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.

How do I know if my house has subsidence?

Cracks that keep coming back after filling. Doors that used to close fine but now stick. Floors that slope when they didn’t before. Gaps opening between walls and ceilings. Any of these — especially if they’re getting worse — are signs the ground beneath your home may be moving. A structural engineer can confirm it in a single visit. The assessment is free.

What’s the most common cause of subsidence in Australia?

Reactive clay soil. It swells when wet, shrinks when dry, and moves your foundation with it. It’s the single biggest cause of house subsidence across Melbourne, Western Sydney, South East Queensland, and the ACT. Tree roots, poor drainage, and leaking pipes are also common triggers.

Can I just fill the cracks and see if they come back?

Filler treats the surface. If the foundation is still moving, the cracks will come back — same spots, sometimes wider. That’s the plasterer’s trap: fill, paint, repeat. If the cracks are caused by subsidence, the only permanent fix is stabilising the foundation itself.

How is subsidence repaired without digging?

GeoPoly™ resin is injected through small, coin-sized holes drilled around the problem areas. The resin expands beneath the footings, fills voids, compacts the soil, and lifts the foundation back towards level — which may close cracks and gaps in the process. No ripping up floors, no heavy machinery, no mess. Most jobs are done in 1–2 days at a fraction of the cost of traditional underpinning.

Will my foundation be relevelled?

When conditions allow, yes. Every situation is different — soil type, void size, and the type of footing all play into it. Sometimes relevelling isn’t recommended by the structural engineer — it’s always about the best outcome for your home. The engineer assesses all of this during the free inspection, so you’ll know exactly what’s achievable before any work starts.

Is the 20-year warranty transferable if I sell?

The 20-year product and workmanship warranty is attached to the property, not the owner. If you sell, it transfers to the new buyer automatically. If the subsidence returns in the repaired area, Buildfix comes back and makes it right — at no additional cost.

Foundation Subsidence

Worried it's subsidence? You can reverse it.

Find the cause, stabilise the ground beneath your home, and lift your foundation back into position — backed by a 20-year product and workmanship warranty.

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

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Foundation Subsidence

Worried it's subsidence? You can reverse it.

Find the cause, stabilise the ground beneath your home, and lift your foundation back into position — backed by a 20-year product and workmanship warranty.

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

Worried it's subsidence? You can reverse it.

Find the cause, stabilise the ground beneath your home, and lift your foundation back into position — backed by a 20-year product and workmanship warranty.

Free structural assessment with a fixed-price quote
Most foundations lifted and stabilised in just 1–2 days
Backed by a 20-year product and workmanship warranty

Structural Engineers · Licensed Builders · Skilled Technicians

15,000+Homes Repaired

20-YearStructural Warranty

1–2 DaysMost Repairs

Trustpilot

Google

Reverse the subsidence in a day or two. No digging.

Non-Invasive. Lifted & Stable. Guaranteed.

Find the Cause. Stabilise the Ground. Lift the Foundation.

Subsidence was one of those words no homeowner wanted to hear. The thought of your home sinking is bad enough. Then the potential structural issues. Then the hit to your home's value. The cost alone could knock hundreds of thousands off — some people would sell and take the loss rather than face it. Weeks of digging, council permits, certifiers, six-figure quotes. Those days are over.

Subsidence happens when the ground beneath your foundation softens, washes away, or hollows out. Reactive clay drying and shrinking. Tree roots drawing the moisture away. A leaking pipe washing soil out. Fill that was never properly compacted in the first place. Your house didn't change. The ground holding it up did. Patch the cracks above ground and they come back — same spots, sometimes wider.

GeoPoly™ resin injection is like keyhole surgery for your foundation. Small, coin-sized holes are drilled around the affected areas, then engineered resin is injected at depth beneath your home. The resin travels under high pressure, hardens within minutes — tougher than the original ground — and expands to fill voids and weak spots in the soil. As it expands, your foundation lifts back into position.

