Floating Floor Repairs: Fixing Gaps, Lifting Boards and Separated Joints

Floating floors fail differently to nailed or glued ones. Nothing holds them down — the boards lock into each other and sit as one large sheet on top of an underlay. That’s what makes them quick to install, and it’s also why problems tend to show up as movement rather than damage.

Gaps opening between boards. A ridge running across the room where boards have lifted. Joints that have pulled apart and won’t click back. A hollow, flexing patch in one corner.

Almost all of it traces back to a handful of causes, and most of it is repairable without replacing the whole floor. Here’s what goes wrong and what the fix actually involves.

Why Floating Floors Move

A floating floor is designed to move. Timber-based products expand in humid weather and contract in dry weather, and because the floor isn’t fixed down, it moves as a single unit.

That movement is accounted for with an expansion gap — a deliberate space left around the entire perimeter, usually 10 to 15mm, hidden behind skirting or beading. The floor grows into that gap in summer and shrinks back in winter.

When the system works, you never notice. When something interferes with it, you get one of the problems below.

Gaps Between Boards

Gaps opening along the joints are the most common complaint, and there are three separate causes worth telling apart.

Seasonal contraction. The floor shrinks in dry weather and small gaps appear, then close again when humidity returns. If the gaps come and go with the seasons and are fairly even across the room, this is normal behaviour rather than a fault.

Failed locking joints. Where a gap stays open regardless of season, the click mechanism at that joint has likely worn or broken. Once one joint fails, the boards either side are no longer held, and the problem tends to spread outward.

The floor has crept. Floating floors can gradually migrate in one direction, usually along the length of the boards. This shows as gaps opening at one end of the room while the expansion gap at the other end closes up entirely. It’s often caused by heavy traffic in a consistent direction or by an underlay that doesn’t grip well.

The fix: seasonal gaps need nothing. A single failed joint can sometimes be re-seated by tapping the board back with a pull bar, and secured with adhesive in the joint if the mechanism won’t hold. Widespread gapping or a crept floor generally means lifting and relaying the affected area.

Lifting, Peaking and Buckling

This is the alarming one — a ridge running across the room where two boards have pushed up against each other and risen off the underlay.

It has a single underlying cause: the floor has expanded and had nowhere to go. With the perimeter blocked, the only direction left is up.

The usual culprits:

• No expansion gap, or too small a one. The most common installation error by a wide margin.
• Skirting or beading nailed through the floor. Trim should be fixed to the wall only. A single nail through the boards pins the floor and stops it moving.
• Something heavy pinning the floor. Built-in wardrobes, kitchen islands, and heavy bookcases installed on top of a floating floor prevent it from moving underneath them.
• Doorway thresholds fixed too tightly. Transition strips need to allow movement, not clamp the floor.
• Moisture. A leak, or moisture rising through a slab without a proper barrier, causes expansion well beyond the seasonal norm.

The fix: the pressure has to be released before anything else. Skirting comes off, the expansion gap is re-cut to the correct width around the perimeter, and any pinning fixings are removed. In many cases the floor settles back down within days once it can move again. Where boards have been permanently deformed by the buckling, those planks need replacing. If moisture caused it, the moisture source has to be dealt with first or it will simply happen again.

Separated Joints and Boards That Won’t Click Back

Sometimes a joint pulls apart and refuses to re-engage no matter how firmly you push it.

Usually the locking profile has been damaged — chipped during the original installation, worn by repeated movement, or broken when something heavy was dragged across it. A damaged click profile won’t hold again, and forcing it usually breaks more of it.

The fix: the joint needs either adhesive to hold it closed permanently, or the affected board needs replacing. Which one depends on where it sits. A joint in a low-traffic corner can often be glued and left. One in a main walkway will keep working itself apart.

Hollow, Bouncy or Noisy Spots

A patch of floor that flexes underfoot, sounds hollow, or clicks as you walk over it points downward rather than at the boards themselves.

The subfloor beneath has a dip, and the floating floor is bridging it. Every step flexes the boards down into that void and back up again. Over time, that repeated flexing is what breaks locking joints — so a hollow spot today is a separated joint in twelve months.

Other causes include underlay that has compressed or bunched, or debris left under the floor during installation.

The fix: this can’t be repaired from above. The boards over the affected area are lifted, the subfloor is levelled properly, fresh underlay goes down, and the boards are relaid. It’s more work than people hope for, but patching from the surface achieves nothing because the void remains.

Edge Swelling and Damaged Boards

Boards whose edges have swollen, darkened, or gone chalky have taken on water. Laminate is particularly vulnerable — its core is fibreboard, and once that swells the damage is permanent. Hybrid and vinyl-based products handle water far better but aren’t immune at the joints.

Individual damaged planks can be replaced. There are two approaches:

Unclicking from the wall. Skirting is removed and boards are unclicked in sequence back to the damaged one, then relaid. Cleanest result, more labour, and only practical where the damaged board is reasonably close to a wall.

Cutting out in place. The damaged plank is cut out of the middle of the floor and a replacement is trimmed and glued in. Faster, and the only option for a board in the middle of a large room. Done well it’s invisible; done badly it shows.

The practical difficulty is usually sourcing a match. Discontinued ranges, and colour that has shifted with UV exposure over several years, both make an exact match hard. This is why keeping a box of offcuts after installation is worth doing.

When Repair Isn’t the Answer

Some situations call for relaying rather than patching:

• Gapping or joint failure spread across most of the floor rather than isolated spots
• Widespread moisture damage through the boards
• A subfloor that was never properly levelled, with multiple hollow areas
• A floor installed without expansion gaps throughout, where the whole perimeter needs recutting anyway
• A thin, low-quality product where the locking mechanism is failing generally rather than at specific joints

The useful test: if the same problem is appearing in several unrelated places at once, the cause is systemic, and fixing individual symptoms will keep you busy without getting anywhere.

Preventing the Common Failures

Most floating floor problems are installation problems that surface later. If you’re having one laid:

• Make sure the subfloor is levelled properly first — this is the single biggest factor
• Insist on a correct expansion gap around the entire perimeter, including around pipes and doorframes
• Let the product acclimatise in the room before installation
• Check that skirting and beading are fixed to the wall, never through the boards
• Use the underlay the manufacturer specifies, not whatever’s cheapest
• Confirm a moisture barrier is used over concrete
• Keep a box of spare planks from the same batch

And once it’s down: use felt pads under furniture, lift heavy items rather than dragging them, wipe spills promptly, and avoid steam mops entirely.

Getting It Looked At

Floating floors give plenty of warning before they fail properly. A hollow spot, one gap that won’t close, a joint that’s started to lift — these are all early signals, and they’re much cheaper to deal with at that stage than after the movement has spread across the room.

If your floor has started doing something it didn’t used to, it’s worth having someone identify the cause rather than treating the symptom. For advice on flooring in Melbourne, our team is happy to take a look and tell you what’s actually going on.