I would like to build a garden shed of 5m x 4m, with a roof with a single slope 33%, the tiles planned weigh 39kg per m2. Is it possible for the frame to simplify it as much as possible by laying only rafters (in the shortest direction 4,20m) and battens, what should be the section of the rafters and what essence to not have any problem of bending?
If you have not already bought your tiles you can put a bituminous canvas covered with corrugated sheets. The installation will be faster and more economical. Otherwise the section of the beams must be 20X8 cm with a distance of 40 cm and the batten must be 4X4 cm. Thus, whatever the wood you will have no problem of bending. Be careful though to choose wood that is dry and to provide a treatment of your frame before laying (if the wood is not already). Fir Class 4 is suitable for this type of work.
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