subfloor and heating ducts
is there any problem with heating ducts coming in contact with floor joists,plywood subfloor etc ? I know the ducts don't get very hot but I DO notice that the heating ducts I have exposed under my kitchen subfloor seem to be centered in the space between joists. maybe that's just good construction practice,huh? also, may be a silly question, but what purpose do those pieces of wood between the joists serve? you know, the pieces in the shape off an X. they sure don't seem to be doing much.