Actually, mortar is an 'adhesive' in that use, it's just separated from foam and other adhesives due to the vast differences in their properties, and the fact that mortar fails to bond at a relatively high rate when not done precisely, exactly, correctly, the right way.



That's the harder part, but basically - yes.

The newer code (which may apply, probably applies to that house) requires a ridge nailer, either wood or sheet metal. You've probably seen them being installed on newer roofs. Their sole purpose is to provide an anchor base for those fasteners for the hip and ridge tiles.



My guess would be that the fasteners *are* "required", but that the AHJ in your area is not yet, or was not then, aware of it. That does not make it "right", it just makes it "harder to get it done right" after the fact.

Call your AHJ and ask them how hip and ridge tiles are supposed to be attached. Tell them you've heard of, and seen, nailers being installed and the hip and ridge tiles are fastened to those nailers. Then ask if that is require there.

1) When they say 'Huh?', that's your answer.

2) When they say 'Yes, that's a new system.', that's your cue to ask 'OK, okay, when did you start requiring them here?' (you now have your answer).

3) When they say 'Yes, but we don't bother with that crap here.', that's also your answer.

2) is a good reply from them, 1) and 3) are not.