Basement Rim Joist Insulation
Fiberglass insulation and expanding foam seal the open top of hollow concrete blocks.
Basement rim joist insulation. Insulating the rim joist or band joist area with fiberglass insulation is no longer recommended by building professionals and does not meet current building codes for air sealing. Rim joist foam board insulation. Alternatively the application of a spray foam usually done by a contractor can provide good insulation and air sealing. Spray foam does a great job not only insulating the rim joist but it also seals all the possible air infiltration points.
Foam boards can be used to insulate any part of the home from the roof to the basement walls. The best basement crawlspace or joist insulation. Spray foam insulation is the best way to insulate a rim joist in my opinion. Airtight insulation reduces heat loss through the rim joist band joist.
How to finish a basement wall. Using rigid foam keeps the material costs low but it also requires more labor than using spray foam. Spray foam insulation that s convenient and easy to use. R value of 7 in 1 inch 97 closed cell foam.
However spray foam insulationcomes at a serious price point and it is best left to professional installation. Because fiberglass easily allows air to travel through it is a very poor choice for insulating the drafty rim joist area. If you re ready to insulate the rim joists in your basement or crawlspace you have to decide between rigid foam and spray foam. Rim joist insulation install rigid foam pieces carefully sealing edges and around pipes wires and vents to prevent moisture from damaging wood framing.
Pros and cons foam boards are rigid panels of insulation with the most common types of materials used in making them including polystyrene polyisocyanurate and polyurethane according to the u s. Class i e 84 fire retardant meets building code spec. The rim joist is located above grade and for many years we treated it similar to the wall insulation above by stuffing fiberglass batt insulation in the rim joist bays.