binderholz CLT BBS

BINDERHOLZ CLT BBS | SORTING OF THE COVER LAYER The change in the wood moisture and thus the effect on the optics of visual surfaces is divided into 3 steps: Production: The cross-gluing of the kiln dried lamellas (wood moisture 11%+/- 2%) reduces the natural shrinkage and swelling of CLT BBS to a minimum. Shell construction and assembly: CLT BBS is exposed to natural, seasonal climate changes during the assembly and shell construction period. Thus, wood moisture can change depending on the prevailing climatic conditions. Building use: During a period of up to 3 heating seasons, CLT BBS will level out at an average wood moisture content of approx. 8 - 10%. This adjustment of the wood moisture can lead to optical changes, such as cracks or joints in CLT BBS with visible surfaces. This does not affect the static properties of CLT BBS. Even the most careful production or low wood moisture fluctuations of CLT BBS cannot completely exclude the formation of cracks and joints. In visible quality, their appearance can be enhanced by opaque coatings. Exposed external positions of CLT BBS have a generally positive effect on the load-supporting behaviour, but on the other hand lead to a stronger shrinkage and swelling and thus to increased cracking and/or joint formation. Surface CLT BBS* Characteristics Residential visible AB Industrial visible BC Non-visible C Branches Healthy branches firmly grown together: allowed Black branches: occasionally allowed Allowed Allowed Compression wood Allowed Allowed Allowed Dowels & repaired resin pockets Allowed Allowed Allowed Appearance Balanced No requirements No requirements Resin pockets Only up to 3 mm x 50 mm allowed Allowed Allowed Insect infestation Not allowed Not allowed Occasionally allowed Pith Occasionally allowed Allowed Allowed Quality of surface treatment Occasional small flaws are allowed, e.g. small tears caused by wood plane Occasional small flaws are allowed, e.g. small tears caused by wood plane Faults allowed Ingrown bark Occasionally allowed Occasionally allowed Allowed Cracks Occasional surface cracks allowed Occasionally allowed Allowed Discoloration Slight discoloration allowed Allowed Allowed Bonding Occasional open joints up to max. 1 mm allowed Occasionally open joints up to max. 2 mm allowed Open joints up to max.4 mm allowed Wane Not allowed Not allowed Allowed * Based on DIN EN 13017-1:2000-01 and in compliance with the strength sorting EN 14081-1 (S10) © Rene Riller Fotografie