Flooring Installation

Getting the subfloor right before any finished floor covering goes down

Whatever finished floor covering is chosen, its performance depends almost entirely on what's underneath it — a subfloor that's level, sound and appropriate for the flooring type — which is why subfloor preparation, not the flooring itself, is usually where problems trace back to.

Flooring installation starts with assessing the existing subfloor: whether it's a solid concrete floor or a suspended timber floor, whether it's genuinely level within the tolerance the new flooring needs, and whether it's dry, since laying flooring over a subfloor with residual moisture, particularly on a solid floor, can cause problems with adhesives, timber flooring, or moisture-sensitive coverings months after installation when the issue finally shows itself. Levelling compound is commonly used on solid floors to correct minor unevenness before flooring goes down, while a suspended timber floor may need boards checking, refixing or replacing where they've become loose or damaged before new flooring is laid over the top. Different flooring types have different subfloor and installation requirements: engineered and solid timber flooring generally needs a stable, dry subfloor and, depending on the product, may be fitted floating, glued or nailed down; tiling needs a rigid, properly prepared substrate since flex in the subfloor beneath tiles is a common cause of cracked grout or loosened tiles later; and vinyl or laminate flooring is more tolerant of minor subfloor imperfections but still needs a clean, level base to sit and perform properly. Getting the subfloor assessment right at the start avoids the situation, more common than it should be, where an otherwise good quality flooring product performs poorly simply because of what it was laid over.