Description

Kooltherm K5 External Wall Board

A premium performance insulation with a fibre-free rigid thermoset phenolic core, it is suitable for use behind traditional and lightweight polymer modified renders.

Fire Rating

Euroclass C-s2, d0

Kingspan Kooltherm thermal conductivity

Application

• Solid brick wall
• Solid block wall
• Cavity block wall
• Cavity brick wall
• Cavity dense block wall

Technical Specifications Of Kooltherm K5 Insulation Board

Kooltherm K5 insulation board is a premium performance insulation choice for external insulation work on masonry walls. To support informed decisions, the key points of kingspan kooltherm k5 external wall products can be grouped into the most important technical areas.

Core specifications:

• A rigid phenolic core that delivers strong thermal performance across a wide insulation thickness range
• Thermal conductivity of 0.022 W/mK for 25 mm to 44 mm and 0.021 W/mK for 45 mm and above
• A Euroclass C s2 d0 fire rating for the kooltherm k5 external wall range

Product sizing and build quality:

• Standard 1200mm x 600mm insulation boards suitable for external wall use
• A glass tissue facing on both sides to support bonding in external wall insulation systems
• Manufactured to quality management systems supporting consistent results across all construction products

Kooltherm K5 insulation board is designed for external wall insulation ewi setups where strong thermal performance is needed without compromising internal space. It remains suitable for use behind traditional and lightweight polymer modified renders as part of refurbishment projects or new masonry walls.

Features And Applications Of K5 External Wall Insulation Board

Kingspan kooltherm k5 external wall products are recognised for their lightweight insulation design and their ability to support external wall insulation work across a wide project range. The following points highlight the main advantages and uses for these insulation materials.

Key features:

• A rigid insulation board that offers strong thermal performance for external wall insulation systems
• Helps reduce heat loss by forming a continuous insulated layer across the external wall
• Suitable for use behind traditional and lightweight polymer modified renders in thin coat finishes

Application uses:

• Effective for external insulation on existing buildings and retrofitting projects carried out externally to existing properties
• Works on solid brick, solid block, cavity brick, and cavity block walls
• A practical option where extremely thin wall constructions or retaining internal space is a priority

Kooltherm K5 insulation boards offer an ideal solution for projects that require reliable thermal performance without altering internal layouts. They can be retrofitted externally to existing properties without disturbing occupants, improving energy efficiency while meeting building regulations for external wall applications.

Installation Tips For Kingspan Insulation Board

Kooltherm K5 External Wall boards should be installed in line with manufacturer guidance to achieve consistent results. Preparations begin with a clean substrate that is ready to support the insulation layer without gaps or moisture issues.

During installation, boards should be placed in a staggered pattern to limit thermal bridging and support stable adhesion. Fixings are added once the adhesive has set, with suitable patterns applied to secure each board firmly. This approach helps maintain alignment across the external wall and supports long-term performance.

Final steps involve applying a suitable basecoat with mesh to reinforce the surface before any thin coat or lightweight polymer modified renders are applied. These installation practices help the insulation materials work effectively across many wall types in both new and existing properties.

FAQs

1. Does Kooltherm K5 External Wall Board comply with UK Building Regulations?

Absolutely, Kingspan Kooltherm K5 meets all current building regulations for thermal performance and fire safety. The rigid thermoset phenolic insulation delivers exceptional thermal conductivity between 0.021-0.022 W/mK, making it one of the thinnest commonly available insulation boards that can achieve the required U-values for both new builds and retrofitting projects.

We at Licata always recommend checking your specific project requirements with building control. Our technical team can help calculate the exact external wall insulation board specifications you’ll need, whether you’re working on cavity walls, solid masonry walls, or extremely thin wall constructions where retaining internal space is crucial.

2. What thickness of Kooltherm K5 should I use for my external walls?

Choosing the right insulation thickness depends on your existing wall construction and the thermal performance you’re aiming for. For typical solid masonry walls on existing properties, we usually supply K5 external wall board between 60mm and 100mm to achieve U-values around 0.30 W/m²K, which keeps you compliant while saving space compared to other insulation materials.

If you’re working on refurbishment projects with cavity walls, the insulation boards might only need to be 40-60mm thick. Our team at Licata can run the thermal calculations for you, considering whether you’re using decorative thin coat render or traditional finishes to ensure the most highly effective insulation system.

3.How long does Kooltherm K5 External Wall Board last?

When installed properly as part of our complete external wall insulation systems, the rigid phenolic foam core in Kooltherm K5 external wall insulation will easily last 60 years or more. Kingspan backs their insulation products with a 10-year guarantee, and here at Licata, when our approved installers follow the manufacturer’s installation guidelines using metal screw mechanical fixings with correct adhesive and fibreglass mesh, we extend that with system warranties up to 25 years.

The key to maximising performance is proper installation with a protective render topcoat that shields the insulation core from UV light exposure. The rigid phenolic insulation doesn’t absorb moisture and maintains its thermal conductivity throughout its life, which is why we confidently specify it when existing properties need to be retrofitted externally to improve energy efficiency.

4.Can Kooltherm K5 be used with all types of render systems?

Yes, Kingspan Kooltherm K5 external wall board works brilliantly with any render you’d want to use, from traditional cement renders to modern thin coat renders and lightweight polymer modified renders. The phenolic insulation core faced with glass tissue on both sides provides maximum structural stability for whatever decorative thin coat system you choose.

The important thing is using the right basecoat adhesive and reinforcing mesh specified for your chosen finish. We stock all the compatible renders and mechanical fixings you need at Licata. Our technical specification composition sheets show exactly which products work together to create a superior external insulation system that qualifies for our extended warranties.

5.Does Kooltherm K5 require any special tools or techniques for installation?

Not really, the Kooltherm K5 external wall insulation board is quite straightforward to work with compared to other insulation materials. You can cut the 1200mm x 600mm boards with a standard fine-toothed saw. The lightweight insulation is easy to handle on site, gets mechanically fixed to your masonry walls with adhesive, then covered with basecoat and mesh before applying your finish.

We do strongly recommend using Licata approved installers who understand how to work with external insulation properly. They’ll know the manufacturer’s installation guidelines inside out, from preparing the substrate to dealing with details around window sills and ensuring the outer layer is applied correctly to avoid excess heat loss, which is essential for maintaining warranty coverage and delivering premium performance that improves energy efficiency.