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.

The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. 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. Relating to the pitch the building standard code bs 5534 recommends a minimum pitch of 20 deg for slate roofs which can be achieved through specific design although most manufacturers recommend a 25 degree minimum pitch. A greater pitch is likely to make the house look top heavy.

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 answer depends on a number of factors such as height rafter length site location slate or tile being used etc. Higher exposure or different sized slates necessitated a greater roof pitch of 22 5 or more. The min pitch for slating was changed from 22 5 to 25 in 2002.

The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. 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. 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. 2002 irish code of practice for slating and tiling.

In the past slates were thought to be effective at 22 5 degrees and this was set as the minimum acceptable pitch. Each roof has to be assessed individually. This came about due to the revisions in the code of practice icp2. 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.