CLT Panels
Technical Description
Product – CLT
Prefabricated construction elements made of Cross Laminated Timber (CLT) – environmentally friendly multilayer cross bonded timber structure providing exceptional technical characteristics and application possibilities.
Technical approvals
European Technical Approval ETA – 15/0906 and CE certificate No. 1359-CPR-0708
Lay – up and production
CLT production is carried out in 4 main steps
- Finger – jointing – crucial part of the raw material quality management process allowing to achieve the required timber strength class according to EN 14080 (class C24) and board lengths up to 13.80 m. Finger – jointing is applied to all raw material used in CLT production carried out by Cross timber systems
- Planning. Process carried out to ensure precise dimensions of the finger-jointed boards used both on internal and external layers of CLT. Planning is particularly important process to ensure good quality surface adhesion between the CLT layers.
- Cross laminating. Particular process “holds” the idea of CLT. Process provides possibility to produce trough-out loadbearing structures with dimensions up to 13.8 x 3,1 m and exceptional dimensional stability used for building and construction purposes
- CNC machining. Precision pre-cutting according to technical drawings (generated from architectural drawings) provides possibility of producing ready – to – assembly prefabricated elements
CLT is widely used in combination with other construction and insulation materials allowing easily to achieve necessary energy efficiency, design and architectural requirements
Dimensions and specifications
| Item | Dimension/ Specification | |
| Cross laminated timber | ||
| Length | m | ≤ 14 |
| Width | m | ≤ 3.15 |
| Thickness | mm | 60 to 260 |
| Number of layers | – | 3 to 7 |
| Maximum width of joint between boards within one layer | mm | 3 |
Timber Species and Strength classes
Timber species – European spruce (picea abies) or equivalent softwood, e.g. scots pine (pinus sylvestris), kiln – dried, quality graded and finger – jointed acc. to EN 14080 and EN 388. Strength class – Cover layer: C24 according to EN 338; Cover layer and inner layer: ≥ 90 % C24 / ≤ 10% C16. Intended use: Service classes 1 and 2 according to EN 1995-1-1
Laminating
Structural adhesive with suitable behavior in fire and suitable long term behavior is used according to standards EN 301 or EN 15425 – formaldehyde – free 1K PUR adhesive used throughout the CLT production process. PUR adhesive due to its technical, curing and environmental aspects is currently the most popular and widely used adhesive in structural timber industry
Weight
The mean density of CLT produced from Nordic spruce is ≥ 480 kg/m3
Moisture content
Moisture content: 12% +/- 2% within one member of cross laminated timber the moisture content shall not differ by more than 45 according to EN 12183-2
Dimensional stability
Panel size – 0.02 % change for every 1 % change in panel moisture content;
Panel thickness – 0.24 % change for every 1 % change in panel moisture content;
Thermal conductivity
ʎ=0.13 W/mK in accordance with EN 12524
Heat capacity
An important factor helping to create thermally more stable living environment and Characterizes the material’s ability to obtain and then distribute a certain amount of heat. Cross Tiber Systems CLT is made of timber, that has a high thermal conduction c=1600 J/kgK in accordance with EN 12524
Water vapor resistance factor
µ=20 to 50 in accordance with EN 12524
Airtightness
The airtightness off Cross Timber Systems CLT has been tested according to EN 12114. No extra air tightness barrier needed if appropriate gap sealing technology applied
Sound insulation
CLT sound insulation and vibration absorption is entirely dependent on the thickness of the CLT panel, wall or slab pie buildup and additional special absorption materials (f.i. sound insulation tapes) used. Sound insulation is calculated by engineers based on common practice. Standard pies and insulation rates have been provided further in the document.
Reaction to fire
D-s2, d0 in accordance with Commission Decision 2003/43/EC
Fire resistance
Charing rate of 0.65 mm/min in accordance with EN 1995-1-2
Use of cross laminated timber in the structure
Cross laminated timber has been approved for utilization classes 1 and 2