Hi berkovius, Standard size for sheets of ply/osb is 1.2x2.4m so you will have to find a way of extending the boards to fit 2.5m. If you use OSB you will have to select the correct grade e.g. exterior grade. 11mm is probably too thin, so use 18mm but you will need joists to support the board edges. 25 year felt will probably be the best covering. Regards S
Hi berkovius, Use the cheapest sheet material you can buy - probably 9mm osb. You may need extra bracing and the weathered face must be painted with some form of paint/varnish. Look out for multibuy offers which can help with savings. Regards S
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!