Roof framing, exploded

Last week, Arron and I saw a neat roof framing detail at a Greek Revival home in Brunswick.  The rafter was joined to the tie beam with a birdsmouth and pinned with a trunnel, the tie overlapped the plate and supported a flying purlin, and the plate ran past the gable end post to create the overhang for the return.

Roof frame detail at return

There were areas that were badly deteriorated by critters and leaks, but the tie-plate joints were as tight as the day they were assembled.  The relish at the ends of the tie beams, after the birdsmouth, were all still intact, probably due to the work of the trunnel, pinning the rafter foot in place.  This was the first time I’d seen this particular joinery in a roof assembly; it’s always nice to see how well timber frame joinery withstands the pressures of weather and time.

Dimensioned roof detail, from gable