For prefab timber frame elements, we provide and use certified strength-graded wood that corresponds to the requirements of the Nordic Standard INSTA142.
Similarly to other wooden materials manufactured by Timbeco Woodhouse, the strength-graded wood is also calibrated (planed to the necessary dimensions), visually strength-graded and properly marked (stamped).
Wood is graded according to visual criteria, the most important of which are the number of branches, their dimensions and location (the so-called branch ratio). Strength-graded wood is given a construction wood strength class and each squared timber is marked separately. Strength-sorting may be carried out only by a person who has undergone special training and who has a valid certificate.
We manufacture strength-graded wood in the following strength and quality classes (according to INSTA 142): T3(=C30), T2(=C24),T1(=C18) and T0(=C14).