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.

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?

GeoPoly™ resin is injected beneath the slab, fills the voids, and lifts the floor back towards level — monitored in real time with laser equipment. The slab can typically be relevelled to within a few millimetres. The structural engineer assesses exactly what's achievable during the free inspection, so you'll know before any work starts.

How long does concrete floor relevelling take?

Most residential floor slabs are relevelled in a few hours. Concrete relevelling — also known as slab jacking — uses expanding resin injected beneath the concrete, so there's no curing time and no waiting. Walk on the floor immediately after. Furniture goes back the same day.

What causes concrete floor slabs to sink?

The ground underneath moves. Reactive clay shrinking in dry weather is the single biggest cause across Melbourne, Western Sydney, and South East Queensland. Poor compaction during construction, plumbing leaks saturating the soil beneath the slab, tree root voids, and natural settlement over decades are also common. The concrete itself is usually fine — it's the support beneath it that's failed.

Will the floor just sink again after relevelling?

GeoPoly™ resin doesn't just lift the slab — it fills the voids and compacts the soil beneath it, creating a stable base that's tougher than the original ground. If a water issue caused the sinking (leaking pipe, poor drainage), that needs to be fixed too, or the soil will wash away again. Every repair is backed by a 20-year product and workmanship warranty. If the structural issue returns, so do we.

Sinking House Floors

Sinking floors? Your foundation's likely moving.

GeoPoly™ resin re-levels your slab and stabilises the foundation soil up to 2 metres beneath your home. The cause is fixed, the floor is level, and the structure is stable — backed by a 20-year warranty.

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

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Sinking House Floors

Sinking floors? Your foundation's likely moving.

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

Sinking floors? Your foundation's likely moving.

Free structural assessment with a fixed-price quote
Floor levelled and foundation stabilised — typically in a single day
Backed by a 20-year warranty

Structural Engineers · Licensed Builders · Skilled Technicians

15,000+Homes Repaired

20-YearStructural Warranty

1–2 DaysMost Repairs

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Re-level the floor. Stabilise the foundation.

Non-Invasive. Precision-Controlled. Guaranteed.

Foundation Stabilised. Floor Re-Levelled. Tiles Untouched.

If your indoor floors are dipping, sloping, or pulling away from skirting boards — and the cracks in your plasterboard walls are getting wider — the slab is moving. In many homes, especially those built on a raft slab or waffle slab, the floor slab is also the footing. When the ground beneath it shifts, the whole structure moves with it. Cracks inside, gaps outside on the edge beam, doors that won't close — these symptoms are connected. The floor isn't sinking on its own. The foundation is moving.

GeoPoly™ fixes the cause at the source. Resin is injected through small holes in the slab and travels up to 2 metres beneath your foundation. As it expands, it fills voids, compacts the weakened soil, and stabilises the ground that's been moving. The slab lifts under controlled laser monitoring — and the foundation underneath is reinforced at the same time. Two jobs, one repair.

Most jobs are finished in a single day. Your floors are level, your tiles are intact, and the foundation movement that was causing the structural damage is now stable. The cause is fixed — permanently. Guaranteed for 20 years.

Wondering whether your floor is moving on its own — or with the foundation underneath? That's what the free assessment answers. Your engineer maps the levels, identifies the cause, and tells you exactly what's moved beneath your home.

Structural Engineers · Licensed Builders · Skilled Technicians

What to expect

Here’s how we re-level your home’s sinking floors, from first visit to warranty.

Buildfix structural engineer assessing foundation movement with laser level equipment

Step 1

Free Structural Assessment

One of our structural engineers checks floor levels, inspects the slab, and identifies what's causing the sinking — whether it's soil settlement, washout, or compaction beneath the concrete. A tailored GeoPoly™ repair is designed 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 statements, and a fixed-price quote. Book through the online portal when you're ready.

Buildfix technicians injecting GeoPoly™ resin beneath indoor concrete slab to fill voids and lift the floor

Step 3

GeoPoly™ Injection

Small holes are drilled through the slab at precise intervals. GeoPoly™ resin is injected directly into the ground beneath the concrete — filling voids, compacting weakened soil, and creating a stable base for the slab to sit on.

Step 4

Lift, Level, and Verify

The slab is lifted gradually under laser-monitored precision while the resin continues to stabilise the soil up to 2 metres beneath the foundation. No tiles are removed. Your engineer confirms levels and verifies the foundation is stable 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 warranty documentation.

See GeoPoly™ floor re-levelling on real homes.

Actual GeoPoly™ projects where sinking floors are permanently re-levelled.

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

Gap beneath skirting board closed after indoor slab relevelling

Sunken brick wall foundation gap closed after slab lift

Gap under door frame on timber floor closed after slab relevelling

Sinking tiled floor at doorway relevelled back to skirting level

Cornice and ceiling gap above kitchen cabinet closed after slab lift

Sunken concrete slab at door threshold lifted back to brick wall

Sunken brick wall corner at fence line lifted back to level

Gap beneath skirting board on tiled floor closed after relevelling

Sunken concrete slab gap at brick wall measured and closed after lift

Sunken concrete slab gap at brick wall closed after relevelling

Instant results.
Guaranteed to last.

The benefits of GeoPoly™ floor and foundation repair.

GeoPoly™ resin doesn’t just lift the slab. It travels up to 2 metres beneath your foundation, filling voids and compacting weakened soil at the source of the movement. The floor returns to level, and the ground that’s been moving is reinforced. Two jobs, one repair.

GeoPoly resin injected up to 2 metres beneath concrete slab to stabilise foundation and re-level sinking floor

Ready to bring your floors back to level?

Floors measured, cause identified, fixed-price quote. It's free.

Structural Engineers · Licensed Builders · Skilled Technicians

Real homes. Real results

See how we’ve helped homeowners fix their sinking floors.

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 removed. No floors torn up. No structural rebuild. You can stay home while the work happens.

Guaranteed. Your repair is backed by a 20-year warranty. If the foundation moves again, we come back at no cost to you.

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

Save thousands — best pricing. All quotes fixed-price. No hidden charges. No surprise costs. If your job goes over, it's on us.

Structural Engineers · Licensed Builders · Skilled Technicians

Watch Video

Learn more about Buildfix and how we re-level sinking indoor floors — from underneath.

Structural Engineers · Licensed Builders · Skilled Technicians

“All of the Buildfix team have been easy to communicate with. Everyone was punctual and communicated arrival times well ahead of arrival.”

Scott HolmesMelbourne, VIC

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.

Sinking floors? Your foundation's likely moving.

Re-level the floor. Stabilise the foundation.