Flat Roof Minimum Pitch Uk

Flat roof drainage.

Flat roof minimum pitch uk.

According to bs 6229 bs 8217 flat roofs should be designed with minimum falls of 1 40 to ensure a finished fall of 1 80 can be achieved allowing for any inaccuracies in the construction. 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. What pitch is a flat roof. To enable compliance with the requirements of the building regulations to be demonstrated full details of the new roof will be needed including.

But since there is still a wide variety of slate roofing systems there are occasions when the minimum pitch can go down to as low as 15 0 depending on the uniqueness of the roof. There is also the scope to incorporate a green roof onto the flat structure. When installing or repairing a flat roof you must adhere to building regulations. Normally 1 80 0 72 is the recommended minimum angle for a slope and this is universal across the vast majority of flat roofing systems regardless of the materials that they incorporate.

Flat roof this usually consists of felting which has a slight fall to allow rain water to drain off. There are several methods of building in a fall. Flat roof design guide. A qualified roofing contractor will be able to advise on this but here are some of the main guidelines.

A pitch of 10 degrees or less is typically regarded as a flat roof. This applies to general roof areas along with any internal gutters. A flat roof is more likely to allow rain to pool and this can cause damage especially if the roof is made of a porous substance like wood. In order to achieve this drop a slightly steeper angle of 1 40 1 44 should be the aim when installing a flat roof as this accounts for surface deviations and material deflection among other things.

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. Part h of the building regulations regarding drainage state that water should drain to one or two edges. Pitch roof this is where tiles or slates are used and a void is usually created underneath. There must be a slope of 1 80.

The reason for a pitched roof is to cause rain to run off the roof surface. If flat roofs are to work well they have to have a slope known as a fall to shed rainwater. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs.