Recent content by CobraPhil

It should be screwed with one fastener next to each rib. If it is 9" o.c. ribs and is Grade E steel, you can span 8' truss spacing with blown-in insulation. If it is a D grade or less, or rib spacing is 12", it needs to be screwed every 4'....so if you have 24" o.c. trusses screw every other one.