What to Look For After Your Slab Pour — The Complete Homeowner's Post-Pour Checklist

What "Post-Pour" Actually Means

Post-pour is the inspection stage AFTER the concrete has cured but BEFORE the frame goes up. Usually 3-14 days after the pour date.

It's the moment you can see: the finished slab surface (level, cracks, honeycombing); edge beam quality; whether the termite barrier survived the pour; whether the plumbing penetrations landed where they should; whether the slab dimensions match your plan; whether the set-downs (showers, garage) are the correct depth; whether the falls to drainage points work; and whether the concrete was cured properly (or left to bake in the sun).

Almost every defect at post-pour stage is either fixable now — while the slab is still exposed — or a red flag that needs engineer sign-off before you accept the work. Post-pour is the last moment to catch slab defects before framing hides them for the life of your home.

Why the Post-Pour Inspection Matters (More Than You Think)

1. Progress claim protection. Your builder issues an invoice at "slab down" — typically 15-20% of the contract price. Sign it and you've accepted the slab as compliant. QBCC dispute resolution gets very hard once payment is made.

2. Frame goes on top. Once the timber or steel frame is standing on your slab, you can't see the slab surface anymore. Any dimensional error, any set-down issue, any drainage fall gets buried.

3. Concrete defects compound. A hairline shrinkage crack today can become a moisture ingress path in year 5. Cracks in the edge beam can be structural. Honeycombing in the ribs weakens the load path. All of these are cheap to rectify NOW and expensive to fix later.

The 17-Category Framework I Use on Every Post-Pour

1. Slab Surface Finish & Level

The top of your slab becomes the floor of your home. Get it wrong here and every subsequent stage — tiles, timber floors, kitchen benches — becomes a nightmare.

The QBCC Standards & Tolerances Guide gives you three separate tests. A slab can pass one and fail another.

QBCC floor level + flatness tolerances: - Level (per room or area): max 10mm deviation from documented finished floor level - Level (over any 3-metre length): max 12mm deviation - Localised flatness: max 4mm under a 2-metre straight-edge - Overall building footprint: max 20mm deviation within 12 months of completion

What to look for: - Floor levels measured with laser or dumpy — record readings in each room and across each 3m length - Straight-edge test in multiple spots — anywhere over 4mm under a 2m straight-edge is a defect - Steel trowel finish achieved throughout (smooth and hard) - No trowel burns (dark patches where the surface was over-worked) - No excessive laitance (a weak, powdery top layer from water being added during finishing) - No re-tempering marks (water thrown on the surface to make finishing easier — this creates weak spots)

Red flag: More than 10mm level deviation in any room, more than 12mm over any 3-metre length, or more than 4mm under a 2m straight-edge. Any of these is a defect under the QBCC Standards & Tolerances Guide.

2. Cracks — What's Acceptable and What's Not

Every concrete slab cracks. The QBCC Standards & Tolerances Guide (drawing from AS 2870 Appendix C) classifies slab cracks in categories, and only Categories 3 and 4 are defects.

QBCC crack classification (all measured at their widest point): - Category 0 (Negligible): cracks under 0.3mm — hairline, not a defect - Category 1 (Very Slight): cracks under 1.0mm, slab reasonably level — not a defect - Category 2 (Slight): cracks under 2.0mm, slab noticeably curved or changed in level — not a defect - Category 3 (Moderate): cracks 2.0-15mm with significant curvature — defect - Category 4 (Severe): cracks over 15mm or significant structural movement — defect

What this means in practice: a thin crack in your new slab is normal. Don't panic. But you should still document every crack — width, length, location, pattern — because a Category 1 today can become a Category 3 in year 2 if the ground moves.

What to look for: - Measure crack widths with a crack gauge or credit card edge (0.5mm) for scale - Photograph every crack with a ruler in the frame - Note the PATTERN — random hairlines from shrinkage are expected; straight lines across the slab suggest settlement or bending - Cracks extending vertically down the edge beam = flag to engineer regardless of width - Cracks at re-entrant corners with no re-entrant steel above = flag to engineer regardless of width

Red flag: Any crack over 2mm wide (Category 3+) is a defect under QBCC. Get the engineer to inspect and certify before frame stage. Also flag any cracks — of any width — that appear at re-entrant corners or extend down the edge beam vertically, because pattern matters as much as width.

3. Edge Beam Quality

The edge beam is where your external walls will sit. Any defect here becomes a structural issue.

