Best Loft Floor Insulation

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.

Best loft floor insulation.

Gaps between the insulation and the floor can. Fiberglass rolls can be placed between joists but the fiberglass itself will need to be cut to fit properly between joists. The insulation should be pushed tight to the underside of the floorboards. Insulation depends on its loft in order to realize its full r value.

Spray foam insulation is likely the best option for below floor insulation. At least 25mm of the joist must be left exposed to ensure air circulation. The most common form of loft insulation this comes in rolls of rock glass or mineral fibre we use earthwool by knauf which is a really good environmentally friendly option or else foil backed felt. Save 60 50 10.

A semi rigid material is generally best as it can be cut very slightly oversized and squeezed in between the floor joists thereby ensuring no draught causing gaps. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. It s generally the cheapest option and good all purpose insulation especially for between joists. 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.

View the owens corning 2x6 wall floor insulation 544 50 pallet 605 00. This is to prevent the joist. It is the longest lasting and the highest r value insulation that can be put into place. Foam in place insulation is sprayed into spaces between the joists and goes around venting pipes and electrical work.

The most expensive option. You can still board directly on to the joists if you want but it is worth noting that this would not pass a building control inspection because you wouldn t have the full 270mm depth of insulation required by regulations. The insulation should press right up against the floor between joists. Save 60 50 10 544 50 pallet 605 00.

Find your zone on the map and then use the above insulation r value chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. Best seller owens corning thermafiber fire and sound guard mineral wool insulation batt 15 in. Fiberglass insulation is usually the best option though handling fiberglass can be dangerous and it is not the most eco friendly option in some cases.