How much does foundation repair cost?

Most foundation repairs range from $4,000 to $16,000, depending on the extent of the damage and the size of your property.

How long does the repair take?

Most foundation repairs are completed in just 1-2 days using our GeoPoly™ resin injection method.

What is GeoPoly™ resin injection?

GeoPoly™ is a high-strength expanding resin that we inject beneath your foundation. As it expands, it fills voids, compacts loose soil, and lifts your foundation back to level.

Will you need to dig up my yard?

No! We drill small holes (about 16mm diameter) through your slab or beside your footings, inject the resin, and patch the holes. No excavation required.

What does the 20-year warranty cover?

Our 20-year structural warranty covers the repair work we perform. If any issues arise with the repaired area due to workmanship or materials, we'll fix it at no additional cost.

Is the assessment really free?

Yes, 100% free with no obligation. Our structural engineer will inspect your property, explain the issues, and provide recommendations.

Can a sunken concrete floor be lifted back to level?

Yes, in most homes. GeoPoly™ resin is injected beneath the slab, fills the voids, and lifts the floor back towards level — with lasers tracking every millimetre. Most slabs come back to within a few millimetres. Your engineer measures the levels at the free assessment and tells you what's achievable before any work starts.

Do I need to replace the slab?

Rarely. The concrete usually hasn't failed — the ground under it has moved, and the slab has followed it down. Breaking the slab out and pouring a new one works, but it's weeks of mess and a new slab sitting on the same ground. Fix the ground and the slab you already have goes back where it was. The free assessment tells you which one you're looking at.

How long does floor relevelling take?

Most residential slabs are lifted in a few hours. There's no curing time — GeoPoly™ sets within minutes, so you walk on the floor straight away and the furniture goes back the same day. A larger home or a bigger drop can take two days.

What causes a concrete slab floor to sink?

The ground underneath moves. Reactive clay shrinking in dry weather is the biggest cause across South East Queensland, Melbourne, and Western Sydney — and in a raft or waffle slab home the floor is also the footing, so the whole slab settles with it. Poor compaction during construction, a leaking pipe washing soil out, tree roots hunting moisture, and plain settlement over decades do the rest. The concrete itself is usually fine.

Will my tiles crack when the floor is lifted?

The lift is gradual and laser-controlled, so the slab rises slowly and evenly. Tiles almost always come through untouched — the holes go through the grout joints, not the tiles, and are patched to match. If tiles are already cracked or drummy, your engineer flags it at the assessment.

Will the floor sink again?

GeoPoly™ doesn't just lift the slab — it fills the voids and compacts the soil beneath it into a base tougher than the original ground. If water caused the sinking (a leaking pipe, poor drainage), that gets fixed too or the soil washes out again — the plumbing check before the job is for exactly this. Every repair is backed by a 20-year product and workmanship warranty. If the foundation issue returns, so do we.

GeoPoly™ resin injected beneath a concrete floor slab to lift and level the floor — Buildfix technician working inside the home

Concrete Floor Levelling

Floor sinking? Lift it, level it, save it.

No tiles up, no new concrete, furniture stays put.

Structural Engineers · Licensed Builders · Skilled Technicians

Trustpilot

Google

15,000+Homes Repaired

20-YearStructural Warranty

1–2 DaysMost Repairs

Floor sinking? Lift it, level it, save it.

GeoPoly™ resin injected beneath the slab lifts your floor back into place — no tiles up, no new concrete, furniture stays put. Backed by a 20-year product and workmanship warranty.

Free quote · 1–2 day repair · 20-year warranty
Structural Engineers · Licensed Builders · Skilled Technicians

Concrete Floor Levelling

Floor sinking? Lift it, level it, save it.

GeoPoly™ resin injected beneath the slab lifts your floor back into place — no tiles up, no new concrete, furniture stays put. Backed by a 20-year product and workmanship warranty.

Free structural assessment with a fixed-price quote
Save the slab, and thousands compared to replacing it
Backed by a 20-year warranty

Structural Engineers · Licensed Builders · Skilled Technicians

15,000+Homes Repaired

20-YearStructural Warranty

1–2 DaysMost Repairs

GeoPoly™ resin injection — lift the floor from underneath.

Timelapse: a real slab lift

Fill the Voids. Firm the Ground. Lift the Slab.

Why the floor is sinking

A gap opening under the skirting. Tiles that sound hollow underfoot. A door that swung shut on its own until it didn't.

If your home sits on a raft or waffle slab, this is the slab settling into ground that's given way beneath it — reactive clay drying out, a leaking pipe washing soil away, fill that was never compacted. The concrete hasn't failed. It's followed the ground down.

How the slab comes back up

The old answers were to break the slab up and pour a new one, or screed a self-levelling compound over the top. Both work — and both leave the ground underneath exactly as it was.

GeoPoly™ goes the other way. Resin is injected through coin-sized holes in the slab, straight into the soil beneath. It expands, fills every void, firms up the soft ground, and with nowhere left to go, it lifts the slab. Lasers track every millimetre in real time.

