Natural Slate Roof Tiles Minimum Pitch

Traditionally natural slate roofs were not recommended below 20 pitch.

Natural slate roof tiles minimum pitch.

Installing natural slate is a more specialist job than most other kinds of roof covering. Roof pitch 40 roof area m 2 150 length of roof slope m 9 5 the headlap can be found from table 1 by reference to slate size roof pitch and exposure 65 mm. The slate coverage per m2 can be found from table 2 23 9. 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 total weight of slates on roof can be found from the formula. 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. However our technical team always believed that it would be possible to specify natural slates with confidence at lower than 20 if the circumstances were right. 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.

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. The roof pitch should be at least 20 which is influenced by the length head lap and thickness of the slate. What is the minimum pitch for natural slate. 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.

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. The general recommendation for the minimum pitch for natural slate is 25. The minimum recommended pitch of a natural slate roof is a function of the exposure level of the site location. Weighing only 800 grams and measuring 300 x 336mm each barrington slate tile resembles high quality stone and is capable of supporting over 120kg in weight making it safe to walk on and easy to handle.

All tiles and slates have a minimum roof pitch which is set out in order to protect the roof from water penetration. 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. There are some manufacturers that can go slightly lower such as the siga 56m natural slate which can go down to 20 in some instances if used with slate hook systems. The minimum recommended pitch for natural slate is 25 although this can be lowered down to 20 with products like the siga 56m natural slate and is also dependent on slate size.