Can laminate be fitted over floorboards?

Laminate can usually be fitted over existing floorboards, provided they are sound, flat, dry and firmly fixed. Loose or squeaky boards should be re-fixed first, and uneven or badly worn boards are often overboarded with plywood to give a flat base. Most manufacturers recommend laying laminate at right angles to the floorboards.

Timber floorboards are a common subfloor upstairs in most homes and downstairs in many older houses. Because laminate is a floating floor, it is not fixed to the boards, so it usually goes over them well, as long as a few things are checked first.

What to check before laying laminate over floorboards

Are the boards flat?

Laminate needs a flat base. Manufacturers set a flatness tolerance, typically measured as the maximum dip or hump under a straightedge of 1 or 2 metres, and the exact figure varies by product. Cupped, humped or worn boards can make the laminate flex, which strains the click joints and can cause gaps or a hollow feel underfoot.

Are they firmly fixed?

Loose boards move and creak, and that movement transfers through the laminate. Re-fix loose boards to the joists before laying anything. Screws are often used because they hold better than nails, but they must avoid any pipes and cables running under the floor. Checking with a detector, or lifting a board to look, is sensible.

Do they squeak?

A squeak under new laminate is very hard to fix later. Find and secure squeaky boards while they are still exposed.

Are there gaps or damaged boards?

Small gaps between boards are not usually a problem under laminate with a suitable underlay. Missing, split or rotten boards must be replaced, and large gaps or heavily worn boards are a reason to overboard.

Are they dry and well ventilated?

Any damp, rot or woodworm needs sorting first. On a ground floor with a suspended timber floor, the void underneath relies on airbricks for ventilation, so make sure they are clear and not blocked by the new floor or by soil outside.

Which way should laminate run over floorboards?

Most laminate manufacturers recommend laying the new planks at right angles (perpendicular) to the existing floorboards. That way each laminate plank spans several boards, which spreads the load and reduces the effect of any slight unevenness between them. If you would prefer the planks to run the other way, for example to follow the length of a room, overboarding first is usually the answer. Always check the instructions for your product.

When to overboard with plywood

If the boards are uneven, gappy, worn or you want the planks to run parallel with them, overboarding gives a flat, stable base and a better result. Plywood is commonly used, screwed down at regular intervals. Some manufacturers also allow other overlay boards, so follow their guidance on type and thickness.

Overboarding raises the floor height. Combined with the laminate and underlay, that can mean doors need trimming, thresholds need different trims and there may be a step up to adjoining rooms, all of which are worth planning for.

Which underlay to use over floorboards

You still need an underlay under laminate on floorboards, chosen to suit the product and the room. Fibreboard or foam underlays are common. On upstairs floors, an acoustic underlay helps reduce footfall noise in the rooms below.

On timber floors, a plastic damp-proof membrane is generally not recommended, because it can trap moisture against the boards. That is different from concrete floors, where a moisture barrier is normally needed. Some underlays come with a built-in vapour barrier designed for concrete, so check the manufacturer’s guidance before using one over timber. If the laminate has an underlay already attached, adding another may not be allowed.

Chipboard floors

Many modern homes have chipboard sheets rather than boards. The same checks apply: the sheets should be firmly fixed, flat, dry and free from swelling at the joints. Chipboard that has been wet, for example near a bathroom, can swell or soften and may need replacing before laminate goes down.

Finishing the edges

Laminate expands and contracts with temperature and humidity, so an expansion gap is left around the edges of the room, often 8 to 10 mm, though the manufacturer sets the exact figure. That gap is then covered either by fitting under the skirting, if the skirting is removed and refitted, or by adding scotia or beading along the existing skirting.

Common questions

Can laminate go straight onto floorboards without underlay?

Not usually. Unless the laminate has an underlay already attached, an underlay is needed to cushion the floor, absorb small irregularities and reduce noise.

Should I take up floorboards before laying laminate?

No. Sound floorboards make a good base. Taking them up is only needed if they are rotten or damaged, or there is a problem underneath to fix.

Does thicker laminate hide uneven floorboards?

Thicker laminate is a little more rigid, but it is not a substitute for a flat subfloor. See 8mm vs 12mm laminate for what thickness actually changes.

Next step

If you are unsure what condition your boards are in, request a home measure so the subfloor can be assessed, or ask for an estimate with a note of your floor type and a few photos. You can also read more about our laminate flooring service.