Maximum Roof Pitch Building Regulations

Thatch is used occasionally on new dwellings and demands a roof pitch of at least 45 and more likely 50 to allow the rain to flow off quickly and prevent ingress.

Maximum roof pitch building regulations.

Metal roof shingles require a minimum roof pitch of 3 12 or greater. Although building codes do not directly prescribe maximum allowable roof slopes fire classifications which are required by code often do include maximum roof slope limitations. The bottom must be 18 inches and the top layer a minimum of 36 inches wide. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs.

It may also be influenced by the nature of the roof covering. For closed valleys valley covered with shingles. To enable compliance with the requirements of the building regulations to be demonstrated full details of the new roof will be needed including. This steep pitch is also an essential ingredient of cottage style.

For example some epdm membrane assemblies have maximum roof slope limitations as low as 1 2 12. Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater. Talk in terms of pitches and you will always be understood in the roofing universe. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

Modern tiles permit shallow pitch but some of the older traditional coverings such as hand made clay tiles require quite steep slopes to ensure rain does not penetrate the roof covering. These factors include the pitch of the roof the type of slate being used the size of the lap the size of the slate as well as the site s exposure rating. Flat roof this usually consists of felting which has a slight fall to allow rain water to drain off. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.

The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. The angle of the pitch may be dictated by aesthetic or structural factors. If a roof increases in height by four inches for every foot of horizontal run it is considered to have a 4 in 12 pitch or just a 4 pitch. Asphalt shingles require a minimum roof pitch of 2 12 or greater.

Let us recap on the minimum roof pitch required for each type of roofing material.