Franglais:
Is it possible that the OP could be on Domestic regs rather than EU regs?
It doesn’t seem clear what the nature of the truck driving is. Could be just transporting own gear/tools between nearby work sites? The driving appears incidental to main job, and 4 hrs could be within the 100km limit?
Good point, the OP did say he works in a timber yard so I would have thought it most likely that he’s on EU regulations … but we may never know for sure 