Mass Timber Connection Design

Connection Engineering for Glulam, CLT, and Mass Ply — Where Structure, Fire, and Beauty Meet

Mass timber is having its moment, and for good reason: it goes up fast, it sequesters carbon, and an exposed timber structure is something people actually want to stand inside. But mass timber doesn’t forgive the way steel and concrete do, and nowhere is that truer than at the connections. Wood behaves differently — it splits, it shrinks, it moves with moisture, it carries load along the grain very differently than across it. A connection detail that would be routine in steel can crack a glulam beam or compromise a panel if the engineer doesn’t understand how the material actually wants to behave. At Lam-Wood Systems Inc., our licensed Professional Engineers design mass timber connections that respect the wood, satisfy the code, hold up to fire requirements, and preserve the clean look that made the client choose exposed timber in the first place.

Connections are the hardest part of mass timber engineering, and they’re where projects most often go wrong. The members themselves are increasingly well understood, but the joints have to do several demanding things at once: transfer significant loads through an anisotropic material, account for wood shrinkage and movement, meet fire-resistance requirements that often mean concealing steel inside the timber, and frequently stay invisible so the beauty of the structure isn’t broken up by clunky hardware. Balancing all of that takes engineers who genuinely understand wood — not engineers applying steel logic to a material that doesn’t play by steel’s rules.

What We Design

Mass timber connections span a range of members, materials, and conditions, each with its own demands. Our team engineers the full scope, matched to the specific timber system your project uses and the performance it has to deliver.

Beam and Column Connections. The primary load-carrying joints of a timber frame — beam-to-column, column-to-column, beam-to-beam. We design these connections to transfer heavy gravity and lateral loads through glulam and heavy timber members while managing the splitting and bearing stresses that wood is uniquely prone to.

Concealed Connections. When the architect wants the timber to read as clean, uninterrupted wood, the steel has to disappear. We engineer concealed connections — knife plates in routed slots, hidden hangers, internal hardware — that carry the load out of sight, preserving the exposed aesthetic that justifies building in timber at all.

Panel Connections for CLT and Mass Ply. Panelized mass timber — CLT, and Mass Ply products like those from our partner Freres Engineered Wood — connects panel-to-panel and panel-to-frame in ways that demand their own detailing logic. We design the splines, brackets, and fasteners that tie panelized floor, roof, and wall systems together into a working diaphragm.

Fire-Engineered Connections. Exposed mass timber has to meet fire-resistance ratings, and connections are the vulnerable point — exposed steel loses strength fast in a fire. We engineer connections that meet code fire requirements through char-layer design, concealment, or protection, so the structure performs under fire as well as it performs under load.

Steel-to-Timber Connections. Where mass timber meets a steel frame or steel components, the joint has to work across two very different materials. Because we engineer both sides, these hybrid connections are a particular strength — more on that below.

Engineering That Actually Understands Wood

The difference between a mass timber connection that works and one that fails often comes down to whether the engineer truly understands the material — and not every structural engineer does. Wood is anisotropic, meaning it behaves differently along the grain than across it. It shrinks and swells with moisture. It’s strong in some directions and prone to splitting in others. Bolt patterns that ignore these realities can initiate cracks that propagate over time. Connections that don’t allow for shrinkage can build up unintended stresses as the building dries in. Designing mass timber connections well means designing for the wood, not in spite of it.

That understanding is exactly what Lam-Wood brings. We’ve spent years supplying and detailing glulam, heavy timber, CLT and mass plywood panels, and the custom steel hardware that joins them. We know how these members are manufactured, how they behave, and how they move — because we’ve been on the material side of mass timber, not just the calculation side. When we engineer a connection, it’s grounded in how that specific glulam beam or mass timber panel actually performs in a real building. Every design is stamped and sealed by a licensed Professional Engineer.

Where Timber Meets Steel — and Everything Else

Mass timber projects are rarely pure timber. They mix steel frames, steel connections, and hybrid conditions throughout — and the joints between materials are exactly where uncoordinated engineering causes problems. This is where doing it all under one roof becomes a real advantage. The same team that designs your timber connections also handles the Steel Connection Design on the other side of a steel-to-timber joint, so both halves are engineered to work together instead of being negotiated between two separate firms. Once those panels and members are connected on paper, getting them safely into place is the job of our Mass Timber Lifting Design team. And when a connection question surfaces during erection, our Construction Support Engineering service turns a stamped answer around fast.

Designing both sides of a steel-to-timber connection is something most engineering firms can’t offer, because most don’t have deep expertise in both materials. We do — and for a mass timber project, that coordination is the difference between a frame that goes together cleanly and one that fragments into a coordination headache.

Who We Work With

Mass timber fabricators and suppliers rely on us for connection designs that are buildable, sealed, and detailed for production. General contractors and construction managers bring us in to handle the most technically demanding part of a mass timber build. Architects partner with us when an exposed timber structure has to stay beautiful without compromising on structure or fire performance. And developers choose us because mass timber is still new enough that genuine connection expertise is hard to find — and getting it wrong is expensive. Whoever’s building in timber, we make the connections work.

Engineer Your Mass Timber Connections With Lam-Wood

Mass timber’s connections are its hardest engineering problem and its highest-stakes detail — structurally, aesthetically, and for fire. With licensed Professional Engineers who genuinely understand wood, the ability to engineer both timber and steel sides of any joint, and years of hands-on experience with the actual materials, Lam-Wood Systems Inc. delivers connection design that lets you build in mass timber with confidence. This is part of our full structural engineering practice. Contact our engineering team or call 303-458-1736 to get your timber connections engineered right.