Claymaster is a compressible expanded polystyrene, specially manufactured within a critical density range.
It is Agrément approved and designed to alleviate the lateral force of ground movement on foundations. Claymaster does not compress significantly until loads exceed 20kN/m2. A load of 40kN/m2 is needed to produce 50% compression. Consequently its use is not recommended under ground floor slabs.
Claymaster is totally unaffected by water, and like Cellcore it can be used on sites where the foundations are below the water table. It is available in a range of thicknesses, that will compress to accommodate selected levels of predicted ground movement.
Dimensions Claymaster is produced in a standard size panel 2400mm long, by 1200mm wide, with thicknesses ranging from 50mm - 300mm. However, Cordek provide a made to measure service on length and width, with special shapes like circular sections cut to order.
Selection of Claymaster Lateral ground movement and void characteristics |
Shrinkage Potential |
Predicted Lateral movement NHBC recommended void |
Claymaster thickness for 'equivalent void' |
Low |
Zero |
Zero |
Medium |
25mm |
50mm |
High |
35mm |
75mm |
*Very High |
60mm |
100mm |
*This category is recognised by the BRE |
Deep Trenchfill is a traditional type of house foundation and where necassry Claymaster is used to protect the sides agains ground movement.
Due to more conomic piling methods, disposal cost of excavated material and stricter Health & Safety regulations, its use is declining. |