How To Insulate Floor Joist Pockets

A merry christmas to everyone.

How to insulate floor joist pockets.

In better insulated situations these cavities are partially filled with high density foam or extruded foam pieces. Properly insulating and air sealing rim joists band joists takes patience so most builders simply stuff in some fiberglass and walk away. I filled the pockets with insulation 2 pieces of fibreglass to total 5 5 inches thick then sealed the pockets with a piece of polyethylene. Insulating rim joists pockets.

Quite often basement perimeter foundation walls are framed insulated and covered with 6mil poly to the underside of the floor joists and loosely stapled in place between these pockets. We live in michigan and its cold now even without the snow. At the rim joist area many building components come together the foundation wall the mudsill the rim joist the subfloor so it s also important to seal all cracks against air leakage. Rim joists are above grade so it makes sense to insulate the joists to the same level as above grade walls.

Have a question about insulating my rim joists in basement. This is an effective method for air sealing this area while still being easy on the pocket book. In cold humid or mixed climates the foam board thickness needs to be 2 thick to stop the condensation in the rim joist area. This may be a bit long so bear with me.

If the foam board is properly sealed additional fiberglass. On one side of my house where the joist runs parallel to the outside wall i insulated and put poly part way only but could not seal it because of a. The pockets between the joists were not insulated. We have a ranch with a full basement and craw space.

Sealing and insulating rim joists.