BEWI Claymaster 300mm Clay Heave Board

The 300mm BEWI Claymaster Insulation Board is a lightweight, compressible void-fill solution engineered to protect foundations from clay heave, soil shrinkage, and ground movement. This low-density, moisture-resistant expanded polystyrene material creates an effective protective barrier beneath ground structures.

BEWI Claymaster works by wrapping pile caps with a layer of pink EPS insulation, reducing stress on ground beams as surrounding clay expands and contracts seasonally.

This durable, easy-to-install board measures 2400mm x 1200mm and guards against clay heave and moisture-related foundation damage. Shrinkable clays contain fine mineral particles that create a cohesive soil when wet but crack and crumble when dry. The resulting expansion and contraction—known as clay heave—can seriously compromise building foundations.

BEWI Claymaster EPS insulation is supplied in 50mm, 75mm, and 100mm standard thicknesses, with 150mm, 200mm, and 300mm available to order for specific beam requirements.

Product specification

Brand: BEWI®

Model: 300mm Claymaster

Thickness: 300mm

Width: 1200mm

Length: 2400mm

Coverage: 2.88m2

Weight: 2.16kg

Dimensions: 2,400mm x 1,200mm x 300mm (other sizes available to suit beam dimensions)

Colour: Pink

Material: Expanded Polystyrene (EPS)

Profile: Compressible-fill clay eps board

Shipping method: Rigid Vehicle ǀ Courier

Applications: Piled Ground Beams ǀ Foundations

BBA Certified: Yes

Soil heave potential: Medium

Features: Against Clay Heave ǀ Foundations

Safe load: 20 kN/m2

Manufacturer: BEWI Claymaster®

Fail load: 40 kN/m2 produce 50% compression

BEWI Claymaster Highlights

1. Straightforward and quick installation with no specialist tools needed.
2. Naturally resistant to moisture and water damage.
3. Lightweight expanded polystyrene foam construction.
4. Reduces pressure exerted on ground beams.
5. Prevents lateral heave forces affecting foundations.
6. Provides lasting protection against clay heave and related foundation issues.
7. Distinctive pink colour aids identification during construction.
8. Protects against soil shrinkage and movement.
9. Requires no specialist trades or equipment.
10. Achieves A+ rating in the BRE Green Guide to Specification.
11. Available in multiple thickness options.
12. BBA Certified and meets NHBC standards.
13. Minimises lateral forces transferred to the building structure.

Application

1. Supporting concrete ground beams up to 600mm depth.
2. Installation in piled foundations.
3. Reinforcement of vertical faces in deep trench foundations.
4. Mitigating pressure from clay soil expansion (clay heave) to protect building integrity throughout its lifespan.

Certification

300mm BEWI has been assessed by the British Board of Agrement under Regulation A2. It has proven effective in controlling clay soil expansion that could threaten structural stability. The product is approved for use beneath ground beams and alongside deep-trench fill foundations. Certificate Number: 90/2543.

Benefits Of Expanded Polystyrene

1. Excellent Thermal Insulation: EPS insulation minimises heat loss, improving overall energy performance.
2. Lightweight: Low density ensures simple handling and installation whilst adding negligible weight to structures.
3. Moisture Resistance: Inherently water-resistant, preserving insulation effectiveness over the long term.
4. Versatile: Supplied in various forms to meet specific construction requirements.
5. Sound Dampening: Reduces sound transmission for a quieter interior environment.
6. Durable: Resists pests, mould, and fungal growth for reliable long-term performance.
7. Cost-Effective: Affordable material with strong thermal performance for budget-conscious builds.
8. Environmentally Friendly: Recyclable and often manufactured with recycled content, minimising environmental impact.
9. Easy Installation: Lightweight and simple to cut, enabling rapid and straightforward installation.

Info

Browse our BEWI range and filter by thickness or coverage on the left-hand side of the page. To discuss product suitability for your project or request a quantity discount quotation, call us on +4402038839057, email sales@insulationbee or use Live Chat - Lowest UK Claymaster Board Prices.