It is usually said that wood is stronger if it has a higher density. A method often used to determine the strength of a wooden floor is the so-called Brinell method. A ball of hard metal is pressed into the wood surface with a defined force and then the impression on the surface is measured. This procedure tests the resistance to point loading.
Harder wood is used for surfaces that are exposed to greater loads, such as parquet for dance halls. Harder woods are oak, beech, maple, ash and various tropical species.
Strength plays a big role in this feature of wood as well. The denser the surface of the wood, the more resistant it is to wear. Since the wood has a final treatment, care should be taken that the coating with which it is treated has the appropriate wear resistance. The price of parquet increases, but this is a prerequisite for the durability of the wooden floor.
For floors in residential areas and in ballrooms, the property of sliding is allowed and desirable to a certain extent. For spaces such as hotels, hospitals, schools, classrooms, theaters, multimedia centers, offices, shops, restaurants, department stores – practically in all public buildings, floors must be safe for walking. At the EU level, there is regulation BGR 181 (3) for public purpose premises that are used for business. Requirements related to floors in sports halls are defined according to DIN V 18 032-2. These floors must be safe to walk on and must not be slippery. In order to achieve these features, there are various types of surface care and treatment products.
On one hand, we distinguish impact noise, which is transmitted through walls and floors into neighboring rooms, and on the other hand, noise that spreads through the air. Speech and various sound sources create sound that spreads in space and is reflected or absorbed by building elements, furniture and decorations. The properties of the surface are decisive when it comes to room acoustics: smooth and hard surfaces such as parquet reflect sound, soft and structured ones absorb it, so the optimum is achieved with a combination of wooden floors for the house and textiles.
Compared to the ceiling, the glued parquet transmits the sound equally into the next room. With floating floors, especially with built-in elements that have insulating properties, the protection against footfall noise can be improved.
The thermal conductivity coefficient λ for different types of wood ranges between 0.10 and 0.20 W/mK. The values taken into account according to DIN 4 108 for deciduous species are 0.20 and for coniferous species 0.13 W/mK. Although wood retains heat relatively well, so these types of floors are called warm, the thermal conductivity coefficient is still in the domain that the parquet can be installed on floor heating, i.e. when the thermal resistance is not higher than 0.15m2K/W. In principle, it is possible to install all types of parquet on floors with underfloor heating. For these purposes, a parquet with a smaller thickness is used. The prices of parquet with smaller thicknesses are lower.
Parquet is delivered and installed with a medium wood humidity that corresponds to a room climate of 20 to 22°C with a relative air humidity of approx. 50%. Relative humidity is usually higher in summer and lower in winter. Due to this, the humidity of wood also changes, which leads to a change in the shape of parquet: in the summer, the parquet swells, and in the winter, it decreases in volume, which can lead to the formation of joints. That is normal! The formation of joints can be limited if the rooms are adequately ventilated in winter. Veneered parquet skirting boards made of soft wood will not bend and peel off like those which are solid.
Water absorption property
The water absorption property of wood depends on the rate of moisture absorption through the wood. Wood with a higher rate of moisture absorption has more voids between its fibers, which in the wood’s natural form served to store water. This property causes the wood to dry faster, but it also gives it a greater ability to absorb. On one hand, this can save time on the surface coating of the parquet, since the time between work steps is shorter. On the other hand, rapid and uneven drying can occur (especially when applied with a spatula). For these reasons, it is recommended to use a roller for coating wood types with greater absorption (e.g. beech, ash, larch).
Different fire safety standards apply to wooden floors than to walls and ceilings. The flame spreads less on this type of floor. In general, according to DIN 4102-4, wood is classified as a normally combustible material, while according to DIN EN 13 226, oak strip parquet and parquet lamella mosaic are classified as a highly flammable material (B1). In analogy to this, it also applies to other types of oak parquet with a useful layer of at least 8 mm.
Parquet has a positive effect on all human senses. It is produced with low energy consumption and from renewable raw materials. Modern adhesives and surface treatments do not contain or have a very low percentage of solvents or formaldehyde. People prone to allergies prefer parquet surfaces that collect the least amount of dust, so that there are as few dust mites and allergens in the space as possible. Consider this aspect when you think that the price of a parquet or wooden floor is high.