What to look for: Edge beam faces smooth and regular — no bulges (bulges = formwork wasn't braced enough); no exposed reinforcement (bars showing = zero cover = corrosion inevitable); no honeycombing (rocky, porous patches where concrete didn't fill — poor vibration during pour); clean corner details; edge beam depth measurable and matching plan; formwork removed cleanly — no timber cast into concrete.

Red flag: Honeycombing bigger than a $2 coin, OR any exposed reinforcing bar. Both require engineer assessment and repair before frame stage.

4. Termite Barrier Integrity (Post-Pour)

The termite barrier was installed pre-pour. But barriers get damaged during the pour, during formwork stripping, and by builders walking on them afterwards.

What to look for: - Physical barrier (Kordon / Termimesh) still visible and intact at all slab edges - Termite barrier not cut, torn, or missing at pipe penetrations - Barrier extends the full perimeter — no gaps at corners - Any penetrations added AFTER the pour are sealed with an approved termite-compliant sealant - Chemical barrier zones haven't been re-excavated or disturbed - Termite compliance certificate signed off and dated after pour (per AS 3660.1:2014) - 75mm inspection zone clear and visible around the accessible perimeter (AS 3660.1 minimum) — not built over, not landscaped away, so any termite mud tubes have a chance of being spotted

Red flag: Any visible gap in the termite barrier greater than 0.5mm, OR a slab edge already landscaped over with no 75mm inspection zone. Termites don't need much — a gap the width of a credit card is a superhighway.

5. Slab Dimensions & Set-Out

Basic sanity check: is the slab the size and shape it's meant to be?

What to look for: External dimensions measured and matching the foundation plan (measure diagonals too — equal for a rectangle); internal walls set out correctly; slab square (diagonals equal within 10mm); garage rebate size correct (typically 350mm × 15mm); alfresco slabs where they should be and right size; no missing set-downs; boundary setback confirmed against title (a legal requirement — measure from the closest property line).

Red flag: Diagonals more than 20mm out of square. Your frame will never sit right. This is a full re-set-out problem, not a "we'll fix it in framing" problem.

6. Step-Down Verification

Bathrooms, garages, and alfrescos have concrete "set-downs" — recessed areas that allow for tiles, waterproofing, or garage door tracks.

What to look for: Shower recess set-down typically 70mm (allows for waterproofing + tile screed); garage rebate 350mm wide × 15mm deep at the garage door; alfresco set-down at least 30mm below internal slab (falls away from house); bath and WC recesses correct depth; all set-downs consistent depth around the perimeter; set-down edges clean and squared.

Red flag: A shower set-down that's not 70mm deep. Your waterproofer will over-thickness their screed, which creates a lip at the shower door that trips everyone for 30 years.

7. Falls & Drainage

Water needs somewhere to go. Concrete surfaces should slope towards drains, not pool. AS 3740:2021 governs wet area waterproofing and falls.

Shower fall requirements per AS 3740: - Shower area with vertical separation (hob, step-down, screen or water stop): fall to waste 1:100 minimum - Shower area with NO separation (open shower): fall to waste 1:80 minimum - Floor waste generally: fall between 1:80 minimum and 1:50 maximum

What to look for: - Shower set-down has a fall to the drain that meets AS 3740 (measure with a level and tape; confirm on a hose test) - Bathroom floor has fall to a floor waste - Alfresco slab falls away from the house (typically 1:100 minimum) - Garage floor slopes toward the driveway (drainage away from the internal slab) - No visible ponding after a hose test (pour a bucket of water on the shower rebate — it should flow to the drain within seconds, not sit) - External perimeter graded to fall away from the slab (site drainage per AS 2870 Appendix B: minimum 50mm fall over the first metre)

Red flag: A shower rebate that ponds water when tested. This gets tiled over and becomes a leak, then a defect claim, then rot behind your wall linings.

8. Concrete Curing Evidence

Concrete gains strength through hydration — it needs moisture for 7-28 days. Cured concrete lasts. Dry-cured concrete is weak forever.

What to look for: Evidence of curing compound (a slightly waxy or dull surface film), OR wet curing (slab kept damp or covered with plastic/burlap for 7 days), OR curing blankets still on if within the window; no surface crazing (fine eggshell crack pattern from rapid drying); no dust when you rub the surface (dusting = weak surface from poor curing).

Red flag: A slab poured 3 days ago sitting in 34°C direct sun with no visible curing effort. The top 20mm is now permanently weakened.

9. Saw Cut Control Joints

Saw cuts direct WHERE the slab cracks — so cracks stay in straight, controlled lines instead of random patterns.