What the day looks like

You'll see it as it happens — the gap under the skirting closing, the tiles sitting solid again, the door back on its latch. Most floors are lifted in a single day. Tiles stay down, furniture stays put, and the holes are patched before the team leaves. Backed by a 20-year product and workmanship warranty.

Not sure whether it's the slab or the ground? That's what the free assessment answers. Floor levels measured room by room, the cause named, and a fixed-price quote on the spot.

Structural Engineers · Licensed Builders · Skilled Technicians

Timelapse: a real slab lift

What to expect

Here’s how we lift a sunken slab floor, from first visit to warranty.

Buildfix structural engineer checking the slab edge of a home with laser level equipment

Step 1

Free Structural Assessment

One of our structural engineers measures floor levels room by room, checks the slab edge outside, and names what's moved underneath — reactive clay, a leaking pipe, fill that was never compacted. A GeoPoly™ repair plan is designed for your slab on the spot.

Buildfix quote package showing structural repair detail, quote cover page, and repair method statement

Step 2

Get Quote and Book

A complete quote package with drawings, method statement, and a fixed-price quote. The price you see is the price you pay. Book through the online portal when you're ready.

Buildfix technician injecting GeoPoly™ resin through a coin-sized hole in a home's floor slab

Step 3

GeoPoly™ Injection

Coin-sized holes are drilled through the slab at set points — through the grout joints where there are tiles. GeoPoly™ resin is injected straight into the ground beneath the concrete, filling the voids and firming up the soft soil so the slab has something solid to sit on.

Step 4

Lift, Level, and Verify

As the resin expands, the slab lifts. Lasers track every millimetre in real time, so the lift is controlled — not guessed. Gaps close, tiles stay down, and your engineer confirms the levels before the team leaves.

Step 5

Receive Your Warranty

The Completion Package arrives a few days after sign-off — a full report with images, invoice, and your 20-year product and workmanship warranty documentation.

See real slab lifts inside real homes.

Real Buildfix jobs — the gap under the skirting on the way in, closed on the way out. Same tiles, same day.

Press the image for a closer look.Click on the image for a closer look.

Gap under a skirting board on a tiled floor closed after the slab was lifted

Gap beneath a skirting board closed after an indoor slab lift

Sunken tiled floor at a doorway lifted back to the skirting line

Gap under a door frame on a timber floor closed after the slab was lifted

Cornice and ceiling gap above a kitchen cabinet closed after the slab was lifted

Gap under an internal door frame on a tiled floor closed after the slab was lifted

Diagonal wall crack below the cornice closed up after the slab was lifted back to level

Instant results.
Guaranteed to last.

The benefits of GeoPoly™ resin injection.

Every GeoPoly™ repair is backed by a 20-year product and workmanship warranty — the resin and the work. More than 15,000 of them have been issued in nearly 15 years. If the foundation issue returns, so do we.

Ready to get your floor checked?

Slab measured, cause named, fixed-price quote. It's free.

Structural Engineers · Licensed Builders · Skilled Technicians

Real homes. Real results

See how we’ve lifted sunken slabs back up — without breaking a tile.

Why choose Buildfix?

Buildfix brings structural engineers, licensed builders, skilled technicians, and the manufacturer together under one roof. For nearly 15 years, Buildfix has been delivering non-invasive structural repairs — saving homeowners the hassle and costs of traditional methods. What used to take weeks now takes just 1 to 2 days.

Why homeowners choose Buildfix:

Non-invasive technology. No tiles up. No slab broken out. No floors ripped up. You stay home while the work happens.

Guaranteed. Your repair is backed by a 20-year product and workmanship warranty. If the foundation issue returns, so do we.

One team, diagnosis to repair. Buildfix engineers assess your home and oversee the repair. Buildfix technicians carry it out.

Save the slab, and thousands compared to replacing it. Replacing a slab is weeks of work and a new slab on the same ground that moved. Fix the ground instead and the slab you already have goes back where it was — at a fixed price. If your job goes over, it's on us.

Structural Engineers · Licensed Builders · Skilled Technicians

Watch Video

Learn more about Buildfix and how we lift sinking slab floors — from underneath.

15,000+Homes Repaired

20-YearStructural Warranty

1–2 DaysMost Repairs

Structural Engineers · Licensed Builders · Skilled Technicians

Our technologies

Outside, the slab edge tells the same story.

Gaps at the edge beam and brickwork close as the slab lifts — the same kind of jobs, seen from outside.

Press the image for a closer look.Click on the image for a closer look.

Sunken brick wall corner at a fence line lifted back to level

Sunken tiled pool surround lifted back level with the pool coping

Gap between a sunken slab and brick wall measured, then closed after the lift

Gap between a sunken concrete slab and brick wall closed after the lift

Gap under brickwork at the slab edge closed after the slab was lifted

Gap between a sunken slab and an exterior door frame beside a hot water unit closed after the lift

Pool coping paver dropped below the slab, measured, then lifted back level

Cracked and sunken concrete driveway slab lifted back level outside a brick home

Don't take our word for it

Read what our customers are saying.

Questions?

Our team is here to answer any questions you may have Monday – Friday 8am to 5pm AEST. Give us a call on 1300 854 115.

Floor sinking? Lift it, level it, save it.