Celotex Insulation | Celotex Insulation Boards

Celotex is renowned for its high-quality insulation solutions, providing a range of products to suit various applications in both residential and commercial buildings. Their insulation boards are designed to offer enhanced thermal efficiency, contributing to the energy efficiency of buildings and helping to reduce heating costs.

What is Celotex Insulation?

Celotex insulation is a high-performance, rigid PIR (polyisocyanurate) board used to reduce heat loss across walls, floors, and roofs. Known for its excellent thermal conductivity, Celotex boards are lightweight, easy to handle, and available in various thicknesses to meet modern building regulations. The GA4000 and CW4000 series are especially popular for new builds and retrofit projects due to their flexibility, fire performance, and environmental credentials.

General Purpose PIR Insulation Boards

Celotex GA4000 series is a versatile general-purpose PIR insulation board suitable for floors, walls, and roofs. These come in standard dimensions of 2.4m x 1.2m, catering to a wide range of thicknesses to fit different insulation requirements.

Insulated Plasterboard

The PL4000 series combines insulation with plasterboard, ideal for dry lining applications. This two-in-one product simplifies installation while providing thermal insulation and a ready-to-decorate surface.

Thermal Bridging Boards

Celotex TB4000 series addresses thermal bridging, offering a solution to prevent heat loss where different building elements meet. These boards can be used in various applications to enhance the thermal performance of the building envelope.

High-Performance Insulation Boards

The XR4000 series is designed for situations requiring high-performance insulation with greater thicknesses. These boards are suitable for projects demanding a lower U-value and can be used in multiple building areas, including challenging spaces.

Cavity Wall Insulation

Celotex offers products specifically designed for cavity walls, such as the CW4000 and Thermaclass Cavity Wall 21, providing an effective way to insulate new and existing cavity walls to improve thermal performance.

Choosing the Right Celotex Insulation

Selecting the appropriate Celotex product depends on the specific use case:

• For general applications, the GA4000 series is a flexible choice.
• For dry lining, the PL4000 series is the best option.
• To combat thermal bridging, the TB4000 series is recommended.
• For high-performance needs, the XR4000 series is ideal.
• For cavity walls, CW4000 or Thermaclass Cavity Wall 21 will serve well.

Benefits of Celotex Insulation

• Superior Thermal Efficiency – Achieves low U-values with minimal thickness, thanks to thermal conductivity as low as 0.022 W/m·K.
• Lightweight Yet Durable – Easy to transport, cut, and fit without compromising structural strength.
• Moisture Resistant – Closed-cell PIR core offers excellent resistance to moisture and damp, improving longevity.
• Certified Performance – BBA-approved and compliant with UK Building Regulations (Part L), ensuring reliability and safety.
• Environmentally Responsible – Features low global warming potential (GWP) and zero ozone depletion potential (ODP), ideal for sustainable builds.

Applications of Celotex Insulation

Celotex boards are highly versatile and suitable for a wide range of residential and commercial applications:

• Internal & External Walls – Between studs or cavity applications using CW4000 series.
• Floor Insulation – Below screed or timber suspended floors to improve energy efficiency.
• Pitched Roofs & Loft Spaces – Between and under rafters or joists to maintain thermal comfort.
• Flat Roof Systems – As part of warm roof constructions with weatherproof membranes.
• Refurbishment Projects – Ideal for upgrades in older homes where space is limited.

Installation Tips

• Cut easily with a fine-tooth saw or utility knife; always measure twice before cutting.
• Fit snugly between studs, joists, or rafters to eliminate thermal bridging.
• Use Appropriate Fixings for walls, floors, or roofs—mechanical fixings or adhesive as per substrate.
• Seal Joints with foil tape or appropriate sealant to minimise air leakage.
• Check Local Regulations and ensure compliance with Part L and other building standards.

Why Choose Build4Less?

At Build4Less, we go beyond just selling insulation—we provide a reliable, builder-trusted experience:

• Fast & Reliable UK Delivery – Get your Celotex boards delivered quickly to the site or home.
• Competitive Pricing – Great value on single sheets and bulk orders with quantity discounts available.
• Expert Support – Need help choosing the right thickness or board? Our insulation specialists are just a call away.
• Wide Range in Stock – From GA4100 to CW4000 series, we stock multiple sizes and types to suit every project.
• Trusted by Professionals – Join thousands of satisfied tradespeople, self-builders, and property developers across the UK.