Engineered wood is more stable than solid timber because its plywood or multi-ply core resists the seasonal movement that makes solid boards cup and gap. It is not waterproof. The face is real timber and the core is real timber, and when either stays wet the floor behaves like any wood floor: it swells, moves and, if it stays wet long enough, comes apart. What matters is how much water, and for how long.
A spill wiped up within the hour
Nothing happens. The factory finish sheds water for long enough to grab a towel, and the micro-bevel or tight joints stop most of it reaching the core. Wipe it, dry the joins, and move on.
Water sitting for hours
A pot boiled over and left, a pet bowl knocked at breakfast and found at dinner, a window left open in a storm. Water works into the joints and the top layer of the core swells. You will see slightly raised edges along the board joins and perhaps a faint white bloom on the finish. Dry it out with towels and a fan over the next two days and most boards will settle back, though some edge swelling may stay.
Days of moisture
A leaking dishwasher, fridge line or shower tray behind a wall. This is where damage becomes permanent:
- Cupping. Boards curl up at the edges as the bottom of the core takes on more moisture than the finished face.
- Peaking and buckling. Swollen boards push against each other, and with no room to move they lift in a ridge.
- Delamination. The glue lines between the veneer and the core let go, and the face layer bubbles or peels.
- Mould. Under the boards and in the underlay, with the musty smell that goes with it.
What to do
- Find and stop the water first. Levelling the floor before fixing the leak wastes money.
- Lift the affected boards if the floor is floating; it is the fastest way to dry the subfloor and underlay. A glue-down floor needs a flooring contractor.
- Dry with fans and a dehumidifier for a week or more. Do not use heaters directly on the boards.
- Replace boards that have delaminated or cupped more than a couple of millimetres. Mildly cupped boards sometimes flatten as they dry.
Preventing it
Keep engineered timber out of bathrooms and laundries, use a mat under pet bowls and in front of the sink, fit a leak tray under the dishwasher, and lay a moisture barrier over any concrete slab. If you want a timber look in a wet area, use a waterproof hybrid floor instead. Read more in our guide on whether engineered timber flooring is waterproof.
Frequently asked questions
Often, if the water was there for less than a day or two and the floor is dried quickly. Once boards delaminate or cup badly they need replacing.
Sudden events such as a burst pipe are usually covered; slow leaks and lack of maintenance often are not. Photograph everything before you lift boards.
Slightly. The cross-laminated core moves less, but neither is suitable for wet areas.