**A top-beam frame is a timber frame in which a horizontal beam (the top beam, Dutch dekbalk) rests on top of two vertical posts and is jointed into them.** It is one of the main forms of the traditional Dutch and Northwest German hall-house bent and is found in roof structures of hall-houses, barns and older byres, alongside the related anchor-beam frame.
Construction
A top-beam frame consists of three main parts:
- Two posts — the vertical load-bearing timbers
- One top beam — the horizontal beam spanning over the posts
- Braces (korbelen) — diagonal struts between post and top beam for stiffness
Joints are usually mortise-and-tenon secured with timber pegs. By placing the top beam over the posts, a shorter bearing point is created for the roof structure.
Difference from the anchor-beam frame
The main difference lies in the position of the horizontal beam:
| Type | Position of the horizontal beam |
|---|---|
| Anchor-beam frame | Passes through the posts at mid-height |
| Top-beam frame | Rests on top of the posts as a capping |
| Head-beam frame | Tenoned into the top of the post |
In the anchor-beam frame the posts continue up past the beam; in the top-beam frame they stop under it.
Application
The top-beam frame is found in:
- Hall-houses in the east and north-east of the Netherlands and in Northwest Germany
- Barns and byres built between the 17th and 19th centuries
- Reconstructions of historic farmsteads
- Character new-builds with open halls and exposed timber bents
Pros and cons
The top-beam frame is straightforward to assemble and gives generous head height. The downside is lower lateral stiffness than the anchor-beam frame, so additional braces or wind bracing are needed.
Related terms
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