Foundation and below DPC applications 

Choosing the right insulation for groundwork is crucial for the success and longevity of construction projects. Among the options available, Extruded Polystyrene (XPS), Expanded Polystyrene (EPS), PIR floor insulation, and Foamglas insulation are standout choices, each offering unique benefits for specific applications.

Whether you have a technical enquiry, need fast delivery (nationwide), or require a customised solution for your groundworks project, we’re here to assist you. Reach out to our support team on 0203 929 3999.

What type of insulation do I need for my groundworks project? 

1) Extruded Polystyrene (XPS) Insulation

Extruded Polystyrene insulation comes in different high compressive strength densities, moisture resistance, and thermal performance. It’s commonly used where moisture may be present, such as below-ground applications. 

Characteristics: Closed-cell structure, high R-value per inch, resistant to water absorption. 

Utilising XPS Insulation in Groundwork Projects:

Foundation insulation: It helps to maintain stable indoor temperatures, reduce heating and cooling costs, and prevent condensation and moisture-related issues in the foundation walls. It also provides added protection against frost heave in cold climates by keeping the soil surrounding the foundation warmer.  

Heavy Duty Flooring: XPS is ideal for new builds and renovations, boasting superior durability and moisture resistance. With low thermal conductivities (0.034 W/mK) and high compressive stress (300-700 kPa), it withstands heavy loads. Its closed-cell structure prevents water absorption and vapor passage, ensuring long-term performance. Easy handling and installation make it a reliable choice for various projects.

Basement walls: It improves the thermal performance of basement walls, reducing heat loss and minimising temperature variations between the basement and the rest of the house. It also helps to prevent moisture infiltration from the surrounding soil, keeping the basement dry and comfortable for occupants. Additionally, XPS insulation provides a continuous thermal barrier that helps to minimise thermal bridging through the wall assembly. 

Below-ground floors: Used beneath below-ground floors reduces heat loss through the floor, resulting in energy savings and improved thermal comfort indoors. It also helps to prevent moisture infiltration into the building, reducing the risk of mold growth, musty odors, and structural damage. Additionally, XPS insulation provides a stable and durable substrate for the concrete slab, enhancing its performance and longevity. 

Recommended products supplied by Wray-tech supplies: 

Kingspan GreenGuard is known for its high compressive strength and moisture resistance, Kingspan GreenGuard XPS insulation boards are commonly used for various applications, including groundworks, in the UK. 

British Gypsum Gyproc ThermaLine PLUS offers a convenient and cost-effective solution for upgrading the thermal performance of existing walls or constructing new walls with integrated insulation. It helps to create a more comfortable indoor environment while reducing heating costs and carbon emissions. 

Warmline insulated plasterboard offers a practical and versatile solution for insulating interior walls and ceilings while providing a smooth and seamless finish. It is suitable for both new construction and renovation projects where thermal performance and ease of installation are important considerations. 

Danosa extruded polystyrene boards provide effective thermal insulation, helping to reduce energy consumption, improve indoor comfort, and enhance building performance. They are durable, long-lasting, and resistant to moisture, making them suitable for use in both above-grade and below-grade applications. 

Knuaf Thermal Laminate offers an efficient solution for insulating interior walls and ceilings while providing a seamless finish. It is suitable for both new construction and renovation projects where thermal performance and ease of installation are important considerations. 

2) Expanded Polystyrene (EPS) Insulation

Expanded Polystyrene insulation is highly versatile and can be used in various above-ground applications, including walls, roofs, and floors. Its versatility stems from its ability to be molded into different shapes and sizes to fit specific project requirements. 

Characteristics: Lightweight, rigid, excellent thermal insulation properties, recyclable. 

Utilising EPS Insulation in Groundwork Projects: 

Road construction as lightweight fill material, especially in embankments, bridge approaches, and roadside slopes. It serves as a void filler to reduce the weight of the structure and improve stability while providing thermal insulation and moisture resistance. 

Landscaping for various purposes, such as creating artificial rocks, boulders, or retaining walls. It can also be used as lightweight fill material for landscape grading and contouring, providing stability and erosion control without adding excessive weight to the landscape features. 

Under-slab insulation due to its lightweight, compressive strength, and thermal insulation properties. It helps to minimise heat loss through the floor, maintain stable indoor temperatures, and reduce energy consumption for heating and cooling. 

Void formers in construction projects due to its lightweight, structural stability, and ease of installation. It provides temporary support for concrete slabs or foundations while minimizing the overall weight of the structure and conserving materials. EPS void formers are especially useful in areas with expansive soils or where settlement control is necessary. 

Recommended Products supplied by Wray-tech supplies: 

Jablite EPS insulation boards are lightweight, cost-effective, and offer good thermal insulation properties. They are commonly used in various construction projects, including road construction and landscaping. 

Springvale EPS boasts full certification, offering a lightweight and cost-effective solution for insulating a diverse range of ground-supported or suspended concrete ground floor constructions. 

EPS Frequently Asked Questions (coming soon)

3) Foamglas Insulation

Foamglas insulation is non-combustible and offers superior fire resistance compared to XPS and EPS. It does not contribute to flame spread or smoke development and has an A1 Euroclass fire rating, indicating the highest level of fire safety. Foamglas is an ideal choice for applications where fire resistance is paramount, such as high-rise buildings, tunnels, and areas with strict fire regulations. 

Characteristics: Cellular glass structure, load-bearing insulation, made from recycled glass (primarily vehicle windscreens), free of binders, produced from sand, dolomite, and lime. The production process excludes harmful blowing agents, high compressive strength without deformation, and resistance to water and water vapor. 

Utilising EPS Insulation in Groundwork Projects: 

Insulating foundations ensures consistent indoor temperatures, effectively lowering heating and cooling costs. Moreover, it acts as a barrier, averting condensation and moisture-related concerns within foundation walls. In colder climates, Foamglas offers an extra layer of defence against frost heave by preserving warmth in the soil around the foundation, safeguarding structural stability. 

It is also ideal for under-slab insulation in regions demanding sustainable and resilient solutions, prioritising environmental sustainability and enduring performance. 

Recommended Products supplied by Wray-tech supplies: 

Foamglas T4+ cellular glass insulation boards are known for their high compressive strength, moisture resistance, and sustainability. They are suitable for various projects, including foundation insulation and below-ground floors. 

Foamglas T3+ insulation boards offer similar characteristics to the T4+ variant, providing excellent thermal performance and resistance to water and vapor ingress. They are suitable for insulating foundation walls and below-ground floors in groundwork applications. 

Foamglas Frequently Asked Questions (coming soon)

Feel free to reach out to our support team on 0203 929 3999.

Alternatively, you can share details about your project by completing our project support form, and our experts will promptly follow up with you.

Wray-Tech Supplies