On 04/02/18 11:50, Harry Bloomfield wrote:
Simon T wrote on 03/02/2018 :
http://www.clipsfromthecryptserver1.com/temp/tile1.JPG

Not very much overlap there at all. My roof has three thicknesses of
tile over the entire roof. Loose one tile and it would make absolutely
no difference to weather ingress.

Lucky you spotted it in time to prevent major damage.

Those pantile style tiles don't have 3 overlaps - but it should be more
than shown...