Ridgeboards
The ridgeboard in a conventional framed roof is not so much a structural member as a setout member. It makes sure that rafter couples meet at a consistent height giving a horizontal ridgeline free from sags. Ridgeboards locate and stabilise rafter ends. Opposing pairs of rafters must not be staggered by more than their own thickness at either side of their ridge junction.
Full-length ridgeboards should be used wherever possible, however, ridgeboards may be joined using a scarf joint at the abutment of a rafter pair. Or, preferably, they should be nail-spliced using full depth fishplates on both sides of the ridgeboard.
