How do you install PIR insulation between rafters?

Quote from the video:
Quote from Youtube video: Obviously you can rip down any piece of timber to whatever size you require then when we take our insulation or pi bar board and we push that up to the batten.

Do you need an air gap with PIR insulation?

Insulation is technically a solid with a lot of air in it therefore, it is NOT an air gap. You literally must have a VOID, nothing in the air gap except air itself. So if you are installing under a roof or in a wall, you must create an air gap.

How do you fit insulation boards between joists?

Quote from the video:
Quote from Youtube video: So with all the rafters now batten down to give the extra depth of the insulation. We start cutting & fitting all the hundred mil. Board. They're measuring top and bottom there's a bit of variation in

How do I install Celotex between rafters?

How to fit Celotex between rafters in 5 steps

  1. Prepare the roof. Before you start fitting your roof with Celotex, you need to make sure the space is clean and clear first. …
  2. Take all the measurements. …
  3. Create an air gap. …
  4. Cut Celotex boards to size. …
  5. Install stop battens.

Does kingspan need an air gap?

The timbers must be deep enough to allow the desired thickness of Kingspan Kooltherm K112 Framing Board to be fitted between them along with a 25 mm (min.) air gap between the insulation layer and the brick wall.

How do you seal PIR insulation?

Quote from the video:
Quote from Youtube video: Um with tape eventually before i put the overboard in or under boarding on and that way i know all this is sealed up nicely.

Can you put insulation between roof rafters?

You can use rigid insulation boards, carefully cut to size, or you can have foam insulation sprayed between the rafters. Whichever approach you use, you will need a specialist professional to insulate your roof – this is not a DIY job.

Does Celotex need a Vapour barrier?

You must use a vapour barrier otherwise warm air, which contains more water than cold, may get through to the cold outer fabric. If it does, and cools, you’ll get condensation.

How do I keep Celotex in place?

It won’t get loose mate, if you have any concerns another solution is to buy an expanding foam gun(one you turn the nozzle to control the flow), and spray foam up the edges of the rafters, sealing any air gaps and effectively gluing the insulation in place. Also spray all corners and points of intersection.

Which way round does kingspan go?


There you have it. It faces in, it faces out, it faces towards the roof, it faces towards the space, it faces towards the room. And wait for it, it should have foil on both sides, so all is correct, because it can face the room, the ceiling, the roof and the space all at the same time.

Do you leave a gap between roof and insulation?

It is important that air is allowed to circulate between the roof covering and the insulation to avoid condensation – a gap of at least 50mm (2 inch) must be left between the insulation and the inside of the roof covering.

What insulation do you use between rafters?

Normally, people use mineral wool or insulation boards to insulate the rafter space. We prefer recycled insulation for obvious reasons. If you are planning to use wool then it is imperative you wear protective clothing, goggles and a face mask, since the wool is an irritant.

Can I use rockwool between rafters?

ROCKWOOL offers a range of products for installation both between and over the rafters.

Can you use Celotex for loft insulation?

Using rigid insulation board as loft insulation

Some people may prefer to use rigid insulation board to insulate the loft space – for example Celotex or Kingspan – the process is pretty similar to above, although you will need less depth to achieve the same insulation levels (than mineral wool).

Can I put Celotex between the ceiling joists?

Either a rigid PIR board (such as Celotex XR4000 or GA4000) can be cut to an exact fit and installed between the joists, or a more flexible glass mineral wool (GMW) roll or slab from ISOVER can be cut slightly oversize (i.e. 10mm wider than necessary) to ensure a friction fit when installed between the joists.

Can you use PIR loft insulation?

PIR insulation is thermally efficient and can be used as part of a complete refurbishment of the loft floor, or in conjunction with existing insulation laid between the joists, to help improve heat loss from the property and, where necessary, meet the requirements of national building regulations.