What to look for: Saw cuts at all locations on the engineer's drawings (typically re-entrant corners + every ~6m in large slabs); cut depth minimum 1/4 of slab thickness (typically 25-30mm on a 100mm top slab); cuts made within 8 hours of pour (4 hours if hot); cuts straight and clean; any cracks that have formed follow the saw cuts (a good sign).

Red flag: No saw cuts at all in a slab larger than 8m in any direction. Random cracking is now guaranteed.

10. Plumbing Penetrations & Conduits

Every pipe that came up through the slab needs to be in the right spot, correctly sleeved, and undamaged.

What to look for: All penetrations match the plumbing layout drawing; kitchen island conduits present and in position (measure from the wall — a common miss); waste pipes protrude the correct height (typically 100-150mm for a WC riser); water rough-in stubs in position; electrical conduits stubbed where required; all penetrations sleeved with closed-cell polyethylene lagging; no pipes cut down or capped incorrectly.

Red flag: A pipe in the wrong position (measured from a wall or corner). Fitting a fixture around a misplaced pipe usually means demo work.

11. Perimeter Drainage & Downpipes

What to look for: Downpipe positions marked or installed at plan locations; stormwater drainage points visible at each corner (or as designed); no stormwater pit or line damaged during the pour; perimeter ag-drain (if specified for reactive soils) visible and intact; silt trap / sediment fence still in place; no standing water against the slab edge.

Red flag: Stormwater pipes crushed or filled with concrete debris. This won't work in the first heavy rain and water will pond against your slab.

12. Post-Pour Damage

Between pour day and your inspection, the slab gets walked on, driven on, dropped on.

What to look for: No chunks broken off edges (from formwork stripping or wheelbarrow traffic); no deep tyre marks; no stains from oil, diesel, or paint; no damage from a framing crew starting before the concrete is fully cured; no damage from trades drilling test holes.

Red flag: Framing timber already stacked on the slab within 7 days of pour. Point loads from timber stacks on green concrete can crack the slab.

13. Efflorescence Check

Efflorescence is a white, powdery deposit that forms as moisture wicks through and evaporates.

What to look for: Some efflorescence on a young slab is normal (moisture still moving through — a good sign); heavy efflorescence localised in one spot may indicate a leak; efflorescence on the top surface may indicate the vapour barrier failed underneath; note the pattern — mostly at the perimeter or radiating from a penetration is a red flag.

Red flag: Concentrated efflorescence right at the base of a wall or plumbing penetration. Moisture is finding a path through the slab. Diagnose the source before framing.

14. Concrete Strength Documentation

The truck driver took cylinders on pour day. Those cylinders got tested. You should have the results.

What to ask for: - 7-day break test result (indicative strength — should be ~70-75% of the specified 28-day strength) - 28-day break test result (must meet or exceed the specified strength on your engineer's drawings — typically N25 or N32 for residential slabs; larger or engineered slabs may specify higher) - Sample cylinder identification numbers matching your pour docket - NATA-accredited laboratory report - Concrete supplier's batch report showing mix design

Red flag: No cylinder test results available, or 7-day results significantly below expected (e.g. under 60% of the specified 28-day strength). Do NOT accept the slab until 28-day results are in and meet the engineer's spec.

15. Slab Age Before Frame Load

Concrete gains strength over time. Loading it too early causes cracking.

Guide: Foot traffic OK after 24 hours; light materials + framing OK after 7 days; full framing load + trades traffic after 14 days; full design load (framing + roof) 28 days ideally.

Red flag: Framing crew booked to start on day 3 or 4 after pour. That's too early. Push back or wear the risk of early cracking.

16. Weather Protection During Cure

The weather in the first 7 days after pour matters as much as the pour itself.

What to check: If temperatures exceeded 32°C, were extra curing measures used (misting, shade cloth, blankets)? If heavy rain fell within 24 hours, is there evidence of surface damage or wash-out? If frost occurred within 24 hours (rare in SEQ but possible), strength may be compromised. If wind exceeded 30 km/h, rapid surface drying may have caused crazing.

Red flag: Heavy rain in the first 6 hours after pour plus visible surface pitting or wash-out. The top of the slab has lost strength permanently.

17. Documentation & Sign-Offs

The slab isn't officially "done" until the paperwork says so.

Must be on site or provided: concrete cylinder test results (7-day + 28-day); the supplier's batch report; termite compliance certificate (post-pour verification if required); the engineer's inspection report (many engineers do a post-pour walk before signing off); surveyor's set-out confirmation post-pour; plumbing rough-in sign-off from a licensed plumber; the builder's pour-day photos; the progress claim invoice matching the contract stage.

