Should You Insulate Floor Joists In Basement

First you ll have to maneuver batts of insulation around the clutter of wires pipes and cross bracing in a typical basement ceiling.

Should you insulate floor joists in basement.

Properly insulating and air sealing rim joists band joists takes patience so most builders simply stuff in some fiberglass and walk away. Basement insulation bonus tip 1. Check out the guide to insulating basement walls link above. Cut pieces of insulation just large enough to fit along the rim joist the framing material into which all the floor joists are nailed.

Lay down a moisture barrier with sheets of 6 mil plastic if you have a dirt or gravel floor. If you have an unfinished basement you can properly insulate the rim joists in two or three hours. 4b slab floors built directly on the ground. 2 xps foam board against in my case board formed concrete framed up with 2 4 studs with a composite board under the bottom plate as a capillary break.

To prevent these problems only air impermeable insulation either rigid foam or spray polyurethane foam should be used to insulate the interior of a rim joist. When you re using fiberglass batting insulation material run it about 6 inches or so onto the crawl space floor. Hold the batts in place by stapling their paper faced vapor retarders to the lower edges of the joists. Be sure to seal rim joists.

Two story homes usually have another ring of rim joists above the first floor ceiling. 4c as an alternative to floor insulation foundation walls of unvented crawl spaces. 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. If the crawl space is ventilated which is ideal because it aids in the elimination of moisture then fiberglass insulation can be easily installed under the subfloor between the floor joists.

Jerry thanks for the comment getting back to you after the holidays. 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. 4d extend insulation into joist space to reduce air flows. Impervious insulation is always an excellent idea for basement walls but it s absolutely essential where the floor joists of the level above meets outside walls along the edges of a basement ceiling.

This will also block tiny passages where spiders and other insects enter your basement. If you have an unvented crawlspace or basement you must insulate the walls instead of the floor joists. Also insulate 4a any portion of the floor in a room that is cantilevered beyond the exterior wall below.