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Carpentry & Joinery Question
Roof timber spans
I have some surplus 5x2 timbers which I would like to use to form the roof of my shed/kids play house in my garden ideally I would like the span to be 3.3 I have looked and the recommended max span seems to be about 2.5m, is there anything I could put under to achieve this span, I'd rather not build any partitions under as I wNt one big room 3.3m x 7 m in total
Hi Graham, a very good rule of thumb for joist sizes and spans is;
For a 2" timber thickness- measure the span in feet, divide by two, convert to inches
and add two. Therefore your 3.3m span is 11 feet which is 5 1/2 then add 2 = 7 1/2 "x2".
You could double up the 5x2 or fit midway lintel of say two 8x2 timbers with a 4x4 post under to span the 7m.
Answered 17th Mar 2013