Red flag: No engineer sign-off, no cylinder tests available, and the builder asking you to pay the progress claim. Don't pay until the paperwork is complete.

The 30 Red Flags — If You See ANY of These, Call an Inspector Immediately

1. Level deviation over 10mm in any room OR over 12mm over any 3m length (QBCC S&T) 2. Localised flatness over 4mm under a 2m straight-edge (QBCC S&T) 3. Any crack over 2mm wide (QBCC Category 3+ defect) 4. Any crack — any width — that extends down the edge beam vertically 5. Any crack — any width — at a re-entrant corner with no re-entrant steel above 6. Visible exposed reinforcement bar anywhere on the slab 7. Honeycombing larger than a $2 coin 8. Slab out of square by more than 20mm across diagonals 9. Shower set-down not the design depth (typically 70mm) 10. Water ponding on shower recess when hose-tested (AS 3740 fail) 11. Alfresco slab not falling away from house 12. No fall from external perimeter (AS 2870 App B fail) 13. Damaged or missing termite barrier at any slab edge 14. Termite barrier cut around a pipe penetration and not resealed 15. No 75mm inspection zone around slab perimeter (AS 3660.1) 16. Any pipe penetration in the wrong position (measured from wall) 17. Kitchen island conduits missing 18. Waste pipes at wrong height 19. Stormwater pipes crushed or filled with debris 20. No saw cuts in a slab larger than 8m in any direction 21. Slab surface dusting when rubbed (weak surface from poor curing) 22. Heavy efflorescence localised at pipe penetrations or walls 23. Formwork timber left cast into concrete 24. Slab poured with no curing effort in 32°C+ weather 25. Rain damage visible on slab surface (wash-out, pitting) 26. Framing crew starting work within 7 days of pour 27. No cylinder test results provided 28. No engineer post-pour sign-off 29. Builder demanding slab-stage progress claim payment before docs are complete 30. Boundary setback measurement out of tolerance (legal issue)

Any 3+ = call an inspector. Any 10+ = don't sign the progress claim until fixed.

When to Book a Professional Inspection

I've just given you my complete checklist. You could try to do this yourself — some homeowners can. But here's what a professional inspector brings to a post-pour:

• A trained eye for the difference between shrinkage and structural cracking — the single most common misread by homeowners
• Level and falls measured with a laser — not eyeballed
• Dimensional verification against your plans — a tape measure and 15 minutes with your engineer's drawings
• Independence — I'm not your builder's mate. Your builder wants to invoice the progress claim; I want to protect your foundation
• An independent report with photos — evidence you can use in a QBCC dispute or to withhold progress payment lawfully
• Same-day delivery — the written report before you leave site
• A free 15-minute post-report call — I walk your builder or engineer through the report to resolve issues fast

When to book: as soon as the formwork is stripped (usually 3-5 days after pour), and BEFORE you sign the slab-down progress claim. Not after.

VG Inspect Post-Pour Pricing

• Standard home up to 220m²: $550 inc GST — same-day report
• Larger homes: custom quote — call 07 3180 8041
• Available: Monday–Friday across South East Queensland (Brisbane, Gold Coast, Sunshine Coast, Ipswich, Moreton Bay, Logan, Redlands, Scenic Rim)

Book your post-pour inspection: Call 07 3180 8041 or book online.

Where This Inspection Sits in Your Build

Independent stage inspections work best as a sequence — each one checks work that the next stage covers up for good. Here's the full pathway for a typical Queensland new-home build, and where the post-pour slab inspection fits:

1. Pre-Pour Slab Inspection — before the concrete truck arrives 2. Post-Pour Slab Inspection — you're reading this now 3. Frame Inspection — Timber Frame or Steel Frame, depending on how your home is built 4. Pre-Plaster (Lockup) Inspection — before the plasterboard hides the services 5. Practical Completion (PCI) Inspection — before you release your final payment

Previous: ← Pre-Pour Slab Inspection — Next: Frame Inspection (Timber or Steel →)

Booking the whole sequence with one independent inspector means every stage is checked against the last. Book your inspection or call 07 3180 8041.

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This checklist is general educational information based on Australian Standards and QBCC guidance. Your specific site may have engineered features, soil conditions, or wind classifications that fall outside this general framework. Your engineer's site-specific drawings and your building contract are the primary references for your build. This guide is not a substitute for a licensed inspection or legal advice.