Slab Defects in New Homes: Brisbane Handover Checklist

by | Oct 14, 2026 | Blog | 0 comments

Concrete slab defects are among the most overlooked problems in a new home, and many of them disappear from view once tiles, carpet or timber flooring go down. Brisbane buyers often assume that a passed council or certifier inspection means the slab underneath is sound. In practice, the handover walk-through is the last point where the concrete is clearly exposed, so it is the window to catch cracks, level changes and drainage faults before settlement. This guide covers what to check, how to tell normal shrinkage from genuine concern, and how to make sure the builder fixes what you find.

Table of Contents

Quick Takeaways

Key Insight Explanation
Check the slab before any floor finish goes down Once tiles, carpet or timber are laid, cracks and level changes are hidden, so handover is usually your last clear look.
Hairline shrinkage cracks are common, but movement is not Cracks that widen, step in height across the crack, or run through the perimeter need a structural opinion.
Measure levels with a long straightedge and spirit level Walk each room in two directions and mark high and low spots before the builder leaves site.
Ask for evidence of reinforcement and thickness Certifier sign-off confirms minimum compliance, not what was actually placed in the formwork.
Trace drainage and ponding around the perimeter Water sitting against the slab edge is an early warning of moisture problems that surface months later.
Log every defect with the responsible trade named A defect tied to a specific trade gets fixed faster than a vague line on a generic list.

Why Slab Defects Go Unnoticed at Handover

The slab is the first element built and the last one most buyers examine closely. By the time you collect the keys, the surface is usually covered in the living areas and bedrooms, so the only places you can see concrete are the garage, the laundry, the wet areas and sometimes the alfresco. Those are exactly the areas where a problem can be easiest to miss.

Inspector checking a bare concrete slab with a spirit level inside an unfinished Brisbane new home.

Most of the defects we see are not dramatic. They are small level changes, a hairline crack hidden behind a skirting board, or a floor that sounds hollow underfoot. None of these stop a house from being lived in on day one, which is why they often get signed off without a second thought.

What a certifier checks and what it does not

Private certifiers and council officers check that the work matches approved plans and meets minimum standards. They usually visit at set stages, so the slab may have been reviewed at the pour but not after plumbing, tiling or site drainage work changed the picture. A passed inspection tells you the house met the rules at that moment, not that every detail is right at handover.

Our view is simple: code is a minimum standard, not a quality standard. A slab can be compliant and still be out of level enough to cause door clearance problems within a year. Treat certifier paperwork as a starting point, not a reason to skip your own check.

Why handover is the last clear look

Once flooring goes in, the slab is effectively sealed. Movement and cracking continue to happen after handover, but you lose the ability to see them early. The practical answer is to inspect before any finish is laid, or to ask the builder to pause flooring installation until the slab has been reviewed.

Pro tip: If flooring is scheduled before your handover date, ask the builder to confirm in writing that the slab will be accessible for inspection before tiling or carpet starts.

Slab Cracking: Normal Shrinkage Versus Real Concern

Concrete shrinks as it cures and dries, so some cracking is expected in almost every new slab. Descom’s guidance on slab foundation issues lists slab cracking and shrinkage as one of the most common findings in new homes. The question for a buyer is not whether a crack exists, but whether it is behaving like shrinkage or like movement.

Normal shrinkage cracks are usually fine, narrow and stable. Movement cracks are different, and they tend to show a pattern over time. The difference matters because the response is different: one is recorded and monitored, the other goes to an engineer.

Hairline shrinkage cracks

A fine crack that is the same width along its length, sits flat on both sides and has not changed since the last visit is generally a shrinkage crack. We record its location, photograph it with a reference object for scale, and note it on the defect list so the builder cannot claim it was never raised. We do not recommend filling it cosmetically before the builder has responded, because that removes the evidence.

Cracks that signal movement

Be concerned when a crack shows an offset, where one side sits higher than the other. Also look for cracks that continue through the perimeter into brickwork, cracks that line up with door openings, and any crack that has widened since the start of the build. Insideout’s guidance on new construction foundations makes the same broader point: brand-new concrete can crack, develop moisture issues or show structural faults when soil, drainage or workmanship is not right.

A crack is not a defect just because it exists. It becomes a defect when it moves, lets water in, or stops the floor doing its job.

In practice, when we find a crack with offset, we flag it as requiring engineering assessment rather than leaving it as a cosmetic item. That single distinction often decides whether a builder fixes the problem properly or just paints over it.

