Product · Structural Systems
Product · InnDex 68 · Evidence provided · High specification risk
Mass timber panels with biaxial strength and fire resistance for mid-to-high-rise structural frames.
CLT panels are factory-laminated solid wood sheets that provide load-bearing capacity in two directions, enabling mid-rise and tall timber structures. It addresses the embodied carbon intensity of concrete and steel framing while maintaining seismic and wind performance. Fire safety is achieved through char layer formation rather than active protection, and research from ETH Zurich and Arup validates structural behaviour in buildings up to 18+ storeys.
CLT panels are factory-laminated solid wood sheets providing biaxial load-bearing capacity, enabling mid-rise and tall timber structures that deliver a 40–75% embodied carbon reduction versus reinforced concrete frames while achieving seismic and wind performance validated in real buildings up to 18-plus storeys through ETH Zurich and Arup research programmes. Factory fabrication reliably compresses on-site programme and reduces waste, and the char-layer fire resistance mechanism is well understood without requiring active protection systems — these are genuine performance points, not marketing claims. The honest constraints sit in cost and code: CLT at premium pricing versus concrete and steel has not yet reached parity in most markets, and building regulations remain fragmented by jurisdiction with codes still evolving, which adds programme risk on any project requiring building control sign-off from a less-experienced authority. Acoustic performance between storeys requires additional treatment layers not needed in concrete framing, adding design complexity and cost that is not always captured in early-stage timber-versus-concrete comparisons. CLT manufacturing capacity is also genuinely constrained outside Europe — supply chain in North America and most of Asia cannot yet absorb rapid market scaling, which affects lead times and cost certainty on large projects. For a design team on a sustainability-led mid-rise project in a jurisdiction with maturing timber codes, this is a well-evidenced structural option; for a fast-track project in a market with immature supply and limited regulatory precedent, the programme and cost risks require careful stress-testing before concept commitment.
Strong empirical track record in EU (Metsä Wood, Katerra projects) and growing North American deployment (Telus Garden, T3 Minneapolis). ETH Zurich and Arup research on structural performance and LCA widely cited and peer-reviewed. However: (1) fire rating claims rely on prescriptive char models—full-scale compartment fire data is limited; (2) seismic validation mostly finite element; real seismic performance in high-rise CLT still limited (few >10-storey buildings in seismic zones tested post-event); (3) carbon payback period and supply-chain sourcing claims vary widely (40–75% range is real but context-dependent on region, concrete baseline, transport, and reforestation assumptions); (4) cost parity claim not yet universal—CLT remains 10–20% premium in North America, though EU pricing has narrowed; (5) long-term durability (>50yr) and moisture ingress/creep under sustained load not fully documented in service. Arup link provided; ETH work is published but not exhaustive for all building types.
#mass timber #embodied carbon #biaxial loading #fire performance #tall timber #prefabrication