Solutions
Sloping floor? The ground under it moved. Resin injected beneath the piers, stumps or slab lifts the floor back to level — no restumping, no floorboards up, done in a day.
- Free assessment · 1–2 day repair · 20-year warranty
- Structural Engineers · Licensed Builders · Skilled Technicians
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Sloping floor? The ground under it moved. Resin injected beneath the piers, stumps or slab lifts the floor back to level — no restumping, no floorboards up, done in a day.
- Free quote · 1–2 day repair · 20-year warranty
- Structural Engineers · Licensed Builders · Skilled Technicians
Solutions
Floor levelling — piers, stumps and slabs lifted, not replaced
Sloping floor? The ground under it moved. Resin injected beneath the piers, stumps or slab lifts the floor back to level — no restumping, no floorboards up, done in a day.
- Free structural assessment with a fixed-price quote
- Piers, stumps and concrete floors — most levelled in a single day
- 20-year product and workmanship warranty
Structural Engineers · Licensed Builders · Skilled Technicians
TrustpilotGoogleWhat is floor levelling?
Floor levelling brings a sloping floor back to level by fixing what's under it. Three kinds of floor sit on Australian homes: timber on brick piers (most of NSW and Queensland), timber on stumps (most of Victoria), and concrete slabs poured on the ground. All three slope for the same reason — the ground under them moved — and all three are levelled the same way: expanding resin injected beneath, lifting the floor back to level while a laser watches every millimetre.
Here's what 15,000+ jobs have taught us: the piers, the stumps and the concrete are almost never the problem. A concrete stump is a simple, solid post. A pier is a column of bricks. They hold for decades as long as the ground beneath them holds. When it shifts, they drop with it — and a brand-new one put onto the same ground does the same thing.
Your floors level out — and stay that way. Doors that have been sticking for months close properly again. The bounce underfoot stops. Gaps at the skirting boards close up. The kitchen bench sits flat. Done in a day or two, no floorboards up, no jacks, no digging.
When does a floor need levelling?
Floors move. Over time, most homes develop a creak here, a slight slope there. Some of it is normal settlement — the kind of thing you learn to live with.
But when the floor starts bouncing underfoot, doors begin to stick, and you can feel the slope getting worse — something else is going on. Place a ball on the floor; if it rolls, the floor isn't level. Look for gaps opening under the skirting, cracks in the gyprock near door frames, a table that always wobbles in the same spot.
That's when the ground under the floor has moved and hasn't finished. Which floor you have changes the words, not the fix — piers, stumps and concrete floors each get their own section below. Not sure which yours is? The free assessment takes the levels and tells you.
What are the signs of a sinking floor?
Your floors tell you when something is wrong. These are the signs that confirm the ground has moved — whatever the floor is sitting on.
Sloping or Uneven Floors
Place a ball on the floor. If it rolls away on its own, the floor isn’t level. Floor piers sink at different rates — one drops more than the next — and the floor follows. A table that wobbles, a cabinet door that swings open by itself — these are the everyday signs of piers that have moved.
Doors Sticking or Jamming
Doors in the middle of the house are usually the first to go. When piers sink unevenly, the floor tilts and the door frame twists out of square. The door catches the top of the frame, or scrapes the floor — sometimes both. If a door that used to close fine now needs a shove, the piers beneath that section of floor have more than likely moved.
Cracks Through the Middle of Walls
The outside walls sit on deep footings and rarely move. But the piers in the centre of the house often sit on shallow footings — and when the ground beneath them sinks, the floor bows in the middle. That downward pull cracks the internal walls above. If you’re seeing cracks through the centre walls of your home while the outside walls look fine, the piers in the middle have likely dropped.
Visible Pier Damage (Sub-Floor)
If you can see under your home, look at the piers. A gap between the top of the pier and the bearer above is the clearest sign — the pier has dropped and lost contact with the floor it was supporting. You’ll often find the gaps packed with shims or packers — that’s jack and pack, and it’s a sure sign someone has already noticed the movement.
Gaps Under Walls and Doors
When the floor drops, gaps open at the base of internal walls and under doors. Look at where the door meets the floor — if daylight shows through, or the gap is wider on one side than the other, the piers beneath have moved. The floor has dropped independently of the walls above it.
