37.5mm Celotex Insulated Plasterboard PL4020 (1200mm x 2400mm)

6 customer reviews

£39.32 ex VAT

Est. Delivery: 2 – 3 Working Days
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Get the best prices on insulated plasterboards here! Celotex 37.5mm is a quality product made up of a polyisocyanurate (PIR) core with a foil lining on one side and a paper lining on the other. The foil-lined side of the sheet is bonded to 12.5mm plasterboard. The plasterboard is made up of a Gyproc core with quality paper linings.


  • Celotex as a brand is renowned for its quality products and reliable services
  • Their high-quality products manufactured are virtually impossible to beat in price!
  • Celotex insulation has better thermal efficiency than many other materials
  • The Celotex brand offers materials to suit a wide range of applications including, pitched roofs, flat roofs, walls, floors, and ceilings.
  • Other Celotex product include Thermaclass, cavity wall boards, and insulation boards

37.5mm Insulated Plasterboard

  • 37.5mm – Product code PL4025
  • 25mm Insulated Plasterboards are one of the best-selling products in construction market
  • The bonded Plasterboard has a tapered edge for an easier and more durable completion
  • This is a 2-in-1 product means you can improve thermal quality of the building and apply a wall finishing in one application
  • Insulated plasterboards are lightweight making them super easy to handle, cut, and install, this versatile product can be installed within domestic or commercial buildings
  • This product is a 12.5mm plasterboard and 25mm insulation board. This thin board is a great way to make the most of your space
  • This size is the most popular due to its practical size, this 37.5mm is also cost effective
  • This board offers an incredible thermal conductivity of just 0.022W/mK – which for those who don’t know, means very small amount of heat can pass through the board, keeping the heat inside your home or office!
  • Whilst staying warm in the winter and cool in the summer, you’re also providing an energy efficient environment that contributes to the reduction of climate change
  • While you think it stops at helping the environment, with less heat escaping, Celotex insulated plasterboards can also save you money on your energy bills
  • These boards can be applied to walls and pitched roof applications in either a dot and dab or mechanical fixing application
  • The insulated plasterboards are also available in sizes 52.5mm, 62.5mm, 72.5mm, 77.5mm to suit every application need
  • All Insulated plasterboards are CFC, HCFC and Formaldehyde Free with zero ozone depletion potential (ODP) and low global warming potential (GWP)
  • Don’t be surprised if you see Insulated Plasterboard referred to as the following, Thermal laminate, Thermaline Boards, Insulation backed plasterboard, Thermal PIR Board.


  • Reaction to Fire: Euroclass B-s1
  • BS EN 13501-1
  • CE Marked (18.DOPPL4000-01) to BS EN 13950
  • BBA Approved (Cert no 16/5357)
  • Achieves a BRE Green Guide A+ rating
  • Quality Management Standard – ISO 9001:2015

More Information:

  • Product code: PL4025
  • Thickness: 12.5mm + 25mm (37.5mm)
  • Size: 2400mm x 1200mm
  • Materials: Gypsum, PIR, Foil, Paper
  • Thermal Conductivity: 0.022W/mK
  • R-Value: 1.20 m2.kW
  • Piece per Pallet: 52

How are insulation boards installed in wall applications?

Insulated plasterboard can be installed using the dot and dab method however the most used method of installing insulated plasterboards is to mechanically fix the boards onto timber battens. See below.

Step 1:

Fix the timber battens at the floor and ceiling around the entire room. Then go on to fix the battens around door and window openings and vertically around the room at 600mm apart. Fix the battens 75mm from its end. Every batten should have a minimum depth of 25mm and width of 47mm. Back the battens with a damp proof course (DPC).

Step 2:

Cut the insulation boards to the required size. The boards should be cut 5mm short of floor to ceiling height.

Step 3:

Fit the insulated plasterboard, at sheet joins, lap them over the timber battens so the two sheets meet at the centre point of the batten. Tightly but the boards with fixings no less than 10mm from the edges of the board. Fix drywall screws at 300mm centres. Or large-headed galvanised clout nails at 150mm centres. Make sure the fixings do not go all the way through the timber. A penetration through the board and 22.5mm into the timber frame should be enough.

Step 4:

Seal the perimeter of the insulated plasterboard with a flexible sealant or the equivalent product. Go on to complete the wall using plaster and adhesive compound. Add paint and keep the walls plain or add a bolder touch to suit your taste with wallpaper.

Is it cheaper to buy insulated plasterboard?

Yes, buying insulated plasterboard is a cheaper alternative to buying insulation boards and plasterboards separately. It also makes an easier process and quicker installation by handing, cutting, and fitting one product instead of two, this means less waste.

How do you cut insulated plasterboard?

The best and easiest way to cut insulated plasterboard is to measure and mark the board to size and then scored the insulation side, cutting through to the paper back of the plasterboard with a sharp knife, snap the board over a hard edge and score the other side. A fine-toothed saw can also be used to cut the boards.

What size do I need?

The size you need will depend on the space being insulated. Thicker insulation is always the best option to achieve the best thermal conductivity possible however a thinned board will also improve the thermal conductivity. This decision is really based on how much space you want to save, and if the board meets the building regulations.

Additional information

Dimensions2400 × 1200 mm




Material Type

Polyisocyanurate (PIR)

Pieces Per Pack


Sales Unit


Unit Coverage


Manufacturers Reference


Thermal Conductivity




Fire Rating

Euroclass B

Edge Type



Paper Facing

Weight (kg/m2)


6 reviews for 37.5mm Celotex Insulated Plasterboard PL4020 (1200mm x 2400mm)

  1. David Burrows

    Ordered 30 sheets of Celotex Insulated Plasterboard 37.5mm – great product and very easy to use, highly recommend this

  2. Samantha Jones

    Purchased 37.5mm Celotex Insulated Plasterboard from Trade Insulations for our self-build project, me and my husband was very happy with this product saved us so much time and money.

  3. Dave Spokes

    Brilliant product, really easy to work with.

  4. KOMAL

    Cant beat these prices at the minute, defo will be ordering the next lot from here.

  5. Daniel Hallis

    Really quick turn around and smooth delivery.

  6. Karman Prescot

    Excellent Service

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