What is a sleutelstuk?
A sleutelstuk (Dutch, literally “key piece”) is a flat horizontal timber fixed under the end of a beam, usually a main beam or summer beam, and supported in turn by a brace and a wall post standing against the masonry. It is typical of historic Dutch houses. There is no exact English equivalent: the closest terms are timber corbel and bolster, a horizontal cap on a post that shortens the span of the beam above.
How it works
- A rigid triangle. Wall post, brace and sleutelstuk form a triangle that cannot rack, stiffening the joint between beam and wall.
- Load path. The sleutelstuk projects from the wall under the beam and supports it in front of the wall face. Loads travel through brace and post into the masonry.
- Both ends. Main beams often had one at each end.
- Decorated. Many are moulded, hollowed or carved, and even the timber pegs fixing them to the beam could be decorative. Sometimes the brace is curved so it projects less into the room.
Not the same as a corbel or console. A stone or timber corbel is a single bracket working on its own. A sleutelstuk is always part of a timber assembly with post and brace; an old one reused without them effectively becomes a corbel.
Application in repair and renovation
- Keep the assembly intact. Removing a brace or post to gain space takes the stiffness out of the structure. Have any change checked by a structural engineer.
- Inspect beam ends. Decay often starts where beam and bracket sit in or against damp masonry. Probe for soft timber with a bradawl.
- Repair selectively. Replace only decayed parts and agree the method with an experienced carpenter or conservation specialist.
- Check the building’s status. In the UK, work affecting the character of a listed building needs listed building consent.
- Record it. Photographs and measurements of mouldings help repair and building history research.
Related terms
- Corbel
- Summer beam
- Timber brace
- Post
- Beam end
- Console bracket
- Summer beam repair
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