Bouncy Floors
When the ground beneath a pier sinks, the pier drops with it and loses contact with the bearer above. The bearer now has further to span, and it bows under the load — pulling the floor down with it. Walk across the room and the whole room seems to shake. Look at the skirting — if it moves up and down slightly when you walk past, the pier beneath that section has dropped.
Cracked Floor Slab or Tiles
Cracks running through floor tiles, or visible cracks in an exposed concrete floor. Concrete doesn’t bend — when the ground beneath it drops away, the slab spans an unsupported gap and cracks. Tree roots growing under slabs are a common culprit: when the tree is removed or the roots die back, the space they occupied becomes a void. If the cracks are getting wider, the void beneath is getting bigger.
A Hidden Plumbing Leak
A leaking pipe you can’t see. Water mains, sewer lines, and stormwater drains run beneath floor slabs — when one cracks or disconnects, water saturates the soil for months before anyone notices. The ground softens, loses its bearing capacity, and the slab sinks into it. If your water bill has crept up unexpectedly, a leak under the slab is worth investigating. Fix the water source first, or the floor will just sink again.
The Floor Bows in the Middle
A sloping floor tilts one way — one side has dropped. A bowing floor is different: the middle has gone down and the edges haven’t, so the room dips in a shallow dish. Put a ball down anywhere and it rolls to the centre, not to a wall. The outer edges of a slab sit on the footings and hold; the middle sits on fill, and when that fill settles the slab sags into the gap. Internal doors in that part of the house start jamming as the structure above takes the change.
What makes a floor sink?
The pier, the stump or the slab hasn’t failed. The ground beneath it has. Here’s why.
Soil Movement (Reactive Clay)
Reactive clay is the single biggest cause of sinking floor piers across Melbourne, Western Sydney, and South East Queensland. The soil swells when wet, shrinks when dry, and pulls away from the base of your piers. Each cycle leaves a little more gap — until the pier is sitting on nothing.
Previous Repairs
New steel piers installed in the same location as the old ones — without addressing the ground they’re sitting on. The original piers were likely fine. They hadn’t cracked or failed. The ground beneath them had moved. Replacing a pier that’s structurally sound doesn’t fix the problem — the new pier sits on the same unstable ground and sinks the same way.
Water Erosion
Burst pipes, leaking mains, broken bathroom drains, overflowing gutters — any of these can send water pooling beneath your home. Over time, the water erodes the soil around and beneath the piers, creating soft spots and voids. The pier sinks into the gap.
Tree Roots
Tree roots draw moisture out of the ground beneath your home. The soil dries, shrinks, and the pier drops — losing contact with the bearer above. Large trees close to the house are the most common culprit — but even hedges and garden beds with shallow roots can pull enough moisture to cause movement.
Changed Drainage
A new extension, a paved courtyard, altered stormwater — anything that changes where water goes around your home can redirect it under the house. The soil beneath the piers gets saturated, softens, and the piers sink. The drainage wasn’t wrong when the house was built. The conditions changed — and sinking floor piers follow.
The traditional ways of levelling a floor
Each one works in the right situation. But each treats the pier, the stump or the surface — not the ground that let them drop.
Restumping
Old stumps are dug out and replaced with new concrete or steel stumps. The house is jacked up, floorboards are removed, and the work takes weeks. It’s a legitimate fix when the stump itself has failed. But if the ground is the problem, new stumps sit on the same weak soil — and can sink the same way. The disruption is significant: most homeowners need to move out while the work happens.
Pier Replacement
Old brick or concrete piers are dug out and replaced with new steel or concrete piers. It works — but it’s a major job. The house has to be jacked up, floorboards or bearers cleared, and significant digging done beneath the home. Weeks of work, and the inhabitants often need to move out.
Jack-and-Pack
Floors are raised using hydraulic jacks, then wedges or timber pieces are fitted between piers and bearers to close the gap. It works as a short-term fix. The trade-off: the soil beneath the pier hasn’t changed. If the ground keeps moving, the packs shift and the floor drops again. Quick — but temporary.
