Laminate goes down quickly, which is exactly why it gets rushed. The planks themselves are forgiving. The subfloor, the acclimation and the expansion gap are not — and those three account for most of the floors that develop a problem in the first year.
The subfloor has to be flat, dry and clean
Flat is not the same as level. A floor can slope gently across a room and be fine; what laminate cannot tolerate is a dip or a hump over a short distance. The planks bridge the gap, the joint takes the load every time someone walks over it, and eventually the locking edge wears and the seam separates or starts to click.
Low spots get filled and high spots get ground down before anything else happens. Every screw head, staple, blob of old adhesive and lump of dried compound has to come off too — a single proud staple will telegraph through as a click underfoot forever.
Let it acclimate
Laminate expands and contracts with the humidity in the room. Planks delivered from a cold van into a heated house are not the size they will settle at. Leave the boxes flat in the room they are going into, for the time the manufacturer specifies, before opening them.
Skip this and the floor is installed at one size and then tries to become another — which is when you get buckling in the middle of summer or gaps opening in the middle of winter.
The expansion gap is not optional
A laminate floor floats. It is not fixed down, and it has to be able to move as a single sheet. That means a gap around the entire perimeter — walls, door frames, pipes, hearths, kitchen islands, everything — hidden afterwards by skirting or quarter round.
Butt it tight to the wall to save on trim and the floor has nowhere to go when it expands. It lifts in the middle of the room. This is the most common laminate failure and it is entirely avoidable.
Underlayment, and moisture from below
Underlayment does three things: it smooths out minor subfloor texture, it deadens the hollow sound laminate can have, and depending on type it acts as a moisture barrier.
That last one matters over concrete. Concrete releases moisture vapour for a long time, and a slab that feels dry to the hand can still be pushing moisture upward. Over a slab, or any below-grade room, the moisture barrier is the part you do not skip.
Things worth deciding before we start
Small choices that are easy now and awkward later:
- Which direction the planks run. Along the length of the room usually looks best; running them toward the main light source hides the seams.
- Whether doors need trimming — a floor adds height, and an interior door that used to clear may not.
- How the new floor meets the rooms next to it, and whether you want thresholds or a continuous run.
- Whether skirting comes off and goes back on, or whether quarter round covers the gap instead.
- Where the run starts, so you do not end up with a sliver-width plank along the most visible wall.
None of this is exotic — it is just the part of the job that happens before anything looks like progress. If a quote for a laminate floor does not mention the subfloor at all, that is worth asking about.