Post by troycethers on Jul 24, 2019 23:27:52 GMT
Even though hot air rises, homes lose heat in all directions. So besides insulating the top and sides of your house, you also need to insulate the bottom, where as much as 30% of energy loss can occur. As with the attic, you have two choices: Insulate under the bottom floor and treat the crawl space or basement as outdoor space, or insulate the walls and treat the area as indoor space. In that case, you would close off all exterior vents except those needed for combustion air or exhaust.
Though floor insulation is more common, wall insulation has many advantages, including cost—it takes about a third less material to insulate the walls of a 36-by-48-foot basement as to insulate the subfloor above. A key detail, not understood by all builders, is to place a layer of rigid foam insulation against the foundation to keep moisture from condensing against the cold walls. If you want to finish the basement, you can cover the foam with a stud wall, fill it with unfaced fiberglass insulation, and cover with drywall.
Though floor insulation is more common, wall insulation has many advantages, including cost—it takes about a third less material to insulate the walls of a 36-by-48-foot basement as to insulate the subfloor above. A key detail, not understood by all builders, is to place a layer of rigid foam insulation against the foundation to keep moisture from condensing against the cold walls. If you want to finish the basement, you can cover the foam with a stud wall, fill it with unfaced fiberglass insulation, and cover with drywall.