I had a roofer come down to replace an attic fan, and while he was at it I asked him to replace various (asphalt) tiles which had come down in recent storms, or any others that he thought needed replacing.
Day beforehand, I was discussing it with my brother who is a real estate guy, and he told me that a very experienced property owner/manager we know had once told him he had never replaced a roof ever, in decades of owning and manging numerous properties. He believed in the long run it’s cheaper to constantly repair things than to redo the entire roof.
Interesting thing was that the roof guy’s numbers were in line with that. After he went up on the roof he told me that he thought I should probably get a new roof (over the current layer). Cost: $5,000. (I actually thought that was pretty cheap, FWIW.) So I said what about just replacing any tiles that currently need replacing, and he said $200. I think to myself that if an average roof lasts 25 years, pushing the $5K off by even one year at a cost of $200 is a worthwhile proposition, so I just went with the $200 option.
But that would tend to suggest that my property manager friend might be right.
(It’s possible that the roofer would have charged me more than $200 if he wasn’t up there installing a fan anyway, but I don’t know. Truth is that his initial quote for the fan itself was $375-$400, and he ended up charging me only $550 for the fan plus tiles, so I think there may have been some savings in there, and the $200 may have been the nominal price.)