You'll notice cracks closing, floors levelling, gaps shrinking, and doors that were sticking working again. Lasers track every millimetre of the lift in real time, so it's controlled — not guessed at. The whole job typically takes one to two days, at a fraction of the cost of traditional concrete underpinning. When we're done, the drill holes are patched and your home left spotless. Backed by a 20-year product and workmanship warranty.

Not sure what's caused the subsidence — or how far it's spread? That's exactly what the free assessment is for.

Structural Engineers · Licensed Builders · Skilled Technicians

What to expect

Here’s how we lift and stabilise your home — from first visit to warranty.

Buildfix structural engineer assessing foundation subsidence with laser level equipment

Step 1

Free Structural Assessment

Our structural engineers assess the subsidence, identify the root cause, and design a tailored repair. Repair details — with photos, markings, and measurements — are created on-site using our mobile software, and the price can usually be explained there and then, so you know exactly where you stand.

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

Step 2

Get Quote and Book

You receive a complete quote package including detailed drawings, repair method statements, and a fixed-price quote — so you’ll know exactly what it’s going to cost. When you’re ready, book through our online portal (takes about 5 minutes) and we’ll organise suitable dates for the work.

Buildfix technician drilling small coin-sized access holes for GeoPoly™ injection

Step 3

Drill for Access

Small, coin-sized holes are drilled at precise intervals around the problem areas. These allow our injection pipes to reach the exact depths needed beneath your foundation.

Buildfix technicians injecting GeoPoly™ resin beneath foundations

Step 4

Inject, Lift, and Level

GeoPoly™ resin is injected through the access points. The resin expands to fill voids and weak spots, then lifts your foundation back into a stable, level position. Laser levelling equipment and digital sensors monitor every millimetre of movement in real time — so the lift is controlled, not estimated.

Patched drill holes after GeoPoly™ subsidence repair with clean site

Step 5

Patch and Clean Up

Once the foundation is stabilised and level, we patch the drill holes and clean up. Your home looks exactly as it did before we arrived — except now it’s on solid ground.

Step 6

Receive Your Warranty

A few days after sign-off, you’ll receive your Completion Package — a full report covering the work carried out, materials used, and images from the process. It includes your invoice with links to pay through our portal, and your 20-year warranty documentation. That’s your peace of mind, in writing.

See GeoPoly™ subsidence repair on real homes.

Real GeoPoly™ projects — foundations lifted and stabilised, controlled to the millimetre.

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

Brick wall subsidence crack before and after GeoPoly repair

Foundation subsidence before and after re-levelling

Subsidence crack in render before and after repair

Sunken foundation before and after GeoPoly injection

Subsidence damage to brickwork before and after repair

Foundation settlement before and after re-levelling

Brick wall separation from subsidence before and after repair

Subsidence crack repair before and after

Foundation subsidence before and after stabilisation

Brick wall subsidence before and after GeoPoly repair

Instant results.
Guaranteed to last.

The benefits of a GeoPoly™ subsidence repair.

GeoPoly™ resin is injected 2+ metres beneath your foundation and monitored in real time with laser levelling equipment and digital sensors. As the resin expands, it fills voids, compacts weakened ground, and lifts your foundation to a stable, level position — every millimetre of the lift controlled, not guessed at. You'll notice cracks closing, floors levelling, gaps shrinking, and doors that were sticking working again.

GeoPoly resin injection beneath brick house with laser levelling equipment monitoring precision

Ready to lift and stabilise your home?

Home levels checked, cause identified, fixed-price quote in your hand. Book an assessment — it's free.

Structural Engineers · Licensed Builders · Skilled Technicians

Real homes. Real results

See how we’ve helped homeowners fix their foundation subsidence.

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 trenches dug. No concrete piers. No weeks on a building site. 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 permanently fix foundation subsidence.

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.

Worried it's subsidence? You can reverse it.

Reverse the subsidence in a day or two. No digging.