The PVC Capped Timber Supported Rafter Bar is probably our best seller when considering polycarbonate support options. 3 or 4 metre lengths are the most popular bars although these bars are also available in 2, 2.5, 5 or 6 metres.These bars can be used with polycarbonate sheets between 10mm and 25mm thick. The bar comes in two parts, the aluminium base is fixed to a timber (or metal) rafter and then the sheet is fitted in place before the top cap can be snapped down accordingly.Available in both white and brown.Further information on our rafter bars can be found in our Guides and Tips section here.