What We Fix
What We Fix
Sinking Floor Piers
Are my floors sinking because the piers have failed?
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. Most of the time, the piers are fine. The ground beneath them isn't. The soil has shifted, washed away, or dried out, and the piers have lost contact with what was holding them up.
The symptoms below will help you work out whether what you're seeing is sinking floor piers — and what's behind it.
What are the symptoms of sinking floor piers?
Your floors tell you when something is wrong. These are the most common signs of sinking floor piers.
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.
What are the signs of sinking floor piers?
What causes sinking floor piers?
The pier hasn’t broken. It’s lost contact with the bearer above it.
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.
What causes sinking floor piers?
How to fix sinking floor piers
Non-Invasive. Laser-Monitored. Guaranteed.
Lift Your Piers. Don’t Replace Them.
Nine times out of ten, the piers are fine. They haven't cracked, rotted, or failed. They're sitting on ground that moved out from under them. Replace the piers and the new ones go straight back onto the same ground — and you're back in the same boat.
So GeoPoly™ PSR30 resin injection tackles the issue at the root — the ground itself. Resin is injected through coin-sized holes, travels beneath each pier footing, fills the voids, and compacts the soil that failed. As it expands, the pier lifts back into contact with the bearer above. Slopes level out. Doors open easy again. Cracks close up again. Most jobs take 1–2 days — and because you're fixing the problem at the root, it's permanent.
Need your floor piers lifted? Learn about our floor pier repairs solution.
Structural Engineers · Licensed Builders · Skilled Technicians
Help & Advice
Articles to help you understand sinking floor piers and what to do next.
Floor LevellingWhat Are the Alternatives to Replacing Floor Piers?
If you've been quoted to have your floor piers replaced, it's worth pausing before that quote is signed. Most floor piers don't need replacing — they need re-supporting.
Floor LevellingLevelling a Sloping Floor
A sloping floor is easy to dismiss—until it gets worse. What starts as a slight tilt can turn into misaligned walls, sticking doors, or even structural instability.
FoundationCan a House Be Relevelled?
The short answer is yes. Most homeowners picture relevelling as something out of a renovation show — but in most cases the house never has to leave its address.
FoundationHow to Level-Check Your Own Foundation — A Homeowner's Guide
You don't need a structural engineer to know whether your floor has dropped. A spirit level, a tennis ball, and a tape measure will tell you in ten minutes whether your foundation is worth getting professionally checked.
ConcreteHow to Fix Sloping Concrete Floors in Your House
If your concrete floor has started to slope to one side, or sunk visibly in one area, the slab itself is almost never the problem. The ground beneath it has dropped.
Common questions about sinking floor piers
The questions homeowners ask us most often.
