Install it anywhere from the roof to the foundation.
Rigid foam insulation under floor joists.
The insulation should cover the whole depth of the cavity and contact with the floor.
Instead of installing the foam insulation between floor joists in the crawl space the foam board is installed against the crawl space foundation walls.
That would need 90mm of rigid foam or 150mm mineral wool.
Installers should push the insulation up and fasten it to prevent any void or gap between the floor and the material.
The insulation should be pushed tight to the underside of the floorboards.
You can even place it under the foundation slab.
Rigid insulation is one of the best tools to reduce your energy costs.
Insulated rim joists place rigid roam against the rim joists then caulk along the insulation.
Fiberglass insulation and expanding foam seal the open top of hollow concrete blocks.
Unlike fiberglass rigid foam insulation does not absorb water support mold or allow air to pass through providing that joints between boards are sealed with tape.
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.
They keep your home at a comfortable temperature without the need to crank your heat.
If it you need to spread it use a brush to help cover and smooth out the glue.
Installing fiberglass or mineral wool batts or rigid foam boards in floors with exposed joists open floors is straightforward.
Airtight insulation reduces heat loss through the rim joist band joist.