The substructure on which the wooden floor will be installed will usually depend on the specifics of the site, the type of wooden floor and the customer’s needs. The requirements of the instructions for laying wood flooring must be followed when installing the subfloor structure and laying the wood floor. Below we present the most commonly used wood floor constructions and discuss their pros and cons.
Simple, economical and reliable installation method where the wood floor is glued directly to a well levelled concrete subfloor. Wooden floors can often be glued to a concrete subfloor in new-build flats, detached houses and other applications where no additional levelling or lifting is required.
The construction has the following advantages:
- Cheaper and quicker than all other subfloor bonding constructions. In many cases, e.g. when laying factory-finished floors, only glue will be required for installation.
- Minimal lifting of the floor height. Laying a wooden floor will raise the level of the subfloor, but in this case it will only raise the thickness of the wooden floor, minimising the space in the room. Knowing the thickness of the future wooden floor in advance will make it easy to combine it with other floor coverings such as tiles.
- Simple design. It is a well-known truth: the more complex the construction, the greater the chance of making a mistake during one of the installation phases, which will result in a poor quality construction. Wooden flooring glued to a concrete subfloor is one of the simplest and most reliable constructions for laying wooden floors and does not require any special craftsmanship.
- Such floors are the easiest to preserve in the event of various emergencies. For example, in the event of flooding, solid wood floors can still be salvaged in a short time by vacuuming the water out (multi-layered wooden floors are usually not salvageable as they often delaminate when flooded). It is true that once the floor has dried out, it will have to be sanded, sealed and recoated with varnish or oil, but the wooden floor itself will not have to be removed. If the flooring is poured on top of other substructures, it is unlikely to be salvageable and the whole structure will have to be dismantled.
- The structure is ideal for underfloor heating.
Please note that:
- The concrete substrate to which the wood flooring is to be bonded must be completely smooth, strong, physically ‘sound’, clean and have a slight roughness. Requirements for the smoothness of the subfloor: a tolerance or undulation of 3 mm per 2 m section. Slight unevenness at the edges of the room or in doorways may be smoothed with special machines.
- Smoothing compounds can be used to level a concrete substrate that is not very smooth, but this may reduce the reliability of the structure. This is because levelling compounds are often not used in accordance with the manufacturers’ requirements, are too thin or too thick and can bounce off the concrete when the wooden floor is laid. Another common problem is the incompatibility of the levelling compound with the wood floor adhesive, which can cause the adhesive to adhere poorly, to react, or not to adhere at all to the substrate. In addition, levelling concrete floors with levelling compounds significantly increases the cost of the floor. For all these reasons, the use of OSB plywood or a suitable adhesive is often recommended for levelling a less than smooth concrete subfloor.
- The best option is to choose the right adhesive!