Floor Levels and Flatness Across the Slab

A slab can be structurally sound and still be out of level. The problem shows up later as doors that drag, cupboards that do not close square and tiles that sit proud at one edge. For a handover, levels are one of the easiest things to measure and one of the most often skipped.

Flatness problems are rarely visible by eye. Standing water in the right light or a rolling ball can help you spot a trend, but neither gives you a measurement. You need a tool that shows the difference across a span.

How to check levels yourself at handover

Use a long straightedge, ideally around two metres, along with a spirit level. Walk each room in two directions, at right angles to each other, and mark high and low spots with painter’s tape. Pay attention to the points where a straightedge rocks or leaves a visible gap, because those are where the surface departs from flat.

Pro tip: Photograph each level variance with the straightedge and spirit level in the frame. A photo that shows the tool and the gap is far harder for a builder to dismiss than a written note.

Doors, windows and tiles as early warning signs

Doors that swing shut on their own, gaps at the top of door frames, and windows that stick are all signs that the floor or frame has shifted. Cracked tiles and uneven tile joints can point the same way, especially near the edges of the slab or in rooms where large-format tiles were laid. Note these signs even when the slab itself looks fine, because they are often the first symptoms a buyer notices later.

We have seen handovers where the tiler flagged a level problem before the builder did. Ask your tiler, if you can speak to them during handover, what they had to correct when laying the floor. Their answer is often more honest than the handover checklist.

Reinforcement, Thickness and Edge Details

Much of what determines a slab’s performance is buried before the concrete is poured. Thickness compliance and reinforcement placement both appear on the list of common issues in Descom’s slab foundation inspection guide. You cannot see steel once the slab is finished, so the real question is what evidence exists that the work was done correctly.

This is where many buyers feel helpless, but there is more to ask for than most people realise. Your handover documentation should show that the slab was checked at the right stage, and you are entitled to see it.

Close-up of a hairline crack on a bare concrete slab during a new build handover check.

Asking for pour and inspection records

Ask the builder for the engineer’s slab details, the pre-pour inspection record and the certifier’s sign-off for the slab. Slab defects are often first flagged at engineering or certifier inspections, which is why these records matter. If the builder cannot produce them, that is a finding in itself, and it should go on your defect list.

Keep the request specific. Asking for “the slab documents” tends to get you a folder of unrelated paperwork. Asking for the slab inspection record and the engineer’s slab detail gives you what you actually need.

Edge beams, perimeter and the brick junction

Check where the slab meets external brickwork, garage door openings and steps. Look for gaps, cracking or differential movement at these junctions, since they are the places where the slab and the structure can separate. A small, consistent gap that does not change is less worrying than a gap that is wider at one end than the other.

Edge details also control how water moves away from the house, which links directly to the drainage issues covered below. A poorly formed edge can trap water against the slab, even when the rest of the surface is level.

Drainage, Moisture and Ponding Around the Slab

Water is the biggest long-term threat to a concrete slab. Ponding against the perimeter, falls that run toward the house, and downpipes that discharge near the slab edge all add moisture where it should not be. Insideout’s guidance points to drainage and soil as common reasons new concrete develops problems, and the same principle applies to Brisbane’s wet summers.

Brisbane’s City Plan dwelling house code expects surface and roof water to be managed so that it does not seep, concentrate or pond in ways that cause trouble on neighbouring or nearby land. That is a planning requirement, but it is also a useful benchmark for what a finished site should look like at handover.

Falls and ponding after landscaping goes in

At handover, landscaping is often unfinished, so ponding may not show yet. Soil settles, paths are poured later and garden beds are formed after the slab is complete. Check the falls as they are now, and then check again after the landscaping and first heavy rain.

Pro tip: Book a short re-check within the first few weeks of living in the home, ideally after a heavy rain event. Water behaviour tells you more than a dry-day walk-through, and it gives you a documented point to raise with the builder.

Moisture signs inside the house

Watch for dampness along the bottom of internal walls, a musty smell in wet areas, or staining on the edges of floor coverings. These can point to moisture moving up through the slab or to a problem with the wet area membrane above it. Do not assume they are normal drying, particularly in the first year.

Plumbing Penetrations and Services Through the Slab

Drain lines, water pipes and conduits often run through or beneath the slab before it is poured. Once the concrete is in place, any fault in those services becomes hard to reach. That makes plumbing and penetration details part of the slab check, not a separate trade issue.

The most useful question is whether the penetrations were sealed and protected correctly. A pipe that passes through the slab without a proper seal can allow moisture and, in some cases, pests to travel up into the house.

