Floor Levelling in Maple Ridge and the Lower Mainland

Laminate, most vinyl plank and some engineered flooring are laid as floating floors. The planks lock together at their edges and the whole floor rests on the subfloor as one connected sheet. That works well, but only if the sheet is supported everywhere.

Over a dip, a plank spans the gap like a small bridge. Every step pushes it down into the hollow, it springs back up, and it bends at the click joint. After enough foot traffic the lock wears loose. The seam opens, the plank edges rise (installers call this peaking), or the joint pops and clicks underfoot. Over a hump, planks rock like a see-saw and the joints on either side take the strain. Rigid-core vinyl bridges small dips better than flexible plank, but its stiffer locking edge can snap where a softer one would bend.

A thicker underlay doesn't fix any of this. Underlay is soft, so over a dip it squashes more and the plank above it flexes more. Many manufacturers say plainly that underlay must not be used to level a subfloor, and damage caused by a subfloor outside the flatness spec is commonly excluded from product warranties.

Thinner, flexible vinyl fails differently. It follows the subfloor closely, so a ridge or dip shows through as a line or shadow on the surface, and it's most visible in low light from a window.

High spots are dealt with first. On concrete, that means a grinder with a diamond wheel and a vacuum attached to hold the dust down. On a wood subfloor, it usually means sanding or planing raised seams and panel edges, and screwing down anything that has lifted. In homes built before about 1990, old sheet vinyl and any old adhesive left on the subfloor can contain asbestos, so they should be tested before anyone grinds them.

Low spots are filled next. Self-levelling compound is a cement-based mix poured wet over a primed surface. It flows out and settles flat by itself, which is where the name comes from. Very shallow dips and feathered edges are often filled with a trowel-on patching compound instead, because a pourable compound needs some depth to flow properly.

The goal is a flat floor, not necessarily a level one. Because the compound settles level, pouring it across a whole room that slopes builds it up deep at the low end, which is rarely worth doing for flooring.

A wood subfloor needs a few extra steps. It has to be stiff and securely fastened. Gaps have to be sealed so the wet compound can't leak through to the ceiling below. The primer and compound have to be products made for use over wood, and some systems also call for a metal lath or mesh fastened down first. If the real cause is structural, such as a sagging joist or a subfloor that bounces, levelling compound won't fix it and can crack. That's better to find out before the new floor is down than after.