Levelling a timber floor is where most self-levelling jobs go wrong. Wood expands, contracts and flexes — and a standard cement leveller poured straight onto it will crack. Here's what to use instead, and how to prepare the floor so it lasts.
The short answer
Use a flexible, fibre-reinforced compound — our go-to is Larsen SLC1550 Rapid Set Pro — or, for the most demanding timber floors, a two-part latex compound such as Larsen LLC206 NA. Never use a basic unmodified leveller on wood.
Why timber needs a special compound
Floorboards deflect underfoot and move with humidity. A rigid cement layer on a moving substrate fails at its weakest point — hairline cracks first, then debonding. Flexible compounds solve this two ways: added polymers tolerate movement, and fibre reinforcement knits the layer together. Two-part latex products go further, replacing most of the mixing water with a latex polymer for maximum flexibility — the traditional choice over old floorboards.
Option 1: Fibre-reinforced single-part (most jobs)
Larsen SLC1550 — fibre-reinforced, flexible, 3–50mm in one pour, walk-on in 2–4 hours. Suits rigid, well-fixed boarded floors and plywood overlays. It's the fast, economical route for most domestic timber floors. (Full details in our SLC1550 guide.)
Option 2: Two-part latex (lively or old floors)
Larsen LLC206 NA — protein-free two-part latex leveller, the specification-grade choice where boards have more movement, or where you want maximum insurance before tiling. Slightly more cost and mixing effort, significantly more tolerance.
How to prep a wooden floor for levelling
- Make it rigid. Screw down loose boards; replace damaged ones. If the floor still flexes, overlay with 6mm+ plywood or tile backer board, screwed at 200–300mm centres.
- Clean and prime. Vacuum thoroughly, then apply the appropriate primer — essential on timber to control suction and improve adhesion.
- Seal the gaps. Fill board joints or the compound will disappear through them.
- Pour and spread to your target depth (use our calculator for quantities), spiked-roller the surface, and keep the room ventilated but draught-free while it cures.
Can you tile onto a levelled wooden floor?
Yes — once cured, fix with a flexible C2 S1 adhesive (e.g. Larsen Fibreflex). The flexible system — compound, adhesive and grout all deformable — is what makes tiling on timber reliable.
Buying advice
Both compounds are stocked at our Coventry showroom for same-day collection, or delivered UK-wide — by the bag or on pallet deals for bigger jobs. Unsure which your floor needs? Call 0330 520 1804 with a photo and we'll tell you straight.
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