50mm Celotex CW4050 - Rigid PIR Cavity Insulation Board (pack of 11) CW4000
50mm Celotex CW4050 - Rigid PIR Cavity Insulation Board (pack of 11) CW4000
Price: £65.48 (£78.58 inc VAT)
Price per m2: £11.02/m2 (£13.23 inc VAT)
10 or more £64.41 (£77.29 inc VAT)
15 or more £63.35 (£76.02 inc VAT)
20 or more £61.72 (£74.06 inc VAT)
- Product Code: A1-159
- Delivery Time: 1 - 5 working days
- Brand: Celotex (Tech. support: 01473820850)
- Model: 1200mm x 450mm - 5.94m2
- Weight: 9.36kg
Our ratings on 17-12-2025:
4.8 out of 5
50mm Celotex CW4050 - Rigid PIR Cavity Insulation Board (pack of 11) CW4000
Width: 450mm
Length: 1200mm
Density: 31.5kg/m3
Weight/m2: 1.58kg
Weight: 9.36kg
Thermal Conductivity: 0.023W/mK
R-Value: 2.25m2K/W
Compressive Strength: 120kPa
50mm Celotex CW4000 is an insulation board aimed specifically at partial fill cavity wall applications. It comprises a polyisocyanurate rigid foam insulation core, with a thermal conductivity of 0.022 W/mK and low emissivity aluminium foil facings on both sides. CW4000 is manufactured from rigid polyisocyanurate (PIR) using a blend of blowing agents that have zero ozone depletion potential (zero ODP) and low global warming potential (GWP).
Note: Would be known as CW3000 from January 2018.
APPLICATION
Celotex CW4000 is specifically for use in partial-fill cavity wall applications.

CHARACTERISTICS
- Is easy to fit between wall ties using cavity tie clips for retention
- Comes in thicknesses ranging from 25mm-100mm
- Comes in conveniently sized boards for installation between cavity wall ties
- Includes low emissivity foil facings giving improved thermal insulation performance within cavity air spaces
- Has excellent dimensional stability
- Provides reliable long term energy savings for buildings
CERTIFICATION
- The insulation component of Celotex CW4000 is A+ rated when compared to the BRE Green Guide 2008
- Celotex CW4000 is CFC/HCFC free with zero ozone depletion potential (ODP) and low global warming potential (GWP)
- Celotex CW4000 received CE marking compliance to BS EN 13165:2001
- The board is manufactured in accordance with quality management systems with BS EN ISO 9001:2000 by Celotex Limited
Brand: Unilin (prev. Xtratherm)
Model: 2400mm x 1200mm - 2.88m2
Delivery Time: 1-3 working days
50mm Unilin Thin-r XT/PR-UF has a core of polyisocyanurate (PIR) bonded to low emissivity textured aluminium foil facings. Unilin XT/PR-UF board offers excellent insulation performance with excellent thermal conductivity. Unilin XT/PR-UF is CFC & HCFC free and is manufactured under the high..
Guide Price: £22.40
£26.88 inc VAT
Brand: Iko
Model: 1200mm x 2400mm - 28.80m2
Delivery Time: 2 - 3 working days
50mm IKO Enertherm ALU PIR Rigid Insulation Board is a versatile insulation board with a rigid polyisocyanurate (PIR) foam core, clad on both sides with reflective aluminium. The seven-layer gas-tight aluminium lamination enhances resistance to fire and water ingress. It’s made without CFC, HCFC, o..
Brand: Celotex
Model: 2400x1200mm - 2.88m2
Delivery Time: 1-3 working days
Celotex XR4110 is targeted at cut-to-fit applications between rafters or joists and enables users to achieve lower U-values with a single layer of insulation than has previously been possible. XR4110 is also appropriate for use in floors and walls. With low emissivity foil facings, XR4110 is ma..
Guide Price: £50.96
£61.15 inc VAT
Brand: Celotex
Model: 1200x2400mm - 2.88m2
Delivery Time: 1 - 5 working days
77.5mm Celotex PL4065 is a high performance thermal insulation board where the 65mm PIR insulation is bonded to 12.5mm tapered edge plasterboard. PL4000 is manufactured from rigid polyisocyanurate (PIR) using a blend of blowing agents that have zero ozone depletion potential (zero ODP) and low globa..
Guide Price: £81.40
£97.68 inc VAT
Brand: Celotex
Model: 1200mm x 450mm - 4.32m2
Delivery Time: 1 - 5 working days
60mm Celotex CW4000 is an insulation board aimed specifically at partial fill cavity wall applications. It comprises a polyisocyanurate rigid foam insulation core, with a thermal conductivity of 0.022 W/mK and low emissivity aluminium foil facings on both sides. CW4000 is manufactured from rigi..
Guide Price: £68.79
£82.55 inc VAT
Brand: Celotex
Model: 1200x2400mm - 2.88m2
Delivery Time: 1-3 working days
Celotex TB4035 is targeted at cut-to-fit applications between rafters or joists and enables users to achieve lower U-values with a single layer of insulation than has previously been possible. TB4012 is also appropriate for use in floors and walls. With low emissivity foil facings, TB4012 is manufac..
Guide Price: £51.21
£61.45 inc VAT
Brand: Celotex
Model: 2400x1200mm - 2.88m2
Delivery Time: 1-3 working days
Celotex XR4140 is targeted at cut-to-fit applications between rafters or joists and enables users to achieve lower U-values with a single layer of insulation than has previously been possible. XR4140 is also appropriate for use in floors and walls. With low emissivity foil facings, XR4140 is ma..
£40.25
£48.30 inc VAT
Brand: Celotex
Model: 1200x450mm - 3.78m2
Delivery Time: 1 - 5 working days
70mm Celotex CW4000 is an insulation board aimed specifically at partial fill cavity wall applications. It comprises a polyisocyanurate rigid foam insulation core, with a thermal conductivity of 0.022 W/mK and low emissivity aluminium foil facings on both sides. CW4000 is manufactured from rigi..
Related Products
Brand: ZVM
Model: 50mm
Delivery Time: 1 - 2 days
50mm Aluminium Self Adhesive Tape is a high performance sealant tape for foli faced insulation. Adhesive/sealant applied to one side of an aluminised ..
£5.59
£6.71 inc VAT