What is Cross-Laminated Timber (CLT)?
Cross-Laminated Timber (CLT) is a mass timber building system made from layers of structural timber boards glued together at right angles. This cross-lamination creates a strong, stable, load-bearing panel used for floors, walls and roofs.
CLT is increasingly used worldwide as a sustainable alternative to concrete and steel in residential, commercial and public buildings.
Is CLT suitable for African conditions?
Yes. CLT performs well in African climates when designed correctly. Projects across Southern and East Africa have demonstrated its suitability in varying temperature ranges, coastal environments and inland conditions.
As with any building system, moisture management, detailing and correct installation are critical — all of which are addressed during the design and engineering phase.
Where is XLAM active?
XLAM works across:
- South Africa
- Southern Africa
- East Africa (including Kenya and Malawi)
- Select international markets on a project-by-project basis
We manufacture locally and support projects regionally.
Is CLT more expensive than concrete?
CLT may have a higher upfront material cost, but when viewed holistically, projects often achieve:
- Reduced construction time
- Lower labour costs
- Smaller foundations due to lighter weight
- Earlier building occupation
- Improved sustainability ratings
When total project costs and timelines are considered, CLT can be cost-competitive or more economical than traditional systems.
Is CLT environmentally sustainable?
Yes. CLT is one of the most sustainable structural materials available.
- Timber is renewable
- Trees absorb and store carbon
- CLT locks carbon into the building structure
- Local sourcing reduces transport emissions
- Off-site manufacturing reduces waste and site disturbance
With correct sourcing and design, CLT buildings can achieve carbon-neutral or carbon-negative outcomes.
Is CLT fire safe?
Yes. CLT can be designed to meet fire resistance ratings of 30, 60, 90 and up to 120 minutes.
During a fire, the outer layers char, forming a protective barrier that slows combustion and protects the structural core. Unlike steel, CLT maintains structural integrity at high temperatures when properly designed.
Fire performance is always verified through engineering and compliance with local building regulations.
Is CLT approved under South African building regulations?
CLT is a SANS certified building material, meaning it is recognized as a standard building material, with no additional requirements for Agreemente certifications. It can be approved through:
- Rational design
- Performance-based engineering
- Fire engineering assessments
- Compliance documentation
XLAM works closely with professional teams to support regulatory approval.
What design freedom does CLT offer?
CLT offers a high level of design flexibility, including:
- Large open spans
- Exposed timber interiors
- Clean, modern aesthetics
- Precision-cut openings for windows and services
- Reduced structural depth compared to concrete slabs
CLT can be used alone or in hybrid systems with steel or concrete.
Can CLT be left exposed?
Yes. Exposed CLT is commonly used for its natural aesthetic, warmth and acoustic benefits. Fire ratings and surface treatments are considered during design to ensure compliance.
What is the maximum building height for CLT?
Internationally CLT has been used for high rise buildings up to 25 stories, with taller buildings currently in the works. CLT is very well suited for mid-rise buildings in the 4-12 story range where the benefits for speed and accuracy can be maximized.
Height depends on:
- Structural system
- Local regulations
- Fire strategy
- Engineering design
Hybrid systems can be used for taller structures.
How does CLT impact design timelines?
CLT can shorten design and construction timelines when integrated early. Early coordination allows:
- Faster structural resolution
- Accurate BIM modelling
- Reduced on-site changes
- Improved cost certainty
Early involvement is key to unlocking these benefits.
Does XLAM support BIM workflows?
Yes. XLAM works with BIM-based design and coordination, enabling:
- Accurate prefabrication
- Clash detection
- Streamlined collaboration
- Precise manufacturing output
What documentation does XLAM provide?
Depending on scope, XLAM can provide:
- Technical data sheets
- Panel layouts
- Manufacturing drawings
- Structural coordination input
- Sustainability information
How is CLT constructed on site?
CLT panels are:
- Manufactured off-site
- Delivered with pre-cut openings
- Installed using cranes
- Mechanically fixed in place
This results in:
- Faster installation
- Cleaner sites
- Reduced wet trades
- Lower labour requirements
How much faster is CLT construction?
Case studies show that CLT can reduce construction time by 30–40% compared to traditional building systems, depending on project complexity.
Does CLT reduce site labour?
Yes. Off-site manufacturing means:
- Fewer workers on site
- Reduced high-risk activities
- Shorter site programmes
- Lower labour costs
What skills are required on site?
CLT installation requires:
- Crane operations
- Trained installers
- Standard carpentry skills
XLAM provides a full installation service or can provide guidance to ensure smooth site execution.
How does CLT perform acoustically and thermally?
CLT offers:
- Good thermal performance
- Reduced thermal bridging
- Strong acoustic performance when paired with appropriate build-ups
Final performance depends on wall, floor and ceiling assemblies.
Can CLT be modified after installation?
Yes. CLT panels can be modified during and after construction, provided structural considerations are addressed.
What maintenance does CLT require?
CLT requires no unusual maintenance. Protection from prolonged moisture exposure is key, as with any building material.
Why choose XLAM?
XLAM offers:
- Local manufacturing
- African market experience
- Hands-on technical involvement
- Sustainable sourcing
- Early-stage collaboration
- Proven project delivery
We partner closely with design and construction teams to ensure project success.