In cold humid or mixed climates the foam board thickness needs to be 2 thick to stop the condensation in the rim joist area.
How to insulate floor joist pockets.
Properly insulating and air sealing rim joists band joists takes patience so most builders simply stuff in some fiberglass and walk away.
A merry christmas to everyone.
This may be a bit long so bear with me.
We have a ranch with a full basement and craw space.
Use a box cutter to cut the insulation to length.
The pockets between the joists were not insulated.
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.
Have a question about insulating my rim joists in basement.
Have work shop and family room downstairs it seems to get chilly after.
In better insulated situations these cavities are partially filled with high density foam or extruded foam pieces.
If you have an unfinished basement you can properly insulate the rim joists in two or three hours.
We live in michigan and its cold now even without the snow.
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.
If the foam board is properly sealed additional fiberglass.
This is an effective method for air sealing this area while still being easy on the pocket book.
Sealing and insulating rim joists.
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.