Self-Levelling Cement Screed
A cement-based mixture is poured to even out dips and slopes in the floor surface. It works for concrete slab floors with minor unevenness. The limitation: it doesn’t fix the piers or the ground beneath them. If the piers are still sinking, the screed cracks and the floor slopes again.
Relaying the Floorboards
Floorboards are pulled up, bearers and joists adjusted or packed, and the boards relaid. It can flatten the floor surface — but the stumps are still sitting on the same ground. If the soil keeps moving, the floor drops again and the boards need relaying a second time. It treats the surface, not the cause.
Timber floors on piers
Most homes in NSW and Queensland sit on brick or concrete piers. The piers carry the full weight of your floors — bearers, joists, floorboards, internal walls, furniture, and the people walking across them. When the soil beneath a pier settles, compacts or washes away, the pier drops and everything above it follows. That's when the floor starts to slope. Leaking pipes, blocked stormwater, a long dry spell, vibration from a busy road and thirsty tree roots are the usual reasons the ground goes — what's making your house piers move walks through each one with what to look for.
Replace the piers and the new ones sit on the same unstable ground. Fix the ground, and the existing piers go back where they belong. GeoPoly™ PSR30 is injected beneath each pier footing through a hole the size of a coin, from above or below the floor — whichever suits your home. It fills the voids, compacts the soil and lifts the pier back into firm contact with the bearer above. From above, the hole goes through the floorboard directly over the pier, then down through the pier itself until the drill reaches the soil it stands on — so the resin arrives exactly under the footing, not beside it.
Timber floors on stumps — do you need restumping or reblocking?
Restumping works — when the stump itself has cracked, crumbled, or rotted through. That's a failed stump. Replace it. But most stumps Buildfix sees haven't failed at all. The concrete is sound. The stump is doing exactly what it was built to do. The ground underneath gave way.
Replace a good stump and the new one sits on the same weak soil. The floor drops again. Restumping — reblocking, if you're in Melbourne — treats the stump. Floor levelling treats the ground. No floorboards come up, no builders under the house for weeks, and a fraction of the cost.
Rotted timber stumps are the exception. A stump that's gone soft needs replacing, and the assessment says so plainly. The rest get lifted. If you've been quoted for restumping and you're wondering whether there's an alternative — this is it.
Floor levelling with GeoPoly™
Non-Invasive. Permanent. Guaranteed.
No Pier Replacement. No Digging. No Heavy Machinery.
Floor pier repairs with GeoPoly™ let you level your floors without enduring the expense and drawn-out process of traditional pier replacement. The resin requires only a small 1 cm drill hole for access and can be administered from either above or below the floor level — whichever suits your home.
GeoPoly™ resin is injected beneath and around your sinking piers. It expands to fill voids, compact weakened soil, and gradually lift each pier — and the floor above it — back to level. Real-time laser monitoring controls every millimetre of the lift.
Most floor pier repair jobs are finished in a single day. Your floors are level, your piers are sitting on stable ground, and you've avoided the cost and disruption of full pier replacement. Guaranteed for 20 years.
Wondering if your piers need replacing or just re-supporting? That's exactly what the free assessment answers.
Concrete floors inside the house
Concrete floor slabs sink too. It happens gradually — a slope you didn't notice until a door started sticking, a gap that opened at the skirting, a crack that appeared across the tiles. The slab hasn't broken. The ground beneath it has moved.
Most people assume the only fix is to jackhammer the floor, rip up the tiles, dig out the ground, recompact, repour and wait for it to cure. Weeks of work, house unliveable. The concrete almost never needs replacing. GeoPoly™ SJ120 goes in through coin-sized holes in the slab, fills the voids, compacts the soil and lifts the floor back to level — no tiles removed, no concrete broken, walked on the same day.
A sunken driveway, path or pool surround is a different job on a different page: slab lifting.
How much does floor levelling cost?
Timber floors on piers or stumps usually land between $4,000 and $8,000. The number of piers or stumps that have dropped, and how far, set the price. Concrete floors land between $4,000 and $14,000, because a slab takes more resin to lift. Either way it's a fraction of the cost of restumping or breaking up and repouring a slab.
