One of the rounded caps on the peak of the roof (far right in pic) blew off in the wind. A roofer came and put it back up for me and he said the whole length was cemented down with dobs of cement instead of bedded in the way he has done. He recommended lifting it all and bedding in the way he has done. My brother in law (not a roofer) said its a waste of money and to leave it. You can see in the pic where the guy has pointed several gaps along the length. I'm of a mind to get it done as the consequences of a crap roof are wild, varied and usually expensive.