I'm planning to build a loft and am considering the construction. The loft will be 4x3m, and the idea is for the floor joists to rest on a beam attached to a brick wall on two sides and on a beam resting on a standing beam. I initially considered glulam, but it turned out to be too thick. I'm now considering using RHS (Rectangular Hollow Section) tubes but haven't figured out how to size these. According to the table for "Floor joists, free-span, two supports," glulam would be 42x180 for a length of 3m and 56x225 for 4m C600. Can someone tell me what size this corresponds to in RHS square tubes c600 or c400? Grateful for any help! /Olov
