Archive for July, 2014

The Lightning Scarf‏

When purlins meet on the principal rafter, the timber framer needs to find a suitable joint that strikes the right balance – take too much out of either structural member and the roof might fail. No pressure there then….

The lightning scarf can be a good choice if the purlins are trenced down onto the principal rafters. It’s a classic scarf – a means of joining one timber to another along their length, and of course it’s also an opportunity not to be missed to show off with a bit of snazzy carpentry.

Here are a shoal (collective term?) of lightning scarfed purlins waiting for assembly in the workshop, and one joint temporarily pinned with podgers.

Double Jowl

A post with a single “jowl” is a fairly common occurrence in timber framing (see our very first blog post about the English > Tying Joint ) but a double jowl? Does such a thing exist?

Well yes, although a rare and secretive species, double jowls have been spotted this side of the Welsh border. Usually found in small groups, here we have an example of 5 double jowl posts cosying up to each other.

The upper jowl or flare is designed to allow a tenon to insert into the tie beam whereas the lower jowl’s purpose is to add bearing support to a heavy floor beam. It also of course adds some beautiful curves to the whole structure which is never a bad thing.

If anyone ever comes across a triple jowl, please send me photographic proof!

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