Best Insulation For 2x8 Floor Joists

Owens corning has a 23 x39 roll of pink unfaced insulation that fits between trusses joists or studs adds 6 1 4 thick of insulation with an r 19 value and an nrc rating of 1 05.

Best insulation for 2x8 floor joists.

Ground should be covered with a 6 mil polyethylene sheet. The insulation should extend all the way down to the basement floor or at least to below the frost line the depth to which the ground freezes in winter. It is moisture and mold susceptible though. Gaps between the insulation and the floor can.

Check between floor joists if vented and check perimeter walls if unvented. 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. The floor joists are all fastened to the rim joist which runs along the. Insulation radiant and vapor barriers insulating 2x8 floor on 16 centers from what i m reading hamilton county tennessee only requires r19 for the floor but i can achieve r25 with 2x8 s.

When you are insulating two by four 2x4 and two by six 2x6 framed exterior walls and want to use fiberglass insulation what thickness is best the question becomes all more critical because of the permanent nature of wall assemblies and wall insulation. 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. Turn off the electricity then remove an electrical outlet cover for a view of exterior insulation.

Exterior walls and floors. When insulating basement walls don t forget the band joist the piece of wood at the top of the wall that extends around the perimeter and encloses the ends of the floor joists. Fiberglass rolls can be placed between joists but the fiberglass itself will need to be cut to fit properly between joists. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task.

Trim pieces of fiberglass insulation using a utility knife so the pieces fit into joist bays along the rim joist.