What is a strijkspant?
A strijkspant (Dutch) is a frame in a roof structure that runs more or less parallel to the roof plane. That is how the Dutch building reference by Joost de Vree defines it. On its purpose the same source is cautious: it probably served to stiffen the structure. There is no fixed English equivalent. The name echoes the strijkbalk, the joist that runs alongside a wall: strijken means to pass along something, and this frame likewise runs along rather than across.
The term belongs to Dutch building archaeology and appears mainly in studies of historic church and town-house roofs. Examples mentioned in the literature include:
- the reconstruction of the 17th-century roof of Rapenburg 23 in Leiden;
- a strijkspant in the west gable of the Dutch Reformed church at Rockanje;
- the south roof of the ambulatory of the Oude Kerk in Amsterdam, dendrochronologically dated to 1559, which according to roof historian Herman Janse has a strijkspant carrying carpenters’ assembly marks.
The sources give no general, precise definition and no standard dimensions. Treat the word as descriptive: it is used in reports on a particular roof.
In practice
- Read the building survey. If a report mentions a strijkspant, check the drawings to see exactly which member is meant.
- Do not remove it without advice. Even if its role is unclear, the frame may add to the stiffness of the roof. Involve a structural engineer experienced with historic roofs.
- Record assembly marks. Cut marks on frames show the order in which the roof was assembled. Document them before dismantling anything.
- Check heritage consent. Roofs of listed buildings are often protected, and alterations usually need permission.
Common mistake: writing off an oddly placed frame as a later addition and taking it out. It may be an original stiffening member.
Related terms
- Roof truss
- Roof structure
- Gable end
- Purlin
- Steekspant
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