Solid Wood Flooring Fitting Guidelines
The conditions in which the flooring is stored and laid, must be the same as when the room is in normal use. This is very important as a change in the environment may cause the flooring to distort once fitted. The heating must be in operation and any wet trades involving plaster, cement and decorating completed and fully dry. Prior to fitting, all solid wood flooring requires at least 3 weeks to acclimatise in what will be its normal environmental conditions. The building should be heated (including normal ventilation) prior to the floor being fitted. There should be no visible or measured signs of moisture or condensation. The temperature should be around 15-20°c and the relative humidity should be between 35% – 65%.
Whether the sub-floor consists of floorboards, chipboard or plywood it is essential to check the floor has adequate protection from moisture below. The base must be level to no more than a 3mm variance along a 3m straight edge. Uneven floors can be levelled by sanding or screwing down chipboard.
These must be dry and flat. It is wise to apply a damp proof membrane on all screeded sub floors prior to fitting wood flooring. As with other sub floors the screed must be level to no more than 3mm variation over a 3m length. If there is too much variation we recommend using a self-levelling compound. New concrete normally takes around 1 month per 25mm to dry or 1 day per mm.
It is necessary to leave expansion gaps around all fixed points and the floor’s perimeter, so that the flooring has room to expand. This space between the wall and flooring will be covered by the skirting board. Note: During the winter period, flooring that is acclimatised and laid whilst the central heating is on full, will tend to expand during the summer, and so will need larger gaps than a floor that is laid during the summer months.
The gaps at the end of the boards should be filled with a rubber or cork strip, which snugly fills the gap. The minimum gap left at each end should be no less than 10mm. The size of the gap can be determined by leaving a 1mm gap for every meter of flooring laid. Solid wood flooring expands far more across its width than its length, therefore this gap is left empty. The minimum gap left at each side should be no less than 15mm.
20mm flooring gap ratio:
A 2mm gap must be given for every 1 meter of floor width on both sides.
14mm flooring gap ratio:
A 3mm of gap must be given for every 1 meter of floor width on both sides.
> Flooring should never be left outside in the elements, it is hygroscopic and will absorb moisture and therefore shrink when fitted.
> Before fitting it is important to identify where any services, especially electrical, water and heating systems are located. If a nail goes through a water pipe during fitting it will leak, be absorbed by the floor and expand causing rafting.
> The conditions in which the flooring is stored and laid, must be the same as when the room is in normal use.
> It is essential to check the floor has adequate protection from moisture below.
> The sub-floor or screed must be level to no more than 3mm variation over a 3m length.