Timber Floor Installation

Installation is quoted per project rather than per square metre because the variables that drive the cost sit outside the floor area entirely. Subfloor type and condition, moisture status, the height available at doorways and thresholds, whether an existing covering is coming up, and which flooring system is going down all move the number more than the size of the room does. A quote given without seeing the subfloor is a guess.

Acclimatisation is the step most commonly skipped and the one most likely to cause failure. Timber arrives at the moisture content of wherever it has been stored, and it needs to reach equilibrium with the conditions of the room it is going into before it is fixed down. Install it too dry and it takes up moisture and expands, peaking at the joints. Install it too wet and it shrinks, opening gaps across the whole floor. On the Peninsula, with genuine seasonal humidity swings, this matters.

That means the timber sits in the space, unwrapped and stacked to allow air movement, for a period determined by the product and the conditions rather than by the schedule. It also means the space needs to be at something like its normal operating temperature and humidity during that period — acclimatising boards in an unheated shell that will later be a heated living room achieves nothing useful.

Subfloor moisture has to be established before anything is ordered. Over a concrete slab, that means testing rather than assuming, because a slab holds construction moisture far longer than most programmes allow for and will wick ground moisture indefinitely if the vapour barrier beneath it was compromised. Over a timber subfloor it means pin-type readings and an assessment of the ventilation and clearance underneath. Above 14 to 16 per cent, nothing goes down.

Flatness is the other pre-condition. A subfloor that is out of level beyond the tolerance of the flooring system produces a floor that flexes, creaks and eventually fails at the joints, and no amount of care during installation compensates for it. Where the substrate needs levelling, that is its own line item and its own work, and it happens before the flooring arrives rather than being discovered on the day.

The fixing method follows from the substrate and the product. Solid tongue-and-groove over joists is secret-nailed. Solid or engineered over a slab is generally direct-stick with the appropriate adhesive and moisture barrier. Engineered can also be floated over an underlay, which is faster and cheaper and produces a different feel underfoot — slightly hollower, more acoustically live. Each has a place and we will explain the trade-offs rather than defaulting to whichever is quickest.

Floating floors need their expansion gap and it is the most commonly botched detail in the trade. The floor has to be free to move at every perimeter, which means a gap at every wall, at every fixed vertical, and at doorways where the floor passes into another space. Laid hard against a skirting or with the gap later filled with sealant, a floating floor has nowhere to go when humidity rises and it peaks at the joints. That is not repairable by refinishing.

Finishing is a separate decision from installation. Pre-finished board arrives coated and is walkable immediately, which suits a tight programme, but the joints between boards are individually sealed and micro-bevelled rather than continuous. Raw board sanded and coated in place gives a continuous monolithic surface with no bevels, which looks better and takes several more days. On a job with other trades still to come through, the sequencing matters.

Board width is worth deciding deliberately rather than by catalogue. A wide plank at 180 or 220 millimetres reads calmer and more contemporary and is what most current Peninsula rebuilds specify, but a wide board moves substantially more across its width than a narrow strip, which makes acclimatisation and substrate moisture more consequential rather than less. Narrow strip at 65 to 85 millimetres is more forgiving in a variable environment and more in keeping with a period house. Neither is simply better.

Solid or engineered is usually decided by the substrate rather than by preference. Solid tongue-and-groove over joists gives you the most sands across the life of the floor and is the better long-term proposition where the subfloor allows it. Engineered is more dimensionally stable, handles a concrete slab and underfloor heating far better, and gives you wide boards without the movement risk — at the cost of a finite wear layer that caps how many times it can ever be refinished.