Inspection

When inspecting the sub-floor, please pay special attention to the following points and then treat the sub-floor accordingly.

• A high degree of unevenness of the floor.
• Cracks in the floor.
• Inadequate pressure resistance of the floor.
• Too porous a surface.
• If the floor has expansion joints, check whether there is a need for special joint covers and check whether these covers are well-bonded to the floor covering.
• Heavy soiling of the floor by, for example, oil, wax, varnish, adhesive and paint residues, etc.
• Are there undesirable height differences at the threshold with other rooms?
• Does the temperature or humidity in the room to be installed fluctuate or remain within standard limits?
• If there is an underfloor heating system, ensure that instructions are available for switching on the heating and check that these regulations have been followed up until now. If the floor temperature is abnormal, this can have far-reaching consequences.
• Is the sub-floor non self-supporting or is it self-supporting but not ventilated or inadequately ventilated?
• Is the non self-supporting floor at the same level as or below the upper surface of the ground?
• Is the non self-supporting floor below the upper surface of the ground and in groundwater?

The sub-floor

The sub-floor must be permanently dry, free of flaws, clean, resistant to pressure and stress and flat. Check the hardness of the surface before starting work using a hard, sharp object. Scratch horizontal and vertical lines across a surface area of about 100cm2, about 1cm apart. If the surface layer within the drawn square of ca. 100cm2 does not fracture then you can assume that the hardness is sufficient.

Adhesive can only be applied to industrial floors after a special pretreatment (e.g. priming and levelling). Please seek advice on this matter from the supplier of your adhesives and levelling compounds.

Moisture content of the floor

All floors, with the exception of cast asphalt, have a designated maximum permissible moisture content (so-called intrinsic moisture content).

After installation, all sub-floors require a certain drying time before floor covering can be laid. The drying time depends on the thickness of the construction, weather conditions, whether heating is available or not, ventilation conditions, etc. If the moisture content of the underlying structural floor is not within the permissible average intrinsic moisture content, then the applied, apparently dry top floor is not suitable for bonding hard floor covering. Do pay attention to this point!

Always assess your particular situation carefully. Is there, for example, a moisture-proof foil between the structural floor and the top floor? Can it be demonstrated that the moisture content of the structural floor lies within acceptable limits?

In all cases, measure the moisture content of the floor before proceeding. If in doubt, always consult an expert.

A reliable device for determining the moisture content is a CM-unit. The measured values must be reported in writing to the customer.

Note: On floors having underfloor heating, do not use any method for measuring the moisture content of the floor that requires holes to be made (e.g. the CM-unit). Holes could damage the heating system. Where underfloor heating is installed, there are usually starting instructions or a so-called heating up protocol. By adhering to this, measurement of the moisture content becomes superfluous.

Pretreatment of the top floor

In principle, all sub floors must be PRIMED and LEVELLED. If not levelled, even the smallest unevenness of the sub-floor will be visible. If desired, consult the supplier of the adhesives and primers. Primers and levelling compounds must be applied following the instructions provided by the manufacturer. This ensures that there is permanent bonding with the sub-floor, no cracking and adequate pressure resistance. The minimum thickness of levelling compound for rolling loads is 1.5 to 2mm. When dispersion adhesives are used, dense non-absorbent sub-floors must have been levelled with a sufficiently thick (min. 2mm) layer of levelling compound. After flattening, cut off insulation foil along walls and joints, and also cut off protruding insulation material and protective foil.

Installation conditions

• Ambient temperature: minimum 18°C.
• Sub-floor temperature: minimum 15°C.
• Relative humidity: maximum 70%.
• Not only must the ambient temperature be at least 18°C, but also the temperature of the floor covering and also the primer and adhesive.
• When measuring the moisture content, determine whether the floor is of uniform thickness. Thicker layers require a longer drying time.
• Ensure there are optimum drying conditions.
• Apply the primer using a roller, not with a drawer.

Inspection of the sub-floor

Always check that the floor is permanently dry, free of flaws, clean, resistant to pressure and stress and flat.

Composition of the sub-floor & permissible moisture content for laying floor coverings. Values measured using the CM-unit

• Sand/cement < 2.5%
• Anhydrite 0.3% to 0.5%
• Magnesite < 0.3%
• Xylolite 8 - 12%
• Cold bitumen < 2%

Storage of the floor covering

Ensure the floor covering is always stored on a flat floor. If not, this can cause problems later.

Inspection of the floor covering

Before leaving the factory, the floor covering is carefully inspected to ensure high quality is guaranteed. Nevertheless, always visibly inspect the floor covering before it is fitted. Any shortcomings can only be rectified prior to fitting. After installation, only shortcomings that were not initially apparent can be dealt with. In order for complaints to be dealt with, specific data such as our invoice number and order number will be necessary.

Please contact the office for full details relating to the installation of individual products, as these vary dependent on your sub floor type and condition.

Our technical department will be happy to assist with ensuring that your installation specification is tailored to suit your individual requirements.

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