A WASTE glass lightweight aggregate has proved more cost-effective than standard void forming practices to counter the effects of ground heave on a site in Haslemere, Surrey.
Wilky Foundations Systems used Hasopor, a Norwegian material that can compress by up to 20%, beneath new ground beam foundations for a domestic building extension.
Managing director Neil Miller said: 'The engineer specified a void former and we didn't think we needed one so we compromised with this material. It was far more economical than traditional void forming techniques and easier to lay than polystyrene or cardboard.' Wilky poured the Hasopor after installing 27, 200mm diameter minipiles in mostly soft sand. The piles will support connecting ground beams separated from the aggregate by thin sheeting to prevent concrete fines from strengthening the glass.
The contractor finished the £23,000 job for client Kingshotts earlier this year.