Like other joints of its kind, a half-lap scarf joint is used to join two timbers end-to-end to span a length greater than the lumber at hand. The half-lap is probably the simplest of all the scarf joints to cut, as it is merely two timbers reduced to half of their thickness where they lap over each other. This provides a face-grain-to-face-grain joint with plenty of connecting surface. The joint is usually secured with screws or pegs.
This is my kind of joint: dumb simple.
Are there any limitations for its use, in terms of timber size or span? For instance, I’m wondering if it can be used for a 24′ long tie beam in a 24’x36′ garage/workshop.