Understanding Building Regulations for fire-rated rooflights

A fire-rated rooflight is a window that is installed within a pitched roof or flat roof, to allow more light rooms or spaces within your home or property.

For this blog, we will explore the rules rooflights need to adhere to under Building Regulations.

How fire-rated rooflights adhere to Building Regulations

Approval under the Building Regulations is generally required for the installation of new rooflights. Here are the reasons -

Structure - The installation of skylights on your roof generally entails cutting part of one or more of the roof's rafters or joists away. The cut ends of the rafter/joist require new support, which is achieved by fixing two pieces of timber together to span across the new opening on either side. These double timbers are referred to as 'trimmers'.

The adjacent rafters or joists that are fixed to these trimmers also need strengthening as they will be supporting the load transferred from the cut rafters or joists. This strengthening is achieved by fixing a new rafter or joist to them, which is full-length.

Weather Proofing - Once your rooflight is installed, the edges will need weatherproofing plus the glass of the rooflight itself. This typically requires the use of lead flashing or proprietary kits that come with the rooflight. Natralight will be able to advise on how this can be carried out.

Ventilation - A room where the rooflight will be based needs to be ventilated, which can be achieved by using it for both rapid and background venting.

Ventilation of the existing roof void(s) need to be considered as air must also be allowed to flow from one to another.

Energy Conservation - Dwellings are required to be energy efficient, as this reduces the amount of heat that is lost through the glazing in both windows and doors.

If you are having windows and doors installed, you should also be aware of the Building Regulations in relation to the amount of heat passing through the door or window, including the frame (which is measured as a U-Value). This U-Value cannot be exceeded. For further information about maximum U-Value allowed, refer to Approved Document L-1B, Table 1.

Need more information? Get in touch today

If you have further questions about fire-rated rooflights or Building Regulations, please do not hesitate to contact Natralight today. We have over three decades of experience providing the finest quality rooflights to customers all over the country.