Hello everyone again,

Recently I have been looking into the bolster block type of construction.

For those that are unfamiliar with the concept, a bolster or pillow is a block set on top of a post to bear a beam. There are a number of reasons to use a bolster block. It can shorten then span of timbers by supporting them out further away from the post (This is almost universal on the old bridges in the Canton of Bern where bolsters are used to lengthen the allowable span between support piers)
Another reason is to allow simplified joinery in the post connection, especially if two beams must come together at a single level above the post, if one is supported by a bolster the connection is not overly weakened

Most frequently, Bernese carpenters will use a bolster block to simplify the scarf joints needed in roof framing. In log building, bolsters are very commonly used allow the carpenters to make long purlin runs out of a number of short spans -the purlins in this case need only span the distance between 2 posts. This is especially important in the Simmental, where the houses are expanded along their ridge to house a barn under the same roof (inn contrast to the Frutigtal where the barn is placed along the gable beside the house). The use of bolsters allows shorter timbers, which makes more efficient use of the logs.

In log building it is common to place a bolster on top of a post with a stub tenon or a bridle joint, then fix the beam on top with a network of pegs. The scarf in the beams is often merely a butt-joint, or perhaps a tenoned scarf to resist twisting. Sometimes a pegged half lap is used. Complex scarf joints are deemed unnecessary (and this belief is supported by centuries-old examples)

bolsters are also used in the timber framing regions, especially in the regions where timber framing is intermixed with log building. In the north, on the Swiss Plateau, bolsters are far rarer. In this range, where the overall roof structure is a genuine timber frame, the assembly often includes let in braces attaching the bolster and the post.

I like bolsters. It is one of the many examples in the Canton of Bern where carpenters chose to adopt an incredibly simple solution to their problems rather than seeking to solve it with complex joinery and complicated truss assemblies. Timber framing here is full of this concept, and log building has taken this principle the furthest.