TECHNICAL GUIDE
XLAM Cross Laminated Timber is a state of the art, flexible system developed for use in the timber construction industry. It is a solid, static load bearing and space creating timber panel that is ideal for any structural requirement thanks to its flexible dimensions and outstanding physical properties. Durable bonding of the cross-wise layered construction made of high quality raw material guarantees that the components are absolutely dimensionally stable and rigid. Panels are made up of 3,5 or 7 and range in thickness between 45mm – 230mm.
Technical Guide
Cross-laminated timber (CLT or XLAM) is a wood panel typically consisting of three, five, or seven layers of dimension timber oriented at right angles to one another and then glued to form structural panels with exceptional strength, dimensional stability, and rigidity. Lightweight yet very strong, with superior fire, seismic, and thermal performance, CLT is also fast and easy to install, generating almost no waste onsite.
CLT offers design flexibility and low environmental impact. For these reasons, cross laminated timber is proving to be a highly advantageous alternative to conventional materials like concrete, masonry, or steel, especially in multi-family and commercial construction.
Span Tables
Cross-Laminated Timber (CLT or X-LAM) is a wood panel typically consisting of three, five, or seven layers of dimensional timber oriented at right angles to one another and then glued to form structural panels with exceptional strength, dimensional stability, and rigidity. It is lightweight yet very strong and has superior acoustic, fire, seismic, and thermal properties.
CLT is also fast and easy to install, generating almost no waste onsite. It offers design flexibility and low environmental impacts. For these reasons, cross-laminated timber is proving to be a highly advantageous alternative to conventional materials like concrete, masonry, or steel, and is especially well suited to multi-storey construction.
Surface Quality
Wood as a natural material is highly varied in its structure and has many natural characteristics. Often such characteristics can impair its visual appearance. Common visual characteristics are knots, annual rings and fissures. The surface appearance of XLAM South Africa cross-laminated timber panels is dependent on the surface type specified:
Visual Quality (VQ)
The surface lamellae are planed and sanded. At a moisture content of 15% +/- 2% a maximum gap width of 2mm between the lamellae is permitted. The edges of all VQ panels are chamfered as standard.
Industrial Visual Quality (IVQ)
The surface lamellae are planed and lightly sanded. At a moisture content of 15% +/- 2% a maximum gap width of 4mm between the lamellae is permitted.
Non-Visual Quality (NVQ)
NVQ panels will not be provided for visual surfaces unless specifically requested by the client. Unprepared NVQ surfaces are not suitable for the application of painted visual grade finishes.
Fire Safety
CLT is engineered to meet strict fire-performance standards.CLT can be designed to accommodate substantial fire resistance and unlike steel remains structurally stable when subjected to high temperatures. CLT panels can be produced with fire resistances of 30, 60 and 90 minutes. Mass timber is proven to be a safe option for use in any occupancy class. XLAM South Africa has undertaken fire tests which confirm the result of the many CLT burn tests that have been done worldwide.
- The outer layer of CLT chars in a controlled manner during fire exposure.
- The char layer insulates and protects the internal structural core.
- CLT maintains structural integrity under heat more predictably than steel.
30 minutes | 60 minutes | 90 minutes | 120 minutes
Download our certificates below:
Specifications
XLAM South Africa manufactures Cross laminated timber is according to the SANS8892 specifications using FSC certified sustainable timber.
Product
Cross Laminated Timber is a large-format, solid timber panel (with multi-layered, crosswise cross-section lay-up.)
Production
Finger-jointed and planed lamellas are loosely laid next to each other and the flat surfaces of the layers glued at right angles to one another. To avoid uncontrolled stress cracks, the narrow sides are not glued, but we are able to glue for visual quality panels. The layers are pushed laterally to dimension before applying the pressure in order to obtain a gap-free surface.
Dimensions
Lengths to 8.25 m Widths to 2 . 85 m
Thicknesses 45 to 230 mm
Standard widths 1 .20 m /1 .20 m /2 .10 m /2 .40 m/2.70 m
Approvals
Production is done in accordance with the draft SANS 8892 – Standard for performance rated Cross Laminated Timber.
XLAM South Africa is also FSC® chain of custody certified, which is an assurance that products are a sustainable resource.
Types of wood
Monterey Pine (Pinus Radiata)
Blue Gum / Flooded Gum (Eucalyptis Saligna Grandis)
Adhesive
Adhesives to SANS 10183-2. Approved for the gluing of load–bearing timber components.
Weight
Approx. 480 kg/m3 for determination of the transport weight
5 kN/m3 according to EN 1991-1-1:2002 for static calculations
Moisture content
15% (± 2%)
Dimensional stability
II to panel plane 0.01% per% change in moisture content
= to panel plane 0.20% per% change in moisture content
Air tightness
Airtight from a panel thickness of 90 mm.
Fire resistance
30, 60, 90 and 120 minutes achievable depending on panel build up and treatment.
According to the Classification Report of HFA, the average charring rate across several layers is for walls : 0.64 mm/min for ceilings : 0.71 mm/ min.
Insulation
-100mm CLT Panel:
U- Value: 1.11W(m2K) (Timber panel only – excluding build up)
-165mm CLT Panel:
U- Value: 0.70W(m2K) (Timber panel only – excluding build up)
Treatment
Available as untreated, surface treated or pressure impregnated.
Specialised treatments are available which aid in the preservation of the timber.
These treatments improve the durability of the timber and help prevent insect and fungal attack.
Advice on the specific treatments, and requirements, can be discussed during the design and specification process.
Further information on timber treatments, and the legal requirements, can be found on the website of the South African Wood Preservers Association (www.sawpa.co.za)