Surface quality

Surface quality:
Optical requirements as needed

X-LAM is a natural product whose appearance varies. Wall and ceiling elements made of X-LAM can be produced in different surface qualities depending on the requirements. We distinguish between non-visual quality (NSI) and visual quality (ISI). The choice of surface quality depends on the later use of the panel and should already be taken into account during planning.
The choice of surface quality depends on the later use of the panel and should already be taken into account during planning. Our samples and the definition in our product brochure give a first impression of the surface quality. Should you wish to gain a more meaningful impression of the surface qualities, it is always advisable to visit reference buildings or currently produced panels in our factory.

Visual quality (ISI)

The visible quality is recommended when the builder wants to see the wood structure and show the naturalness of the product. This surface quality is most often chosen for the visible areas in office, industrial, residential and commercial buildings. Specially sorted and finger-jointed lamellas are used for the visible outer layer. In visual quality, healthy, firmly grown knots and wing knots as well as occasional black knots are permissible. Outstanding knots ≥ 30 mm are repaired with knothole plugs, “shuttles” etc.. Fungal and insect infestation are excluded, discolouration due to blue stain is largely absent, resin pockets and visible pith are permissible. Based on the production wood moisture content of 10 ± 2%, the maximum joint width between two lamellas is limited to 4 mm as delivered. Occasional glue penetrations may occur between the lamellas. The visible surface is sanded again after production. As a result, planing marks may still be partially visible. The exact requirements can be found in the “Cross laminated timber data sheet” of the Studiengemeinschaft Holzleimbau under the item “Industry visual quality”.

Non-visual quality (NSI)

The building material is not visible, as the load-bearing walls and ceilings are subsequently clad on site. In accordance with the specifications of the European approval, the selection of the initial lamellae is made purely from a static point of view from strength class C24 and with a small proportion from strength class C16. Thus, joints of up to 6 mm are also permitted between the slats in the transverse layers and up to 3 mm in the longitudinal layers. In addition, discolourations such as blue stain and red and brown nail-resistant stripes are permissible. Failing branches, even in larger numbers, are not patched up if they are not of visual quality. Due to the gluing technology, glue can also partially escape from the surface of the boards.

Special surfaces

For special optical requirements, various special surfaces can be produced. For example, different types of wood can be used as the visible outer layer (e.g. silver fir or larch), but it is also possible to glue on a rod-glued solid wood panel. The application of other additional layers such as bamboo veneer or kiri is also possible and expands the surface design possibilities enormously.

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