The base stage or slab stage inspection is the most important inspection during construction because the entire load of the house sits on the slab. That is, a house is only as good as the base upon which it is built!
Many new homes are now being constructed on concrete slabs. If the new concrete slab upon which your new home has been constructed fails (e.g. moves, heaves or settles), it can cause major structural defects (e.g. cracking in external walls, cracking in internal walls, cornice and ceilings, cracking in floor tiles and wall tiles and sticking and jamming of windows and doors etc.) not to mention all of the stress and inconvenience that goes along with trying to get the defective works rectified by your builder.
Arranging for the formwork and other preliminary works (e.g. the vapour barrier, the boxing and steel reinforcement etc.) to be thoroughly inspected and reported on by an independent building inspector, before the concrete for the slab is poured and finished, is therefore strongly recommended.
The items that need to be thoroughly checked before a concrete slab is poured and finished include (but are not limited to) the following:
- All trenches are straight, square, clean, and the correct width and depth – compliant with the relevant engineers drawings and specifications.
- The reinforcement placed in the trenches and in the boxed areas is the correct size, is adequately lapped and adequately tied together – compliant with the relevant engineers drawings and specifications.
- The trench mesh and steel reinforcing bars are adequately supported off the ground using bar chairs.
- The formwork is level and square and the size of the boxed area accords with the relevant floor plan.
- The vapour barrier has been fully and properly installed. It is very important to make sure that the vapor barrier has not been torn or punctured.
- The termite barrier (if required) has been correctly installed.
- All service pipe penetrations have been adequately sealed.
- The steel reinforcement is not too close to the boxing boards – to avoid steel reinforcement sticking out from the side of the concrete slab and being exposed to the weather after the boxing boards have been removed from the sides of the finished slab.
After the concrete slab is poured and finished, it is also very important that the following items are thoroughly checked:
- The slab is straight, square and level. Highly accurate laser measuring tools need to be used on site to check that the slab is level (i.e. within tolerance).
- The size and shape of the slab accords with the relevant floor plan
- The slab has been fully and properly completed (e.g. there is no steel reinforcement protruding out of the side of the slab).
- The slab has not been damaged and there are no serious cracks in the slab.
Finalinspect can complete a thorough and independent inspection of the formwork for your slab (i.e. the preparation works before the concrete is poured) and then inspect the finished slab, and prepare a detailed typed report for you that is ready to hand directly to your builder.
We ensure that the base has been completed compliant with the relevant Australian Standards, the Building Code of Australia (BCA) and the relevant engineer’s drawings and specifications.
To arrange an inspection, please call us now on 0408 132 152