I can see how dap would be applicable. The surface of the water is just broken, and the surface of the rafter is just broken, a dap.
On a road trip today I stopped at 3 barns, the first 2 no one home and the third someone was there and happy to have the barn looked at. It was a mutt, mixed with older/used timber, mortices in crazy spots, scarf joints, and English top plates used as principal purlins put in up side down exposing the dovetails to below. These were matching plates about 40' long with scarfs extending to about 60'. It had a queen rod truss as the second bent, I'm guessing to allow the animal to swing around as they came in the gable end door. Still no CG's.
