Of all the stage inspections VG Inspect conducts, the pre-pour slab inspection has the shortest window and the most permanent consequences if missed. Here's what you need to know.
What is the Pre-Pour Slab Inspection?
The pre-pour inspection occurs after your site has been prepared, your formwork is in place, your reinforcement steel is set, your termite barriers are installed, your vapour barrier is laid and your plumbing pipes are positioned — but before the concrete is poured.
This is the only opportunity to inspect the elements that will be permanently encased in concrete. Once the truck arrives, every element beneath the surface is inaccessible forever.
How Much Notice Do You Get?
Typically 24 to 48 hours. Sometimes less.
Your builder will notify you when the pour is scheduled, usually the day before. This is the moment to contact VG Inspect immediately. We prioritise pre-pour inspections above all other booking types and offer same-day and next-day availability specifically because of the time-critical nature of this stage.
Do not wait. Do not assume the pour will be delayed. Book the moment you receive notification.
What We Check
Reinforcement steel placement and concrete cover. The minimum distance from the outer edge of reinforcement bars to any internal surface is 20mm. To unprotected ground, the minimum is 40mm. We measure actual concrete cover at multiple points and document any insufficiency.
Bar chair spacing. Bar chairs support the reinforcement steel at the correct height above the substrate. Maximum spacing is 800mm centres. Wider spacing allows the steel to deflect between chairs, compromising concrete cover.
Splice lap lengths. Where reinforcement bars are overlapped rather than continuous, the overlap must meet minimum lengths: 500mm for N12 bars, 700mm for N16 bars. Short laps don't achieve the required structural connection.
Vapour barrier integrity. The vapour barrier must be continuous, with all cuts and penetrations taped using AS4200-compliant tape. Untaped cuts allow moisture vapour to transmit through the slab, creating long-term moisture issues in the finished floor.
Termite barrier continuity. The termite management system must be continuous around all penetrations through the slab, with termite collars on all pipes. Gaps in the system create entry points that void the termite barrier warranty.
Pipe penetration sealing. All pipes passing through the slab must be positioned so that concrete can fully surround them. Pipes touching reinforcement bars or waffle pods create voids in the concrete.
Site cleanliness. Vegetation, debris and formwork offcuts within the slab area can compromise concrete placement and cover.
Ready to book your inspection? A VG Inspect QBCC-licensed inspector attends every job.
Book an InspectionWhat Happens If Defects Are Found?
Defects found at pre-pour stage are the least expensive of any stage to rectify. Adjusting bar chair placement costs nothing. Retaping vapour barrier cuts costs minutes. Adding a termite collar to a missed penetration takes an hour.
The same defect found after pouring — through core sampling, physical investigation or, eventually, structural failure — costs orders of magnitude more.
A pre-pour inspection report that identifies defects before the pour gives your builder the information they need to rectify before the concrete is placed. A well-documented report means there is no ambiguity about what needs to be fixed.
Contact Us Immediately When You Get Your Pour Date
We mean this literally. The moment your builder tells you when the concrete is being poured, contact VG Inspect. Don't wait until the next business day. Don't assume we need more notice. We will do everything possible to attend before your pour proceeds.
The window for this inspection is too short and the consequences of missing it are too permanent to leave to chance.
