Why we still use mortise-and-tenon: a defence of slow joinery

If you cut a Flamingo Westminster armchair in half — the test is theoretical, please don't — you'd find the frame held together with mortise-and-tenon joints. Square holes cut into one piece of timber, matching tongues cut on the other, glued and pegged into place. The same joinery the Egyptians used; the same joinery a mid-eighteenth-century English chair-maker would have used; the same joinery we still cut by hand on most of our frames today.

Most modern furniture doesn't use it. Dowels are faster. Biscuits are faster. Cam fittings are faster. Pocket screws are faster. Production lines that need to ship a thousand pieces a week have very rational reasons not to use mortise-and-tenon. We're not on a production line, and our reasons for sticking with the older method are equally rational. Here they are.

What mortise-and-tenon actually does

A mortise-and-tenon joint resists pull-out, twist, and shear simultaneously. The tenon (the protruding piece) sits inside the mortise (the cavity) on three faces — top, bottom, and one side — so the joint can't pull straight out, can't rotate, and can't sliding-shear. Glue holds the fourth face. With a peg or a wedge, the joint becomes mechanical, not chemical — even if the glue fails over decades, the wood-on-wood contact carries the load.

Most modern joints — dowels especially — rely heavily on the glue. A doweled joint is two pieces of wood with a couple of round pegs floating in glue between them. When the glue fails (which it does over time, especially in humid climates), the joint loses most of its strength. Mortise-and-tenon doesn't.

Why this matters in Bengaluru

Glue is the weak point of any furniture joint, and it's especially weak in humid climates. Bengaluru's monsoon takes the city to ninety percent humidity for three months a year. PVA wood glue — the standard adhesive — softens at that humidity. After ten or fifteen monsoons, doweled joints start to creak. Cam-fitted joints loosen. Mortise-and-tenon joints, with their wood-on-wood mechanical interlock, don't.

We've serviced enough decade-old pieces — both ours and our competitors' — to see the difference firsthand. Our oldest Westminster armchairs, from 2007, are still joint-tight. Equivalent doweled-frame chairs from the same era usually need joint repair by year ten.

What it costs us

A mortise-and-tenon joint takes about twelve minutes to cut and fit by hand. A dowel joint takes about two. On a typical armchair frame with sixteen joints, that's roughly three hours of additional labour. Across a workshop, it's the difference between shipping forty frames a week and shipping seventy. We do forty. The price difference shows up in the quote — and we're transparent with clients about why.

Slow joinery is not nostalgia. It is the difference between a chair that lasts ten years and a chair that lasts a hundred.

When we don't use it

We're not religious about it. Our hospitality and corporate fit-outs use cam fittings and biscuits where the use-case calls for it — modular workstations, knockdown cabinetry, anything that needs to be assembled and disassembled on site without a workshop crew. The joint type follows the brief; the brief doesn't follow the joint.

Where we always use mortise-and-tenon: residential frames meant to last decades, signature collection pieces, anything carrying a substantial seated load, anything we expect to service in year fifteen or twenty.

What this means for a buyer

If you're commissioning custom furniture and you care about how it ages, ask the maker about joinery. Specifically: "Are the frame joints mortise-and-tenon, dowel, biscuit, or cam-fitted?" Most reputable makers will tell you honestly. Most factory pieces — even expensive-looking ones — are dowel or cam-fitted. Both are valid choices for the right context; just know what you're buying.

The signature collections at Flamingo all use mortise-and-tenon for the structural frame. Our custom furniture service page has more detail on the construction methods we use across the bench.