Insulating Floor Trusses

Gaps between the insulation and the floor can lead to inefficiency and heat loss.

Insulating floor trusses.

I have 18 open web floor trusses installed in a unconditioned garage with a conditioned room planned for above. You can insulate second floor rim joists following the same steps shown here if you happen to tear out a ceiling during remodeling. Also insulate 4a any portion of the floor in a room that is cantilevered beyond the exterior wall below. The insulation should press right up against the floor between joists.

Kingspan vips offer an ultra thin build up of just 26mm image credit. Rigid foam is the best insulation for rim joists. Yes it s expensive but as soon as you have you re trusses in and sub floor down you could insulate and leave it exposed until you get to the garage ceiling. If you want to insulate a floor assembly by leaving the joist bays empty and installing rigid foam on the underside of the joists here are a few things to keep in mind.

4d extend insulation into joist space to reduce air flows. Would greatly appreciate the collective advice from the readers of gba on the following. Any compromised floorboards or joists can also be replaced as part of the retrofit project. The fiberglass will also need to be secured in place using wire mesh twine wood laths or other securing methods which can be an intensive project that adds to the overall cost.

4b slab floors built directly on the ground. Have had many opinions from insulation reps on how to insulate. Installing roll insulation in ceiling of basement which is under floors of living space my basement is heated but a smaller amount than up in living space usually 66 68 upstairs and 58 60 at the same time in basement my question is about the kraft paper facing i think it should face the basement because of any moisture in basement. Foam flash batt blown cellulose fiberglass sprayed rock wool and fiberglass batts.

4c as an alternative to floor insulation foundation walls of unvented crawl spaces. Kingspan installing insulation on top of the floor can present problems with ceiling door and window cill heights. When the basement or crawl space has vents installed insulating joist bays. Joist bays the open spaces between floor joists are prime hosts for insulation under specific circumstances.

In some cases if the floor is accessible from below it may also be possible to partially insulate the joists from underneath which offsets thermal bridging through timber members but this is not often the case. 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.