Technical properties

Technical properties of HOISKO CLT elements

Cross-laminated timber challenges concrete and steel, as it reaches the level of steel in terms of load-bearing capacity and is lighter in weight than concrete. HOISKO’s CLT has edge-glued seams, which improves the density of the product and makes the surface more visually appealing. Edge-gluing also makes HOISKO CLT a suitable material for visible surfaces. In addition, edge gluing allows construction without a separate vapour barrier. HOISKO CLT can also be manufactured without edge gluing. However, the technical properties related to airtightness and moisture required of structures cannot be guaranteed in HOISKO CLT without edge gluing.

Product information

  • Cross-laminated timber (CLT) is used in interior and exterior wall structures as well as in base and intermediate floor structures.
  • The standard thickness of our CLT products varies from 90 mm to 300 mm. We can produce slabs with a thickness of 60–400 mm.
  • The maximum length is 12 m, and the maximum height is 3.5 m.
  • The wood we use is domestic softwood. The strength class of the softwood is C24. The wood is sorted visually, which ensures a uniform surface. Normal, healthy/solid knots of the wood and low peeling are accepted on the surface of CLT.
  • The number of lamella layers may vary from 3 to 10.
  • In three-layer slabs, the overlapping layers are perpendicular to each other.
  • In five- and seven-layer products, the outer lamella layers may also be parallel.
  • The surface lamellas can be either vertical or horizontal.

You can download the product specification sheet by clicking on this link.

Our material bank contains all the technical details of the product which may be useful in the planning work.

Treatment and maintenance of CLT elements

We recommend that you treat HOISKO CLT surfaces as early as possible during the construction phase, preferably immediately after the roofing phase. Applying a protective treatment during construction prevents the wood surface from getting dirty, protects against moisture fluctuations, and levels the natural expansion and contraction of wood. Primers and surface treatment agents protect the wood by reducing the effects of moisture and sunlight.

Only common, well-proven treatment agents designed for wood surface treatment should be used to treat the finished CLT surface. However, the treatment agent should not be a “sealing” agent.

CLT is a natural material, so you should be prepared for the material to live. Small cracks and other normal signs of living may occur in the elements as a result of drying. However, these do not affect the structural quality of the wood.

The seasons should be taken into consideration when installing CLT. In winter construction, the building may need to be heated. Of course, heating or drying may also have to be carried out in construction site during other seasons, for example in connection with casting. Use air dryers with care and avoid exposing the elements to rapid changes in temperature or humidity.

When you build a home or public building with HOISKO CLT, you will receive a five-year warranty on the CLT products from the date of purchase.

When you order HOISKO CLT elements, you will receive a comprehensive user and installation manual, which provides more detailed information on the surface treatment, storage and installation of CLT.