Kährs floors are suitable for both residential and public areas. Here we show an overview of some of the key criteria to consider when choosing a floor.


Questions to answer and consider when choosing a floor

• What will the area be used for
• How much traffic will the floor experience?
• Which species of wood has a sufficient hardness level?
• What is the expected lifespan of the floor?
• What type of surface treatment – lacquer or oil?
• How will the floor be maintained?

General recommendations for different areas

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Activity
Floor
9-10 mm 9-10 mm 15 mm 20 mm 15 mm 15 mm 15 mm 15 mm 12-13 mm 12-13 mm 10 mm 10 mm 7 mm 7 mm 15 mm 30 mm
Oil Lacquer Oil Oil Oil High gloss lacquer Oil Lacquer Oil Lacquer Oil Lacquer Oil Lacquer Lacquer Lacquer
RESIDENTIAL
Kitchen                                
Hallway                                
Living room                                
Bedroom                                
OFFICE
Reception                                
Corridors                                
Office                                
Conference room                                
HOSPITALITY
Reception                                
Corridors                                
Restaurant                                
Bar                                
Hotel room                                
RETAIL
Entrance                                
Cashier area                                
Showroom                                
Back office                                
SPORTS FACILITY
Basketball                                
Fencing hall                                
Aerobic studio                                
Gym                                
Squash hall                                

 

    Recommended
    If the wear and tear is equivalent to domestic use, installation is OK if a well defined maintenance program is followed.
    NOTE! If the wear is heavy in the area we do not recommend installation.
    Not applicable

Wear and tear

Ensure the specific floor has the ability to withstand wear and tear in its specified application area. Some areas experience higher floor traffic than normal. In such cases attention must be paid to the product quality and surface treatment. The anticipated floor traffic must always govern what product should be specified in an area. We recommend using oiled surfaces in areas with more extreme wear and tear, and always in conjunction with the recommended maintenance programme. Oiled surfaces are easier to maintain in such areas and will retain their quality and appearance if serviced on a regular basis. In other areas the choice of surface treatment is more flexible and both oiled and lacquered surfaces can be used.

Underfloor Heating

All Kährs floors, except Beech and Hard Maple, are suitable for use with underfloor heating. The electrical underfloor heating system must deliver no more than 80 W/m2, evenly distributed.

In a normally insulated house, with a properly functioning underfloor heating system, the temperature of the floor surface is generally 2°C higher than the room temperature. In a hot-water underfloor heating system, the flow temperature is usually 7–12°C higher than the floors’ surface temperature and must, therefore, never exceed 39°C.

For any system, the surface temperature of the floor must never exceed 27°C. This applies even next to and above radiator pipes, above pipe runs and under carpets, furniture etc.

Always follow the instructions and recommendations given by the supplier of the heating system.

Maintenance

Kährs floors are factory lacquered or oiled. For products with oiled surfaces we recommend the application of a fresh layer of oil instantly after installation, to enhance the durability of the floor. This is normally performed after the cleaning of the surface, before the handover of a project. This preventive maintenance should be done prior to installing furniture. For products with a lacquered surface, the need for additional coating is normally limited to areas with extreme use or areas with very heavy foot traffic.

Installation Methods

Kährs floors can be installed floating or glued-down (also nailed-down if the floor has a tongue & groove joint).

Floating installation
This method is the most cost-effective way of installing the floor. Sub-floor requirements are less demanding. However, the sub-floor must be dry, clean, flat and solid. We recommend that a 0,2 mm PE-film with 200 mm overlap is placed on the sub-floor as moisture protection. An intermediate layer can also be installed on any film to reduce footstep noise. The intermediate layer, e.g. Kährs foam or lump paper, should be installed edge to edge. When installing a Kährs wood floor on an organic subfloor you must make sure that the floor covering including subfloor construction never contains more than one layer of moisture barrier. An alternative is to use Kährs Tuplex, which combines both moisture protection and sound installation. In this case no other intermediate layer should be used.

The humidity of the room must not exceed 60% RH and both boards and the room shall be heated to at least 18° C.

Glue-Down Installation
The preparation and quality of the subfloor, in combination with the correct type of glue, are crucial for a well functioning surface. The demands and recommendations given here must always be followed in conjunction with instructions from the supplier of glue and preparation materials.

The following steps must always be taken for successful installation:

Acclimatisation
The wood flooring must be acclimatised prior to installation. If the wood boards have not achieved equilibrium in moisture content with their environment then excess expansion/contraction might occur.

Working conditions
The relative air humidity in the room must be between 30% and 65%. Too high air humidity leads to water absorption and causes expansion. All works which add significant quantities of water to the environment around the floor e. g. painting and wallpapering must be finished prior to wood floor installation.

See also Subfloor requirements for appropriate preparation prior to installation.

Subfloor Requirements

A floor can only be as good as the subfloor allows. Here are a few things to bear in mind regarding the substrate.

Substrate temperature
During application and until the glue is fully cured, the substrate temperature must be 15°C, or +20°C when applied in combination with underfloor heating.

Substrate quality
The substrate must be clean and dry, homogenous and even. It must also be free from oil, grease, dust and loose or friable particles. Paint, cement laitance and any other contaminants must be removed.

Subfloor evenness: (2m length +/- 3 mm)

Substrate preparation
Concrete and cementitious screeds must be mechanically prepared as necessary to achieve the desired substrate quality, then thoroughly vacuumed. On strongly absorbent cementitious substrates, use a primer or dust binder.

Substrate moisture content
Permissible substrate moisture content without underfloor heating is 2.5% CM for cementitious substrates (approximately 4% Gravimetric percent by weight.) Permissible substrate moisture content with underfloor heating is 1.8% CM for cementitious screed (approximately 3% Gravimetric percent by weight.)

Concrete/cement screeds
Must be ground and thoroughly cleaned with an industrial vacuum cleaner.

Anhydrite screeds/Anhydrite floating screeds
Must be ground and thoroughly cleaned with an industrial vacuum cleaner shortly before bonding starts.

Wood/gypsum boards (e.g. chipboard, plywood)
Glue/screw the boards to the substructure. They must be fixed to the substrate.