It is important that water not be allowed to pool next to your foundations becuase excessive moisture ingress can cause cracking. While your minimum slab level will be determined by your civil engineer, it is generally preferable to raise the slab if your budget allows, because higher slabs tend to be better at repelling water and this may help prevent cracking. Your foundations will of course need to be properly designed and installed as well. Ideally, your structural slab level should sit above natural ground level and the level of the road or legal point of discharge by at least 150mm. Garages will normally sit lower than the main house by at least 150mm however it is possible to construct them with less of a level difference to improve accessibility for wheelchairs, prams and trolleys.
When your Architect Inspect inspector examines your slab at the pre slab stage, we examine the installation of the reinforcement and check that the concrete formwork is the correct depth and width. The slab must conform with your engineers drawings, Australian Standards AS2780, AS3600 and the National Construction Code.
To have your slab thoroughly checked by one of our professional building inspectors, contact us today.