I'm making bird houses and I have been screwing the joints together. I have been drilling a pilot hole (2mm bit) and using 3mm X 30mm screws.
I hung one in my garden and noticed that a couple of joints appear to be coming apart slightly after around a month or so. The houses are finished with Cuprinol Shades outdoor paint and the wood is bare before I paint (no primer etc).
Is there a more effective way of joining end grain to prevent warping/movement? Would gluing the joints, using larger screws, a smaller pilot hole or priming the wood first help to prevent this? The joints are 30 and 45 degrees.