Is this a recognised method of fixing or a cowboy repair?. I have a couple of Velux windows in my roof and i noticed that the tiles that were trimmed to fit around the windows did not have any Nubs to locate over the battens. I informed the contractor about my worries that the half tiles could possibly slip out. They came and fixed the problem by placing a few blobs of resin/cement between the vertical interlocking joints of the half tiles and the adjacent whole tiles. As far as i am aware the adjacent whole tiles are not mechanically fixed to the battens. Could any roofing experts out there please tell me if this method of glueing is acceptable or a cowboy lash up. Many thanks.