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. It is agreed that the roof pitch should be a minimum of 20 degrees preferably a bit more.