PVC / Polycarbonate sheet roofing
Pvc and polycarbonate sheet roofing come in a variety of profiles, sizes, and colors. Quality and prices vary immensely.
The most common profile is corrugated.
Quality varies enormously from cheaper pvc sheets up to lifetime guaranteed polycarbonate sheets and the price varies accordingly. Guarantees range from zero to lifetime.
Sometimes the cheapest is not the most cost effective. Pamphlets relevant to the type of sheeting required are usually available from most stockists, it is advisable to read them.
Most type of PVC or polycarbonate manufacturers recommend a 10 degree pitch (approx 1 in 5.7 fall).
A lesser pitch could require additional weatherproofing such as extra flashings or appropriate sealants.Cutting
Garden scissors or a fine tooth saw can be used to cut most sheets. The higher the quality, the easier the cutting. Sometimes a carborundum blade on a disk grinder will do the trick but only one sheet at a time or it could cause fusion and weld the sheets together.
Pre-drill the holes in the sheets before fixing. The holes should be 8mm (5/16″) to 10mm (3/8″) and at least 2mm (1/8″) larger than the shaft of the screws to allow for expansion and contraction. Ensure the holes are in the high part of the corrugation. Sometimes it might be easiest to lay the sheets upside down on the ground and pre-drill. Another tip is to use a stick with a hole in it as a guide for the drill.
Appropriate screws are readily available from any suppliers that stock the PVC or polycarbonate roof sheets. If the choice is available, hexagonal heads are the easiest to use. Most sheets should be fixed at every fourth corrugation and every second corrugation at gutters, ridging and overlaps.
Accessories such as ridge flashings, apron flashings and foam eave fillers are also readily available from any suppliers that stock the PVC or polycarbonate roof sheets.