Ask any builder about the quality of dimensional lumber these days and you're likely to get an ear full. Then mention current lumber prices and you'll likely unleash real excitement, plus a raft of questions about alternative materials. Suddenly those engineered members look pretty attractive. Wood Ibeams, in particular, have a number of advantages over dimensional lumber, not the least of which are the energy advantages. Ventilation Wood I-beams intended for residential use commonly come in four sizes — 91/2, 117/8, 14, and 16 inches. These depths offer ample room for insulation and ventilation in floor and roof assemblies. Getting enough ventilation in a cathedral ceiling, for instance, has always been a challenge with conventional lumber rafters, but is much easier with wood I-beams.
