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.
