Minimum Pitch For Slate Roof Ireland

The roof finish manufacturer will specify the minimum and maximum pitch required to ensure weatherproofing.

Minimum pitch for slate roof ireland.

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. 2002 irish code of practice for slating and tiling. Each roof has to be assessed individually. The answer depends on a number of factors such as height rafter length site location slate or tile being used etc.

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 min pitch for slating was changed from 22 5 to 25 in 2002. Higher exposure or different sized slates necessitated a greater roof pitch of 22 5 or more. 11 august 2015 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.

In general terms the minimum pitch is 22 5 degrees but we have seen pitched roofs perform down to 15 degrees pitch. 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. This came about due to the revisions in the code of practice icp2. In the past slates were thought to be effective at 22 5 degrees and this was set as the minimum acceptable pitch.

A greater pitch is likely to make the house look top heavy. 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. Typically roof pitches in ireland are in the 30 to 40 degree range to repel the rain quickly from a slate or tile covering and provide some degree of practical attic space for storage. The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.