If one gets a new asphalt? shingle roof with 20-year Monsanto? shingles,
how long should it last? 20 years?
Mine is only 13 years old and has a small leak already. I can't see the
back half of the roof from the ground, but the leak is in the middle,
not by the chimney flashing.
I watched them put it on and they did a good job. They used famous name
shingles, though I can't remember if it was Monsanto, 3M maybe.

Should have said Baltimore. Sunny summers but not over 95 for more than
a dozen days a year.
No curling on the shingles I can see.



How do you know where the leak originates ?
Even if you see the drip location in the attic -
the actual leak could be above that point -
at a vent flashing perhaps.
It's time to have a professional go up and look.
Hand him a can of roof patch when he goes.
John T.