Maximum Pitch For Slate Roof

Tiles or slates can be used at pitches up to 90 degrees vertical provided a clip is available to securely clip the tail of the tile available for most tiles.

Maximum pitch for slate roof. What is the maximum roof pitch for a roof tile. Generally a slate roof is not installed on a pitch less than 4 12. 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 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.

It is agreed that the roof pitch should be a minimum of 20 degrees preferably a bit more. 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. 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.

The slope of a roof is often referred to as the roof s pitch. 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.