Claymaster 75mm

75mm Claymaster is an EPS compressible-fill material which can be used to prevent potential problems in foundations due to moisture movement in soils which contain a large proportion of mineral particles below 0.002mm (clay heave). The material can be used as permanent shuttering for cast in-situ reinforced concrete, reducing pressure on ground beams in piled foundations, and on the sides of trench fills.

Shrinkable clays are soils containing a large proportion of mineral particles of less than 0.002mm in diameter. This produces an extremely cohesive soil type when wet, but shrinks to a crumbly, crazed structure when dry. The expansion and contraction process during wet and dry periods is known as clay heave. This can cause severe problems with foundations.

Claymaster is a special low-density expanded polystyrene coloured in pink for ease of identification and is available to order in additional widths.

USE

• below concrete ground beams of a maximum depth of 600 mm
• in piled foundation construction
• at the vertical face of deep trench foundations
• to reduce the pressure exerted on the concrete by expansion of clay soils (clay heave) during the life of the structure.

PROPERTIES

• Claymaster provides a rapid, cost-effective solution to clay-heave problems, and no specialized trades or equipment are required
• With a normal ground-beam depth up to 600mm, the initial compression of the material during casting can be disregarded
• Claymaster is rot-proof and durable and will withstand the conditions encountered below ground. It will not degrade in the presence of high levels of ground water or precipitation
• Boards are normally rectangular and of uniform thickness, but special shapes are available to order including circular sections to fit around pile caps, and tapered boards
• The NHBC Standards, Chapter 4.2, building near trees, states that low-density compressible polystyrene is a suitable proprietary material to alleviate ground pressures on foundations in shrinkable soils

CERTIFICATION

Claymaster has been assessed by the British Board of Agrment according to Regulation A2, and found to reduce the effects of the expansion of clay soils which might impair the stability of a building. It has been approved for use under ground beams and against the sides of deep-trench fill foundations; Certificate number 90/2543.