Luke Floorwalker

Cornwalls wood floor specialist



OWNER RESPONSIBILITIEShow much Hardwood flooring do I need and what do I need to do before the wood arrives?

Engineered hardwood floors are a natural product and as such are subject to many variances in both colour and character, this is to be expected at all times.

A 5% cutting or waste allowance must therefore be added to the net square meters required for the site to be installed. Most quality engineered boards are produced with a manufacturing tolerance of +/- 1.5% on the dimensions of the board, so a 189mm face width board could be out of true by a max of 2.83mm – which would cause gaps – an allowance must be made to discard these sections when fitting. So, as a guide 7 – 15% wastage should be allowed for, dependent upon: – the quality of the product, the intricacies of the site to be fitted and any additional detailing required.

The owner assumes all responsibility for final inspection of the product quality prior to installation.

Luke Floorwalker will determine that the job site environment and the sub-surfaces involved meet or exceed all requirements within the supplied manufacturer’s instructions. These moisture records will be retained by Luke Floorwalker and a copy issued to the client upon of the installation, for warranty purposes.

  • All flooring must be stored in the correct conditions prior to installation.
  • Timber ‘must not’ be stored on site until all sub-floors, Plastering, cement work, decorating and all other wet work is completely dry.
  • The client has final responsibility to ensure that they have received the correct species and finish as per their order.
  • Luke Floorwalker will inspect each board and de-select pieces with defects.
  • Engineered Hardwood floors are suitable for installation in Properties below ground, fitting in Conservatories and in Bathroom areas providing that the strict guidelines outlined herein are adhered to.
  • It is normal to use stain, Putty or filler stick for defect correction or minor dimension differences.

Whilst Luke Floorwalker will take steps to ensure that the  floor maintains an evenness of colour, however, hardwood floors are a natural product and as such are subject to many variances in both colour and character, this is to be expected at all times.



The aim of acclimatising wood flooring is to allow the moisture content of the timber to adjust to the normal expected day to day conditions of the building once it is occupied.

Prior to installation, Luke Floorwalker takes the responsibility to ensure that the internal site conditions are stable and are suitable for the installation of wooden flooring and fit within the tolerances set out by the relevant manufacturer. It is the responsibility of the client to inform Luke Floorwalker, who the manufacturer is and the product to be used.

A room temperature of between 18 – 22oC and relative humidity of between 45 – 65% must be maintained. In winter, especially when the temperature is 0oC or below and the air is dry outside, Luke Floorwalker recommends the use of a humidifier to stabilise site conditions if the site  readings are showing less than 45% humidity.

Screed/concrete subfloors must be under 4% moisture content using a Luke Floorwalker’s Tramex or other non-destructive moisture meter (2.5% CM Test/Din standard).

Failure to take these precautions could cause ongoing behavioural problems with the floor and will invalidate the manufacturer’s and the installation warranties. Should a client specify that fitting must proceed outside of these tolerances, Luke Floorwalker will insist that a disclaimer be signed.

The building should be fully enclosed including doors and windows. Heating should be operational have been run for 3 days , but reduced to minimum 48 hours before fitting the floor.

All ‘wet work’ must have been completed otherwise the moisture will transfer from walls, floors and ceilings into the hardwood flooring. The delivered flooring must be left in the packaging with polythene wrapping intact. The flooring must be stacked horizontally no more than 2 – 3 packs high or wide and should have ‘battens’ inserted between packs to increase air circulation.

Do not stack the timber next to functioning radiators.

Do not use gas or paraffin to warm the site once wood has been delivered.

The wooden flooring must be left in situ for 3-7 days before installation. However, it is only after further moisture checks have been completed by Luke Floorwalker, to confirm the wood flooring is in equilibrium with the site to be installed, that installation may proceed, meaning that this process may take longer.

Wooden flooring is usually delivered with a relative moisture content of between 8 -10%. The correct moisture content for installation within the UK is 10 – 12%, and in Cornwall …lets just say that we are surrounded by water, nowhere being further than 17 miles from the coast, and our humidity levels are greater here than any other county in the UK, we are at the extreme end of the Relative humidity levels,  this is why acclimatisation needs to occur. Testing must occur to ensure that the product is within these tolerances prior to installation. If the product has moved beyond 12% Rm then action must be taken to reduce the moisture /humidity readings within the site / product.

