A site survey confirms that the building is ready for wood floor installation. Work through this checklist before delivery arrives — it prevents costly callbacks and protects your warranty.
Pre-Installation Site Conditions
- Check that all gutters and downpipes drain water clear of the building.
- Inspect all damp-proof courses and confirm they are intact. Do not install solid hardwood flooring below the soil line.
- All wet trades — plastering, tiling and painting — must finish their work before installation begins.
- Switch on central heating, air conditioning and ventilation at least three to five days before delivery.
- Lay driveways and side walks before the flooring goes in, where possible.
- Enclose the building fully — roof, doors and windows must be in place and weathertight before delivery.
Subfloor and Crawl Space Requirements
- A new concrete slab must be flat, meet your specification, and reach 3% moisture content. Install a damp-proof membrane before laying any flooring.
- Use 18mm plywood as the preferred subfloor — this lets you secret-nail with a Portanailer.
- You can also bond the floor with an elastic polyurethane adhesive such as Sika T52, especially over dry concrete.
- Keep the subfloor flat and level. You can also install over joists or existing floorboards.
- Check all internal pipework — washing machines, dishwashers — for leaks before you start.
- Seal all external doors and windows properly and confirm nearby areas are dry.
- Lay 6mm black polythene over exposed soil in any crawl space under the ground floor.
- Provide cross-flow ventilation below suspended ground floor joists. Vent openings must equal 1.5% of the crawl space area — for example, a 100m² crawl space needs 1.5m² of ventilation.
- A 100m² crawl space draws approximately 70 litres of water every 24 hours from the soil and sends it into the building. Good ventilation counters this.
- The moisture content of the wooden subfloor must sit no more than 2–3% above the moisture content of the hardwood floor you plan to lay.
- Maintain temperature at 15–25°C and relative humidity at 35–50% inside the building before and during installation.
Installer and Owner Responsibilities
- Solid hardwood floors are natural products. Expect a grading and manufacturing tolerance of 5%.
- Inspect every board before installation. The installer or owner accepts full responsibility for product quality once installation begins.
- Confirm that the job-site environment and subfloor meet all requirements before you start — do not rely on a visual check alone.
- Store all flooring in the correct conditions before installation.
- The owner is responsible for ordering the correct grade, species, finish and quantity.
- Work from three or four cartons at a time to achieve a natural, even appearance across the floor.
- Cut out or hold back boards with obvious defects. Use them inside cupboards or discard them.
- Use stain, filler or putty stick for minor corrections — this is standard practice.
- Add 5% to your square meterage for cutting waste before placing your order.
Acclimatising Your New Floor
Acclimatisation allows the timber to adjust its moisture content to match everyday conditions inside the building. Aim to bring the floor to within 2–3% of the moisture content of any wooden subfloor.
- Wood flooring typically leaves our warehouse below 10% moisture content and may need to rise slightly to suit your building.
- Flooring from Canada and North America often arrives at 7–9% moisture content — suitable for drier climates but generally too low for the UK. A moisture content of 11–12% suits English conditions better.
- Modern well-insulated homes may need a different target from older Victorian properties.
- Complete all wet trades before delivery. Moisture transfers from wet walls, floors and ceilings into the timber.
- Keep the building enclosed — doors and windows shut, heating on. Maintain humidity at 35–55% and temperature at 15–25°C.
- Leave flooring in its cartons during acclimatisation. Remove polythene wrapping only if it blocks moisture movement.
- Spread boards around the building away from standing water and off the floor — especially above concrete.
- Do not place boards next to radiators or use gas or paraffin heaters nearby — both raise moisture levels in the air.
- Do not stack more than two or three cartons high. Use battens inside larger stacks to allow air circulation.
- Pre-finished flooring typically needs three to seven days to acclimatise; unfinished flooring takes longer.
- Take moisture readings throughout for accurate measurement.
Managing Moisture on New Build Sites
New construction sites almost always contain excessive moisture. Wood absorbs this and cups or expands — then contracts later in service.
- Install wood flooring as one of the last tasks on site. Other trades cause damage to finished floors.
- Use dehumidification equipment on wet sites to speed up drying.
- Under BS 882, one cubic metre of concrete (1:2:4 mix) contains approximately 187 litres of water. This must dry to around 3% moisture content before you lay any flooring. Allow roughly one day per 1mm of slab thickness — but always take a fresh moisture reading before you proceed.