General product information

How do I clean and maintain my new KUHN sliding door?

Wood is a natural product!

Deviations in structure and color as well as growth-related fluctuations are not a defect in a natural product like wood. Rather, this underlines the natural authenticity and individuality of your selected surfaces. With lacquered surfaces, slight deviations in the degree of gloss may occur due to different substrate materials. Slight color deviations are also possible. Slight shrinkage may occur due to changing temperature differences as well as changes in humidity, which may lead to warping of the sliding door panels.

General care instructions

Take care of our surfaces like pieces of furniture! Wood reacts to sunlight with discoloration. Adhesives and solvents attack the surface. Adhesive tapes should not be applied to the surfaces. Clean the surfaces with a lint-free cloth and solvent-free cleaning agents. If possible, never use abrasive, solvent-based or corrosive cleaning agents. Refrain from using the.

Use of furniture polishes

Polishing our high-quality surfaces is generally not necessary. Be sparing with water! Wood is a hygroscopic material, it reacts to moisture and wetness. Almost all of our products contain wood and/or wood-based materials; therefore, always clean only slightly damp and then wipe dry. In case of normal use, clean every 3 months with a hand-warm, damp window cloth or similar and wipe dry with a lint-free cloth. In case of increased soiling, clean with a lukewarm, damp cloth with a small addition of commercially available all-purpose cleaners, hand dishwashing detergents or neutral soap. Then wipe with a damp cloth and wipe dry with a lint-free cloth. Please do not use too sharp cleaning agents, scouring pads or scratchy cloths. These can destroy the surface.


Our high-quality sliding door elements must be stored dry and upright (plumb) in accordance with the valid climatic loads.


According to the IFT-Rosenheim, the Institute for Windows and Doors, doors are subject to stress group 0 (cabinet fronts. Walk-in closets, niche solutions, etc.) or stress group 1 (room-dividing doors, interior apartment doors for bathrooms/WC, etc.) depending on the installation situation. Doors in stress group 0 are not subject to any warpage tolerance limit. It is only necessary to ensure that they function properly despite warpage. Doors in stress group 1 may have a maximum warpage of 8 mm. The warpage is measured on the hollow side in the middle of the door leaf. If a complaint is made about warpage, it is recommended that you first wait for a heating period, as in the vast majority of cases the warpage will disappear after this time. In advance, it is necessary to check whether the delay is actually due to the door leaf or to a wall that is not perpendicular. It is also important to check whether the installation situation in the room corresponds to the climatic conditions. Please note that to avoid contact between the sliding door and the building structure (wall surface), a distance of at least 12 mm must be maintained. Otherwise, the door leaf may be damaged and malfunction if it is warped. If the min. wall distance is not maintained, the guarantee or warranty becomes void.


Avoid moisture and never spray the surface! Moisture flowing down can collect in the joint symmetry and cause e.g. glued-on glazing bars to detach. Only lightly dampen a lint-free and non-abrasive cloth and clean the surface with it.

Surface assessment

According to the IFT-Rosenheim, the Institute for Windows and Doors, there are the following instructions for the assessment of optical defects. The surfaces are to be inspected from a distance of 1 to 1.5 meters in diffuse daylight at a viewing angle appropriate to the use (grazing light is not permissible). If the defects cannot be seen from this distance, there is no justified reason for complaint.

Further optical or permissible requirements for surfaces

Locally, the frame timbers may stand out from the surface by up to 0.3mm. Minor bulging of the surfaces due to the fitting is permissible, provided the surface is not cracked and the strength is not impaired.

Glass assessment

The basis for assessing the visual quality of float and laminated glass is DIN EN 572-2 and DIN EN 572-5. In the case of toughened safety glass panes, this assessment is carried out in accordance with the "Guideline for assessing the visual quality of toughened glass" in accordance with DIN 1249 and DIN EN 12150-1.

A guideline for assessing glass quality has been drawn up by the Federal Flat Glass Association in cooperation with the Institute of the Glazier Trade in Hadamar. According to this, glasses are divided into certain zones in which glass defects are rated differently. Scratches and inclusions In the edge zone (5% of the clear width and height dimensions of the pane), inclusions and bubbles up to a diameter of 3 mm are permissible (1 piece per linear meter). Scratches are permitted in an individual length of 30 mm (sum of individual lengths max. 90 mm). In the remaining main zone, 2 inclusions and bubbles up to 2 mm in diameter are permissible. Scratches are allowed in an individual length of 15 mm (sum of individual lengths max. 45 mm). Optical defects In the case of so-called anisotropies, streaks and slight distortions are visible in the glass. Anisotropies are stress zones in the glass that are only visible under polarized sunlight. These are iridescence phenomena that can occur in toughened safety glass. These are unavoidable due to the production process and therefore do not represent a justified reason for complaint.

Spontaneous fracture for ESG

During glass production, both in the float process and in drawn glass, minute crystals of nickel and sulfur, so-called nickel sulfide inclusions, can form. Bubbles, eyes and small stones are extremely rare, but due to their size and the optical change (yard) they are usually clearly recognizable. The situation is different for the smallest nickel sulfide inclusions (NIS). Their size is usually in the range below 0.2 mm and they are therefore not optically detectable. When subjected to temperature stress, these NIS inclusions, provided they are located in the tensile stress zone of the toughened safety glass (ESG), can change their state form (allotropic transformation) and thus become considerably larger. This can lead to a very large increase in stress in the glass and, in extreme cases, to glass breakage without external influence. This glass breakage is called "spontaneous breakage", which, however, can only occur with toughened safety glass. Its occurrence is extremely rare and can still occur up to 10 years after manufacture.

A very good effect for protection against spontaneous breakage is achieved with the heat soak test (HST). However, absolute nickel sulfide-free float glass production is not yet possible. Heat soak test (HST) To prevent spontaneous breakage, toughened safety glass is subjected to a heat soak test in accordance with DIN 14179 after production. The panes are stored in the oven at an average temperature of 290°C (±10°C) and kept at this temperature. ESG panes with nickel sulfide inclusions and a resulting increased risk of breakage are destroyed and sorted out with 95% certainty by this test even before delivery. However, 100% certainty is not possible with this.

Glass breakage due to spontaneous breakage does not constitute a warranty claim.

Profile surfaces

In the case of whole profile lengths, minimal differences in length and clamping points on the profiles are possible due to the production process and do not constitute grounds for complaint. Slight differences in color shade due to material or process-related permissible scattering may occur and also do not constitute grounds for complaint.

General Product Information (PDF)

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