If your installer does not have the means to test effectively – consider carefully before engaging them further…this is your investment, and its warranty at risk.


A new installation site needs to dry out before timber flooring is delivered. There is nearly always excessive moisture on either new construction sites or major refurbishment contracts. In these instances the wood will absorb the excess moisture; resulting in stress issues such as ‘cupping’, ‘expanding’ and later ‘contraction’. Always protect against excessive moisture ingression, where it helps use ‘dehumidification’ equipment to stabilise the site conditions.

This is the reason why wood flooring installors should be one of the last contractors on site. Other trades can damage an excellent installation if care is not taken to safeguard moisture ingression in hard wood floors. In new building projects moisture is introduced into the fabric of the building throughout the construction process.

For example: Under BS882 a concrete mix of (1:2:4) one cubic meter of concrete will contain 187 litres of water. This will have to dry out to below 4% moisture content before the wooden flooring is installed. This may take up to 1 day per 1mm thickness of concrete to dry out. Therefore new moisture readings of the concrete subfloor must be taken prior to fitting of the hardwood flooring.


Not all hardwood flooring is suitable for installation over underfloor heating systems, nor all underfloor heating systems are suitable for hardwood flooring.

Engineered flooring should be used and a waterborne system should be used. However some manufacturers of electric matting will extend their warranty to cover the flooring material and some flooring manufacturers offer products that will cope with electric matting. Whilst Luke Floorwalker can offer advice, it is the owners responsibility to check of the compatibility of the two products (flooring and heating system).

  • The heating must have been commissioned at least 2 weeks prior to laying the wooden floor to achieve an ambient living environment,
  • The system must have been inspected before commissioning by a plumber and checked again by the same plumber 2 weeks later confirming that no pressure change has occurred in that period.
  • The heating should have been gradually increased in temperature over the 2 weeks culminating in a period at a max of 27oC of 48 hours, prior to delivery of flooring material. Once timber is on site the underfloor heating system should be run at ‘normal’ temperatures until moisture checks have been completed. Once these checks have been completed and the installation date is set, the heating should be reduced to ‘minimum’ for the period of fitting.
  • Luke Floorwalker strongly recommend the use of flooring temperature sensors (under the timber floor – fitted into the heating system) to ensure that the underside of the hardwood flooring is not subjected to temperatures higher than these parameters.
  • The concrete subfloor must be dry (not more than 4%moisture) to the full depth of screed with the heating turned off and the floor cooled.
  • The subfloor must comply with the specifications/conditions of the underfloor heating manufacturer.
  • 2-3 days after the installation of the engineered Hardwood flooring is complete the underfloor heating should slowly brought up to operating temperature  increasing 2 – 3oC every 24 hours – not exceeding 27oC within the subfloor.
  • Once the heating system is fully operational a minimum temperature of 18oC should be maintained thereafter.


When fitting to a sub base other than battens (eg. Screed, Plywood, chipboard), the sub base must conform to BS 8204 part 1 1987 which states: …that it must not deviate by more than +/- under a 3mm straight edge in any one direction…

Wooden sub structures must be sound and securely fixed. They must be a minimum of 18mm in depth in order to be supportive; this applies to Plywood and to chipboard.

Ply is always preferable to chipboard as flooring can be nailed to it but chipboard allows nails to work free an chipboard becomes less resilient if moisture is introduced (leaks etc).

If the sub structure is chipboard then a glue-down method or underlay and floating floor method should be chosen.

If there are moisture issues present within the subfloor Luke Floorwalker will be responsible for ensuring that the correct Epoxy Damp proof Membrane or vapour barrier be supplied and applied to prevent moisture ingress to the wooden flooring. This is a cost that is detailed within the quotation,

Where a floor is to be glued to a friable/powdery screed Luke Floorwalker will apply a stabilising solution to it to allow good adhesion. This is a cost that is detailed within the quotation .

In all cases Luke Floorwalker is to ensure that all screeds, Epoxy Damp proof membranes, and Adhesives are compatible with one another and do not invalidate one another’s warranties nor those of the Hardwood flooring manufacturer.