Loft Insulation Between Roof Joists

But if you plan to use your loft for storage only then a conventional cold roof option where the mineral wool insulation rolls are placed in between the ceiling joists above the top floor.

Loft insulation between roof joists.

A cold deck flat roof will typically require insulation to be installed between the roof joists to comply with building regulation requirements. Lay mineral wool between the joists and then fit rigid insulation boards across the joists with floorboards on top. The simplest and cheapest loft insulation solution is the classic cold loft option. If the loft is going to be used as living space then the insulation should be placed at rafter level to create a warm roof.

Joists are the horizontal beams which make up the floor. You could even buy insulation and floor boards that are already bonded together which makes the job much faster and easier. Most insulation you buy will be partially perforated allowing you to cut the roll of insulation easily to produce either 2 rolls that are 570mm wide or 3 rolls that our 380mm wide. Typically the gap between the joists is either 380mm or 570mm so you will need a width of insulation similar to this so it can fit snugly between the joists.

Between and under joists. Rolls of mineral wool can be used if the joists in your loft are regular. The first layer of wool is placed between the joists and then a second layer is placed at right angles which covers the joists and also makes the insulation up to the correct depth of 270mm. To increase the thickness of your roof insulation layer you can.