Polycarbonate is a high performance material very well suited for roofing.
Polycarbonate sheets have been designed for both domestic and commercial markets and there are many glazing systems now that support polycarbonate sheets since polycarbonate has grown as a popular choice. Its popularity has grown because it is 200 times stronger than glass and yet also much lighter, is shatter proof, has UV protection built in and transmits upto 90% of available light. In addition, it is quicker and easier to fit than traditional glazing and offers a much nicer and longer lasting finish than corrugated sheets.
How does a polycarbonate roof work ?
Polycarbonate sheets themselves are never actually screwed to anything: they ‘clip in’ to a glazing system which offers you a quick method of fitting.
Glazing systems typically consist of pvc or aluminium bars which have a top and bottom section. The bottom sections of the glazing bars should be screwed along the centre of your roof joists.
Have your polycarbonate sheets cut to fit between them and lay them into place. The top sections of the glazing bars clip on once the sheets are in place, in effect ‘capping’ the joint and holding the polycarbonate sheets in place, allowing for expansion in hot weather and contraction in cold weather.
When you fit your polycarbonate roof you will need a sealant to attach capping bars onto the bottom edge of your roof. Choose a non-hardening sealant which is safe to use with plastic / polycarbonate. Using other sealants could crack, discolour or make your polycarbonate brittle.
Choosing Your Polycarbonate
Because your polycarbonate sheets need to fit between your roof joists it is important to make careful measurements and get the right size. You can either buy polycarbonate sheets suitable for roofing and cut them (despite its impressive strength, you can cut polycarbonate roof sheets fairly easily yourself using a fine toothed saw) or buy the polycarbonate at the sizes you need. The Plastic People can help you with either option if you would like.
In addition polycarbonate sheets can be cut to any shape making it suitable for many styles of roofs. Polycarbonate can be cut into triangular shapes making it suitable for gable end roofs (typically a gable is the triangular portion of a wall between the edges of a sloping roof); lean-to-roofs (typically a roof with a single slope), Edwardian and Georgian roofs as well as canopies.
Canopies are usually supported by your house / building to which they are attached and by two or more support posts. If you would like help with any special shapes feel free to ask the friendly advisors at The Plastic People.
- 4mm polycarbonate for greenhouse, cold frames and sheds
- 10mm polycarbonate for carports, pergolas and sheds
- 25mm and 35mm polycarbonate for conservatory roofs
Your polycarbonate sheets should be covered with a protective film. This should be left on until you fit the sheet. The top and bottom end of the sheet will also be capped when the sheet is whole. If you are cutting the sheet, try to keep the top end capping in place; cover the cut end with some perforated self adhesive tape. A plastic cover bead can finally be fitted over the tape (with your non-hardening sealant) to capping the end.
A last important note: keep moisture from entering the flutes in your polycarbonate. If you are storing polycarbonate before use choose somewhere dry (not outside or on wet grass).