One of the common areas of advice we are asked about at The Plastic People is about which polycarbonate to use for roofing projects and how much will be required.
Twin-wall and multi-wall polycarbonate is the plastic material that is a popular choice for roofing projects because it is so light making it easy to install; so strong it is virtually unbreakable and it offers some insulation too. More about the benefits of twin-wall and multi-wall polycarbonate can be read here.
To work out how much twin-wall or multi-wall is needed for your roofing project it is best to begin with a drawing of your roofing area so you can calculate the size of the area that you need to cover.
Decide where your rafters will go – the narrower the width between your rafters the stronger your roof will be. As a guide, choose 16mm multi-wall at minimum if your support rafters are 980mm apart. Due to varying pitch factors, wind loading and snow loading we recommend that 1050mm is the maximum distance between rafters. The narrower the widths the stronger your roof will be.
Choose your multiwall polycarbonate sheets. Sheets suitable for roofing are available as 16mm and 25mm thick and upto 5m x 2m. You can buy them cut to the size you need or you can cut them yourself with a fine tooth jigsaw or circular saw.