Fitting methods & subfloor preparation

Before you start (both methods)

1. Acclimatise the flooring. Store packs flat, unopened, in the room where they'll be laid for at least 24 hours (48 hours if they've been somewhere cold), at 18–27°C. Keep the room in that range during fitting and for 24 hours afterwards.
2. Check every board before it goes down. Inspect for damage or shade differences in good daylight. Boards that have been fitted are generally treated as accepted.
3. Mix boards from several packs as you go, so the natural variation in the design is spread evenly across the room.
4. Turn underfloor heating off. Switch it off around 48 hours before, during, and for 48 hours after fitting, then bring it back up gradually (around 2°C a day). The floor surface should never exceed 27°C.

Subfloor preparation: what “good” looks like

Whatever you're laying, the subfloor must be sound, clean, dry, flat and free of contaminants (old adhesive, paint, grease, dust).

Concrete and screed floors

• Moisture: test with a hygrometer. For resilient floor coverings like LVT, BS 8203 calls for a relative humidity of 75% RH or below. New screeds take a long time to dry. As a rough rule, allow about a day per mm for the first 40mm, and longer beyond that, then always test rather than guess.
• Too damp? Apply a surface damp-proof membrane (usually a two-coat epoxy system) before smoothing.
• Flatness: aim for no more than about 3mm deviation under a 2m straightedge. Fill dips and grind down high spots.

Timber floorboards

• Fix any loose or squeaky boards and replace damaged ones. Make sure there's good ventilation underneath.
• For dryback: overlay with at least 5.5–6mm flooring-grade plywood, fixed at roughly 100mm centres around the edges and 150mm across the sheet with screws, ring-shank nails or divergent staples. Fill and sand the joints and fixings flush.
• For SPC click: boards must be flat and solid. If they're cupped or uneven, overlay with plywood first.

Existing floor coverings

• Remove carpet, underlay, and any loose or cushioned vinyl. Never lay over carpet.
• SPC click can often go over sound, well-bonded ceramic tiles, provided the grout lines are filled level so they can't show through or cause movement.

Fitting dryback (glue-down) LVT

Dryback LVT is a thin (typically 2–3mm) flexible vinyl that's fully bonded to the subfloor. Because it's so thin, anything under it can show through, so the preparation is the job.

1. Prime and smooth. Prime the subfloor, then apply a smoothing (levelling) compound to create a perfectly flat, smooth base, following the compound manufacturer's thickness and drying guidance. Once cured, lightly abrade, vacuum and prime again if the adhesive requires it.
2. Set out. Find the centre of the room and snap chalk lines. For herringbone, set out a straight, square centre line first. Accurate setting out is what makes a herringbone floor look right.
3. Adhesive. Use an LVT adhesive spread with the notched trowel the adhesive maker specifies (commonly an A1 or A2 notch). Respect the open time and lay into the adhesive at the right tack.
4. Lay and roll. Lay the tiles or planks tight, then roll thoroughly in both directions with a heavy (around 45–68kg) flooring roller, using a hand roller at edges and doorways.
5. Leave it to set. Keep foot traffic off for at least 24 hours, and wait at least 24 hours before wet cleaning or putting heavy furniture or appliances back.

Fitting SPC rigid core click flooring

SPC click boards lock together edge to edge and “float” on the subfloor, so no glue is needed. All of our click floors have underlay already attached.

1. Don't add another underlay. With attached underlay, an extra layer underneath can overload the joints and void the warranty. On concrete or screed, check the manufacturer's guidance on whether a damp-proof membrane (polythene sheet, overlapped and taped) is also required.
2. Leave expansion gaps. Leave around 5–8mm (or as the manufacturer specifies) around the perimeter and at pipes, door frames, thresholds and fixed objects. Cover the gap with skirting or beading, and don't fix trims through the floor.
3. Stagger the joints. Offset end joints by at least 300mm from row to row so they don't line up, which is stronger and looks natural.
4. Let it float. Don't fit kitchen units, islands or heavy fixed items on top of a floating floor. Fit the floor up to them. Very large areas or long runs may need expansion profiles, so check the product's maximum run length.
5. Undercut door frames so boards can slide underneath for a neat finish, rather than scribing around them.

Typical kit list