23-02-2014, 06:41 PM
From the timber higher rise timber buildings Ive seen they use alot of those timber "I" beams that are 2 proper bits of wood (like 2x2) with a board down the middle to make the beam. The load transmitted long ways down down the length of the proper wood with the grain is the way its strongest under compression. IIRC the outer skin being nailed to it tight is like a drum skin and actually adds to the strength too. Finally they are uber light compared to cast concrete and as its lighter it doesnt have to be as strong.