Best Insulation For Between Floor Joists

Check between floor joists if vented and check perimeter walls if unvented.
Best insulation for between floor joists. Rigid foam is the best insulation for rim joists. Ground should be covered with a 6 mil polyethylene sheet. Fiberglass rolls can be placed between joists but the fiberglass itself will need to be cut to fit properly between joists. If you want to insulate a floor assembly by leaving the joist bays empty and installing rigid foam on the underside of the joists here are a few things to keep in mind.
Department of energy recommends r 11 3 insulation under floors in warm climates and an r 25 6 to 8 in cold climates. Turn off the electricity then remove an electrical outlet cover for a view of exterior insulation. Fill the ends of joist bays with rectangles cut from rigid board insulation. Use caulk or foam sealant to seal the joint between the top.
Gaps between the insulation and the floor can. Use foam sealant such as great stuff to seal the joints. You can insulate second floor rim joists following the same steps shown here if you happen to tear out a ceiling during remodeling. Joist bays the open spaces between floor joists are prime hosts for insulation under specific circumstances.
When the basement or crawl space has vents installed insulating joist bays. We chose 2 in thick r 10 extruded polystyrene don t use expanded polystyrene which is a less effective air and moisture barrier. According to the 2012 irc the minimum r value for floor assemblies is r 13 in zones 1 and 2 r 19 in zones 3 and 4 r 30 in zones 5 and 6 and r 38 in zones 7 and 9. Clarification for march 23rd e mail.
Fiberglass insulation is usually the best option though handling fiberglass can be dangerous and it is not the most eco friendly option in some cases. The insulation should press right up against the floor between joists. Installing this type of insulation is an inexpensive and diy friendly project since the materials are designed to fit into the standard width between wall studs attic rafters and floor joists. Exterior walls and floors.