Void formers and clay heave protection systems using our Dufaylite Clayboard honeycomb void former product

Clayboard is a unique, environmentally friendly void formers and foundation system to protect against clay heave. Clayboard has a 100% recycled and biodegradable paper honeycomb core set between lightweight polypropylene facings which have up to 70% recycled material content.

When dry, Clayboard® is strong enough to support the weight of wet concrete and steel reinforcement.

Water is introduced to the Clayboard® core once the concrete slab or beam is set, degrading the Clayboard® honeycomb centre which will ultimately lead to the creation of a void and clay heave protection.

This space will accommodate clay expansion without exerting undue pressure on the structure above. The resulting void continues to accommodate natural soil shrinkage and expansion.

Clay heave problems

The damage risk posed by natural shrinkable clay soils is well known to engineers and builders. Changes in the soil water content cause shrinkage or expansion which, if not properly accommodated, can result in structural damage. In these circumstance, clay heave protection is recommended.

Clay heave solutions saving costs

To remedy such damage can cost many thousands of pounds. It is essential therefore to choose an approved, reliable and proven clay heave protection system and void formers such as Clayboard® for all new buildings situated in clay areas.