I will keep my comments specific to commercial roofing such as flat rubber and metal roofing because that is our specialty.
Twice a year, typically Spring and Fall. A visual walk on should be done. Things to look for starting on one side and walking in a criss cross pattern. First check all the metal flashing for popping fasteners and mark with chalk. Working your way into the field of the roof, stop and check all roof penetrations like vents and pipes. What you are looking for is any cracking, separations or even holes. Mark all with chalk. Now fully into the open field of the roof walk slowly along ALL seems and look for ‘fish mouths” which appear to look like little openings and mark.
Now with all your markings in place time to take action.
First attempt to re-fasten all popping fasteners if unable to re fasten then cover tape might have to be removed introduce new fasteners then install new cover tape and primer.
Second any roof penetration marked should be cleaned and then apply a flashing grade roof coating or mastic also a polyester roofing cloth should be embedded then a second layer of roof coating or mastic.
Third any seems that were marked must be clean and dry and address same as roof penetration.
Keeping a regular roof maintenance and inspection schedule is imperative to a problem free roof.
If you have a roof that you would like a professional inspection done on a regular basis we can help. Contact us for details.