Design a Douglas Fir Larch (No. 1) wood joist with a span length (center line of bearing to centerline of bearing) of 16 ft. The joist is part of a floor system with a joist spacing of 16 in. The beam is supported on 2x6 members (placed flat).

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.