Headlap Slate Roof

Headlap exposure and offset.

Headlap slate roof.

Most significant is the environment with the two main factors being exposure to wind and rain. Minimum recommended headlap mm unit 15 16 airfield approach business park flookburgh grange over sands cumbria la11 7ng england tel. Headlap is a fundamental necessity on slate roofs that are laid with a shingle style the most common installation method in the. Most stock slates will be pre holed at 75 90 or 100mm allowing you the versatility of different pitches commonly 25 degrees in moderate exposure zones and 30 degrees in severe.

Holing gauge batten gauge headlap 10mm. 4 traditional roofing 2007 joseph jenkins inc. These are all words that should send a chill up the spine of any good slater. Roofs shallower than 4 12 should not be made of slate according to traditional roofing.

Once you have chosen pitch and headlap you ll be able to determine the number of slates you ll need per m 2 using our coverage tables. Notes from bs 5534 2014. There are few details on a slate roof installa. If your property s roof is in the green moderate part of the uk but you know of prevailing bad winds or weather you may wish to use the other chart instead.

There are few details on a slate roof installation that if done wrong will cause the entire roof to be condemned and have to be removed and done all over again. Headlap and exposure are related to each other and the starting point for determining both is roof slope. The minimum roof pitch for natural slates is 20 degrees bs 5534 2014 page 45 depending on size of slate see table above bs 5534 2014 page 45 table 9. If your roof is shallower between 4 12 and 8 12 the slates should have a headlap of at least four inches.

Laying slate with appropriate headlap and offset helps to accommodate wind driven rain and the lateral movement of water below the slate shingles to prevent infiltration through the nail holes and side joints.