* Delivery available on request - Please call before ordering Airtec 3.6N Foundation Block AERATED CONCRETE FOUNDATION BLOCKS Our 215mm Airtec Foundation blocks are designed as a lightweight, easy to lay, speedy and cost-effective alternative to traditional cavity foundation walls. The 215mm height block is offered as an alternative to our 140mm high type for builders wishing to use conventional coursing height blocks. Hand-holds are also provided at the ends of the blocks for easier, safe manual handling.