External Cills for Folding Bi Fold Doors
Our standard upvc cills are available in three sizes 85mm, 150mm and 180mm. The standard size for a normal brickwork aperture is 150mm, which provides a 50mm ( 2" ) overhang, when the back of the door frame is fitted in line with the back edge of the outside brickwork. The 85mm cill, sometimes referred to as a stub cill, is used when the door frame is fitted forward in the brickwork reveal and likewise the 180mm cill is used when the door is fitted further back in the reveal.
If your installation does not require an external cill, please take into consideration, how rainwater will be taken away from the bottom of the door. For installations where a level transition from the inside to the outside is being created, "ACO" [download] drainage systems are the ideal solution and are available from your local builders merchants.