Traditional timber assemblies
Mortise and tenon, dovetail, and combing — joints that hold without nails
A timber connection must transfer forces from one piece of wood to another without giving way. Traditional connections solve that task by shaping the wood itself so it locks together — often supplemented with a wooden peg or a wedge rather than nails and metal brackets. Even though modern construction largely uses nails and metal brackets, the old connections are still alive in restoration, timber framing and visible timber.
§Tap og hul
The mortise and tenon joint is the very basic form. A protruding piece — the tenon — is cut on the end of one piece and fitted down into a corresponding hole (mortise) in the other. The joint provides a large gluing surface and a mechanical locking that absorbs both compression and tension when secured with a wooden peg. It is used in timber framing, door frames, frames, and everywhere two pieces meet at an angle.
§Half-lap, combing and scarfing
- 01Half-lap joint — the two pieces are cut so they overlap with half thickness each and form a flat surface; used among other things for joining lengthwise and at crossing timber
- 02Combing — a notch (a comb) is cut so a beam layer or rafter foot can rest stably on a strap without slipping
- 03Scarfing — a long slanted joint that extends timber in the length direction and distributes the load over a large surface
- 04Over-scrape — a cut where two pieces lock together across
§Why learn them today?
Although a modern carpenter rarely cuts mortise joints on a new villa traditional joints are still an important part of training. They train precision understanding of forces in wood and the ability to work to measurements and marking in the millimetre class. And in the restoration of protected and heritage buildings they are a direct requirement: here new timber must be assembled in exactly the same way as the old.
| Assembly | Direction | Typical use |
|---|---|---|
| Tap og hul | Angle | Timber framing, frames, surrounds |
| Half-lap joint | Længde/kryds | Extension, crossing timber |
| Combing / notching | Vinkel/vandret | Beam and rafter on ledge |
| Scarfing | Length | Extension of beams and straps |
§Craftsmanship and precision
Common to traditional joints is that they only hold if executed precisely. A loose tenon or a crooked planing gives a weak joint, regardless of how neat it looks from the outside. Therefore, marking, saw and mortise chisel are still basic tools, and the ability to cut a tight, load-bearing joint is one of the characteristics that distinguishes a skilled carpenter from a routine installer.
“The good assembly is not seen — it is felt when the structure stands as tightly a hundred years later as it did the day it was erected.”