The earliest substantial timber-framed houses were built
using the cruck-truss method. A cruck was a naturally curved timber, cleaved
into two to give a matching pair. They were joined at the top, giving a shape
like an upturned boat, and supported the weight of the roof. The
non-weight-bearing walls were then less liable to collapse. A horizontal sill beam, the most substantial timber in the building, supported the entirety of the structure. The sill was set on a plinth of stone or brick to counteract the damp.
Crucks explain the popular but erroneous belief that houses were built with reused ship's timbers. This may have happened in coastal areas – wood was too valuable to be wasted – but would have been hopelessly impractical for inland settlements.
A cruck framed house. With thanks to Peter Foster.Crucks explain the popular but erroneous belief that houses were built with reused ship's timbers. This may have happened in coastal areas – wood was too valuable to be wasted – but would have been hopelessly impractical for inland settlements.
Crucks were followed by the box-frame method, of which examples abound in Preston.
Substantial timbers were used in each wall, which now carried the weight of the roof. More skill was needed to prevent the walls' collapse. Tie beams linked the opposite walls and prevented them splaying outwards. In earlier houses, 'arch bracing' (diagonal timbers) added stability.
Quality timber came from mature trees, several hundred
years old, and in demand for ship-building, fuelling furnaces and other
industrial processes. By the 18th century, there was now little left for building.
The timber-frames of the 18th
century were built with poorer quality timber – often softwoods instead of oak
– and thin planks of little structural benefit were used. This was short lived:
within a few decades, a new building method, entirely using brick, was adopted.
No comments:
Post a Comment