You provide lots of different sizes, which ones do I need?
We provide a range of sizes in our literature and on our website. The most commonly used size for installation is the "Internal Rafter" dimension. The width dimensions are critical as the fixing lugs are located on the sides of the rooflight however, we do provide around a 55mm tolerance in the quoted internal rafter. This gives the installer an option with the plasterboard. Quite often the installation involves the plasterboard being boxed around the rooflight. However in certain applications the winder may snag on the plasterboard at the bottom of the rooflight thus reducing the distance the winder can open the casement. If your rafters are particularly deep and this is likely to happen, it might be necessary to fit the bottom section of plasterboard at an angle. Providing the tolerance in our internal rafter height makes this process easier. If you do not wish to taper the plasterboard, you can simply add an additional timber piece across the head or cill to fit tight against the rooflight liner. As the end user, you will need to pay attention to the clear viewable size as this is the dimension you have upon completion of installation. These sizes are provided from the internal face of the American oak liner. The overall size is, as you would expect, the size of the complete rooflight. Please remember that much of the outer frame is covered by your slates or tiles, leaving an unobtrusive low profile rooflight in your roof. Should you require any sizing information prior to ordering or installation, please call us on 0845 050 8746.