If you prefer, an open grid of 1 x 3 can be built, then topped with traditional plywood, or slightly less traditional extruded-foam insulation board. Sometimes ... In the cases of Homasote and ...
See Figure 1 for a look at how it all goes together. Before you start cutting boards and pounding nails, put together a flat work surface such as a 4x8 sheet of plywood on sawhorses ... insulate the ...