Drain lines under the slab

Ask whether drain lines were pressure tested before the slab was poured, and whether the builder can provide the test record. Look for drainage traps and inspection points that are accessible without breaking the floor. If a drain blocks in the first year, an accessible inspection point saves a great deal of cutting and patching.

Penetrations and sealing details

Check the points where pipes or conduits rise through the slab into wet areas, the laundry and the kitchen. Each penetration should be sealed around its perimeter, and the seal should be intact. Gaps around penetrations are easy to fix at handover and expensive to fix once tiling is complete.

Comparing Three Ways to Check a Slab at Handover

Buyers usually have three options for checking a slab, and each one catches a different set of problems. The right choice depends on how much you know about construction and how much you want documented before you sign. The table below sets out how they compare in practice.

Approach What It Catches Where It Falls Short
Builder’s own walk-through Obvious finishing faults and items the builder already knows about The builder is checking their own work, and defects are often logged without the responsible trade or a clear measurement
Buyer’s visual check alone Visible cracks, marked surface damage and obvious door or window issues Levels, hidden drain faults and crack movement are easy to miss without measuring tools or experience
Independent inspection with photo-enhanced report and trade attribution Cracks, levels, drainage and penetrations, each recorded with photos and assigned to a responsible trade It is an additional cost, and it works best when booked before flooring goes down

In our experience, the difference between the approaches is less about how many defects are found and more about how they are documented. A defect that names the trade and includes a photo gets actioned faster than a line that says “slab cracked.” Our pre-handover inspections start from $550 including GST, and reports are typically available the same day, so the list can go to the builder while the site is still active.

What to Do When You Find a Slab Defect at Handover

Finding a slab defect at handover is common, and it does not automatically mean the house cannot be settled. What matters is how you record the defect, how you communicate it, and what you agree in writing before you sign. Do not treat a verbal assurance from the site supervisor as a fix.

Tablet with a blank defect report beside exposed slab reinforcement on a new home under construction.

Writing the defect list so it gets fixed

Each defect should have a location, a description, a photo with a scale reference, the responsible trade and a requested action. Vague entries like “floor issue, kitchen” are easy to close without fixing anything. Specific entries like “level variance of visible magnitude across the kitchen, responsible trade: concreter, requested action: grind or repair and re-check” leave less room for interpretation.

Keep a copy of the list and the builder’s response. If the builder marks an item as complete, re-check it before the next stage. If you are working with a conveyancer or lender, let them know about any open structural items before settlement.

When to bring in a structural engineer

Bring in a structural engineer when a crack shows offset, widens over time, runs through the perimeter or appears alongside door or window distortion. An engineer can assess whether the movement is ongoing and recommend a repair method. A builder’s repair is not an engineering assessment, and you should not accept it as one.

Queensland’s building regulator, the QBCC, is also a useful point of contact if a builder disputes a structural defect. Warranty and statutory protections differ for structural and cosmetic faults, so check the terms before you assume a repair is covered.

Frequently Asked Questions

Are hairline cracks in a new concrete slab normal?

Yes, fine hairline cracks are common in new slabs because concrete shrinks as it cures. The key is whether the crack is stable, flat on both sides and unchanged since your last visit. If it shows offset, widens or runs through the perimeter, it needs an engineering opinion.

Can I refuse handover if the slab has defects?

You can raise the defects in writing and ask for them to be rectified before settlement. Whether the house is ready for handover depends on the contract and the severity of the defects, so get advice on your specific contract before you refuse to sign. Keeping a clear, photographed defect list is the strongest position you can take.

Should I get a structural engineer or a building inspector?

A building inspector is the right first step for a full handover check, including levels, drainage, penetrations and finishing. A structural engineer is the right choice when cracks show movement or offset. Many buyers use both, starting with the inspector and bringing in an engineer only if a finding warrants it.

How soon after handover should I check the slab again?

A re-check within the first few weeks is sensible, especially after a heavy rain event. Landscaping, soil settlement and seasonal moisture can all reveal problems that were not visible on the day you took possession. Record the findings and send them to the builder in writing.

Do builder warranties cover slab defects?

Warranty coverage depends on the contract, the type of defect and the statutory protections that apply in Queensland. Structural defects and cosmetic faults are often treated differently, so read the terms carefully and confirm them with the builder and the QBCC. Do not assume that a defect is covered simply because it appeared after handover.

What does a pre-handover slab inspection cost?

Your GoInspect price depends on the inspection service, property type, size and location. Use the current online quote calculator for your property rather than relying on an old starting price. Builder and developer projects need a project-specific quote.

If you have dealt with slab cracking or levelling problems at your own handover, tell us in the comments how your builder responded and what you would do differently.

References