Essay
Mass Timber After the Hype
A decade into the timber revolution, an engineer’s audit of what actually worked, what quietly failed, and when to still choose concrete.
Aiko Tanaka — February 2025 — 9 min read
Ten years ago mass timber was going to end concrete. Today the picture is more useful: CLT floors perform brilliantly in repetitive residential grids; glulam frames excel where spans meet prefabrication; and certain typologies — wet, tall, acoustically demanding — remain stubbornly better in mineral materials. Maturity means knowing which is which.
The failures we have audited share a pattern: timber specified for image, detailed by teams without moisture management experience, protected by envelopes designed for masonry logic. Wood does not forgive sloppy detailing; it documents your mistakes in colour changes you can read from across a street.
Where we now specify timber confidently: housing frames on repetitive grids, pavilions assembled by hand, interior insertions within existing shells. Where we hesitate: ground-contact conditions, high-humidity pools and baths, and projects whose maintenance culture is unknown. Honest engineering includes declining commissions.
The carbon argument remains real but must be counted whole — harvest cycles, transport, adhesives, end-of-life. Our current projects average a 38% embodied saving against concrete equivalents, not the ninety per cent of conference slides. Truthful numbers build more trust than hopeful ones.
Timber is not a religion. It is a material with a moisture content.