Roof maintenance has a reputation for being either expensive or dangerous, which is why most homeowners skip it entirely. In practice the two checks that matter take twenty minutes and both happen with your feet on the ground.
The autumn check
The first is in autumn, once the leaves are down. Clear the gutters, then watch where the water goes during the next heavy rain. Overflow at a joint or a stream running down the fascia tells you more about your roof than any photograph will.
The spring check
The second is in spring, after the worst of the weather. Walk the perimeter with binoculars and look for lifted shingles, exposed nail heads and anything sitting at a different angle than it did last year.
What to do if a check turns something up
Most of what you will find is small, and small things are cheap while they are still small. A lifted shingle refastened in spring costs almost nothing. The same shingle after a winter of water running under it is a decking repair.
Take a photograph, note the date, and get it looked at before the next wet season rather than after it.
Write down what you see
Write down what you see, with a date against it. A photograph from last spring is the fastest way to prove a shingle moved rather than arguing about it later.
If both checks come back clean two years running, your roof is doing its job and you can leave it alone.