The quote after the free assessment is fixed. Unlimited GeoPoly™ resin, no per-kilo charges, no allowances. The price you see is the price you pay. The full breakdown is in the floor levelling cost guide.
What to expect
How floor levelling works — from assessment to completion.
Step 1Free Structural Assessment
A Buildfix engineer inspects the subfloor, measures pier levels, and assesses soil conditions beneath the affected piers. If the ground has moved rather than the piers failing structurally, GeoPoly™ floor pier repairs are designed to stabilise and lift them without replacement.
Step 2Get Your Quote and Book
A complete quote package arrives — detailed drawings, repair method statement, and a fixed-price quote. The price you see is the price you pay. When you’re ready, book through the online portal and suitable dates are organised for the floor pier repairs.
Step 3GeoPoly™ Injection
Small injection points are drilled beside or beneath the sinking piers. GeoPoly™ resin is injected at depth, filling voids and compacting weakened soil beneath each pier. No digging, no pier removal.
Step 4Lift, Level, and Verify
Laser monitoring tracks every millimetre as the piers — and the floors above them — are gradually lifted back to level. The structural engineer confirms the floor pier repair results before the team leaves.
Step 5Receive Your Warranty
Your 20-year product and workmanship warranty arrives via email with the Completion Package — a job report covering the work, materials, and images.
See the difference
Actual GeoPoly™ floor levelling jobs — before and after.
Press the image for a closer look.Click on the image for a closer look.
Instant results.
Guaranteed to last.
The benefits of GeoPoly™ floor levelling.
Floor pier repairs with GeoPoly™ target the ground beneath each pier — stabilising the soil and lifting the pier back into contact with the bearer above. As the piers rise, you’ll notice floors evening out, doors closing properly, and the bounce underfoot stopping.
Ready for floors that feel solid again? Book your free assessment to get started.
Real homes. Real results.
15,000+ homes and structures repaired. Want to see real Buildfix floor levelling jobs? Browse a few below.
HomeownerBrighton East, VIC
Stumps Relevelled — No Restumping Needed
The concrete stumps were fine — the soil beneath them wasn’t. GeoPoly™ stabilised the ground and relevelled the floors in two days, saving this homeowner from a second full restumping job.
HomeownerStrathfield, NSW
Heritage Home Repaired Twice, Same Team
When new cracks appeared in this 150-year-old Strathfield home, the owner didn’t hesitate — they called Buildfix again. Buildfix had already fixed the front of the house years earlier. This time, the team tackled the rear.
HomeownerMosman, NSW
Sagging Timber Floor Raised Back to Level
A ball placed at one end of the living room rolled to the centre. The brick piers under this 1930s Mosman home had sunk on washed-out soil, and the floor was raised and relevelled in a day.
HomeownerO'Connor, ACT
New Kitchen Saved From a $50k Rebuild
A year after installing a new kitchen, it started pulling away from the wall. Local builders quoted $50,000 to fix it. Buildfix did it in four hours — without touching the kitchen.
HomeownerKings Park, NSW
Jack-and-Pack Failed — Deep-Lift Fixed It
A previous jack-and-pack had failed. The living room floor had sunk 40mm. Buildfix’s deep-lift injection fixed it permanently in a single day — without dismantling a thing.
HomeownerSouthport, QLD
Stumps Raised and Floors Levelled
Sloping floors, cracked tiles, and sunken stumps — this investment property needed to be tenant-ready fast. GeoPoly™ got it done at a fraction of the cost of restumping.
HomeownerPrestons, NSW
Floor Lifted 60mm — Renovation on Track
A broken pipe had eroded the soil beneath this property’s piers, sinking floors by up to 60mm. Buildfix stabilised and relevelled everything in two days — not the two weeks expected.
HomeownerSouth Brisbane, QLD
Queenslander Saved From Sinking in 2 Hours
A South Brisbane Queenslander with a 10-tonne water tank and a living area built in underneath was sinking. The cause was a leaking drain, and GeoPoly™ stabilised the whole house in 2 hours.
“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
“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
“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
“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.
