How to fit FAIRs rooflights

Transcript

FAIRs rooflights are made to measure and cannot be adjusted on site. Measurements need to be accurate to the millimetre.

Firstly, you’ll need to know the distance between the centre of each purlin so that the foam block inside the rooflight sits directly above them. You’ll need to add on 150 millimetres as an overlap at the bottom. As a rule of thumb, you shouldn’t run a rooflight from ridge to eaves. As you can see here, we have a bottom sheet rooflight, and top sheet. The total length of these three sheets must mast the full length panels on either side. Take care when handling the panels, they’re constructed by hand and can be easily damaged.

Before we begin fixing, apply 3 continuous beads of high-grade, butyl lap mastic across the width of the sheet. You’ll need 2 runs either side of where the fixings will go, and a third run 10mm up from the nominal edge.

Now the lap mastic is in, we can begin to fix the panel down. It’s really important to use a 29mm washer, this will create a watertight seal and spread the force of the fixing across the sheet. Use 2 fixings per trough across the sheet on each purlin. Don’t over or under tighten as this will either divot the sheet or not compress the washer correctly.

With the bottom of the rooflight secure, it’s time to fit the top sheet. Lay the lap mastic in the same way, only this time we’ll be fixing through the foam block of the rooflight into the purlin. To fix the lapping detail, use a stitching screw that will self-tap into the sheet. This will be on the overlap and the end lap. As you can see, we’re using red caps all around the rooflight to meet building regs.

Now the FAIRs rooflight is installed and weather tight, you’re ready to install the rest of the roof.