A well prepared sub-floor is one of the most important elements of floor construction and its quality will affect further use of the wood flooring. It has to be strong, level and dry. Several sub-floor choices are available: concrete; using levelling compounds; OSB or plywood sheets; using battened or sprung flooring.

The simplest, reliable and most cost effective method is to glue the floor planks to a concrete sub-floor. This method is also suitable for heated floors. A concrete sub-floor should be levelled, the humidity of concrete may not exceed 2.8% Moisture Content (MC).

If the concrete sub-floor is not level enough, levelling compounds can be used. Use them strictly in accordance with the instructions of the manufacturer.

A cheaper and simpler way to level an uneven concrete sub-floor is to use OSB or plywood sheets (suitable where the deviation or 'waviness' of the concrete sub-floor does not exceed 10mm). We note that this method of construction is not ideal for heated floors.

In order to improve the comfort of the floor, installing a sprung floor, therefore increasing comfort, may be used. Laying the floor using battens is suitable when faced with very uneven sub-floors, where there are significant floor height differences between premises.



Wood is very sensitive to changes in the environment. In summer, when it is hot and humid, when the relative humidity is over 65%, floor planks may deform leading to cupping or warping. In winter during the heating season, wood evaporates humidity if the humidity is lower than 45%, gaps may appear in the flooring. All these are natural processes, therefore to avoid deformation of the floor relative humidity should be kept at 40-60%.


Temperature of the premises should be +18-24°C.


  • All wet works (plastering, painting etc.) should be complete in the room where the floor will be laid, thus ensuring that the room has a stable humidity and temperature.
  • After delivery, the packed floor planks should be kept on a level and dry sub-floor in the room where they will be installed. Unpack the floor planks immediately before installation.
  • When installing oak flooring manufactured by UAB ECOWOOD, we recommend that it is glued to a sub-floor. It is not ideal to install the flooring in a 'floating' manner when they are not fixed to a sub-floor using adhesion ie. just connected to each other by gluing the tongues and grooves.
  • Use glue that does not contain water for gluing the floor planks to the sub-floor ie. Stauf SMP -940 that contains no isocyanates, water or solvents.
  • It is recommended to orient the floor boards into the light, as the joins of the planks are less visible.
  • Leave a gap of 1–1.5 cm from the walls.
  • When laying floors, cutting floor planks and baseboards, dust is unavoidable, therefore we recommend to cover the floor planks with colourless oil after installation.
  • We recommend hiring experienced specialists for laying the floors, since only well installed floors will serve you for many years.


Flooring manufactured by UAB ECOWOOD is suitable for heated floors in most cases. Please remember that the installation of the sub-floor for heated floors and the use of such floors can be complex.

The main rules are:

  • When installing the flooring, the humidity of the concrete sub-floor should not exceed 1.5% MC.
  • Heating elements in the sub-floor should be placed equally and at the same level. The
    temperature of the whole area of the floor should be even and not exceed +28°C.
  • The heating of the sub-floor should be switched on at least 4 weeks after laying the levelling layer.
  • After turning on the heating, the temperature of the sub-floor should be increased every day by +5°C until the maximum heating capacity is reached.
  • The heating period during drying of concrete should not be less than 24 days. Before laying the flooring, the sub-floor should be heated for at least 5 or more days.
  • For laying heated floors you should choose the glue very carefully. Suitability of glue
    for heated floors should be indicated in the instructions.
  • 2-3 days before installing the floor, the temperature of the sub-floor should be gradually reduced to +18°C - +21°C and it should be maintained during installation. The temperature of the room should be the same.
  • After installation of the floor, the temperature of the sub-floor should be maintained (from +18°C to +21°C) for at least 3 days. Then the desired temperature can be set gradually.
  • It is particularly important to maintain proper environment conditions for heated floors during use: relative humidity should be 40-65%; temperature +18°C - +21°C. Otherwise gaps may appear in the floor due to the natural qualities of the wood noted above.