When fixing my first few roofing battens I dutifully followed industry guidance and fixed the battens with 65mm x 3.5 nails driven in with a hand hammer. This did not feel right and I was concerned about splitting the battens at the ends. I quick stopped fixing battens within 300mm of a batten end to give me time to reconsider.   When visiting a large national chain of roofing supplies I asked what nails do the pros buy to fix battens. The unequivocal answer was "they all buy those 65m