What to check before laying a wooden floor

Subfloor type, flatness, moisture readings, underfloor heating, acclimatising boards and clearing rooms: the survey a wood floor layer does before quoting.

5 min read

Before laying a wooden floor, check the subfloor: what it is, whether it is flat, firm and clean, and above all how dry it is. Take moisture readings in the slab or boards, ask about underfloor heating, measure the rooms, and look at door heights, thresholds and skirtings. Then agree with the client when the boards will be delivered to acclimatise, which rooms must be emptied and when other trades must have finished. Gaps, cupping and squeaks in a new wood floor can start with something the survey would have caught.

The subfloor

  • Concrete slab or screed: check its age, flatness with a straightedge, and dryness. New screeds hold a lot of water.
  • Timber boards or chipboard: check for movement, loose or squeaky boards, rot near walls, and the joist direction.
  • Existing floor covering: tiles, vinyl or old parquet change the method — remove, overlay or level first.
  • Flatness: dips and humps show through a floating floor and cause glue-down boards to hollow. Note the areas that need levelling.

Measuring moisture

Wood takes on and gives off moisture. Laid on a damp subfloor, boards swell and cup; laid in a very dry room, they shrink and gap later. Take readings with a suitable meter in several places, especially near outside walls, in kitchens and bathrooms, and on recent screeds. Write the readings down with the date and the room conditions. If the subfloor is too wet for the product chosen, say so and propose a date to check again rather than laying anyway.

Underfloor heating

Ask whether there is underfloor heating, what type, and whether it has been run and cooled as the manufacturer requires before a wood floor goes down. Check that the boards and adhesive chosen are suitable for it, and give the client the guidance on surface temperature.

Choosing the fitting method

The survey decides how the floor goes down: floating on an underlay, glued to the slab, or nailed or screwed to joists or battens. Each suits different subfloors, products and rooms. Explain to the client why you recommend one method, what it means for noise, comfort underfoot and future repairs, and how it changes the price and the time on site.

Doors, thresholds and levels

A new floor raises the finished level. Check whether doors will need trimming, how the new floor meets tiles, carpet or another room at thresholds, and the height at stairs and patio doors. Decide whether skirtings come off or the floor finishes against them with a bead. These details change the time on site and the look of the result.

Acclimatising the boards

Solid and engineered boards should rest in the rooms where they'll be laid, in their packs or as the manufacturer advises, so they adjust to the home's conditions. The heating should be on as it will be in normal use, and windows and doors fitted. Plan the delivery date with the client so the boards have time to settle before the fitting day.

Preparing the rooms

  1. Wet trades — plaster, screed, painting of ceilings — should be finished and dry.
  2. Rooms are emptied of furniture, or the client knows what you'll move and what you won't.
  3. Radiators to be removed or pipes to be sleeved are agreed with the plumber in advance.
  4. Parking, access for long boards and a place to cut, ideally outside or in a garage, are sorted.

Booking surveys with Book

On Book, each service has a name, a price and an optional description shown on your public page. Create a "Floor survey" service and open slots between jobs. Clients pick a slot and book with their name, email and phone, and can describe the rooms, the current floor and the boards they like in the optional note, which you read in your new-booking email. In the description, ask for the address and to have the rooms reachable. Once the quote is accepted, book the delivery check and the fitting days yourself from your calendar.

ServiceExample slotExample price
Floor survey and moisture check45 min€50
Fitting day8 h€320
Moisture re-check30 min€30

Durations and prices are examples: set your own. If the subfloor isn't dry enough and the fitting must move, reschedule from your bookings list and tell the client yourself, since Book doesn't email clients about changes. Book costs €5/month, everything included: unlimited services and bookings, no commission, no contract.

Can I lay wood on a new screed?
Only once it is dry enough for the product chosen. Take readings and wait if needed; laying early risks swelling and cupping.
How long should boards acclimatise?
Follow the manufacturer's guidance for the product, in the room where they'll be laid, with the heating on as normal.
Is the survey free?
That is your choice. A moisture check takes time and equipment, so some floor layers charge for it and deduct it from the job.

Guides for hardwood floor layers