Warning: I almost paid $450 for new gutters before a neighbor in Marietta set me straight
Our gutters were overflowing bad every time it rained hard, and I was ready to just sign a contract for all new ones. A guy two doors down in Marietta told me to wait and check the downspout screens first. Turns out three of them were clogged with pine straw and one was pitched wrong, so water was pooling and backing up. Spent $35 on new screens at the hardware store and about an hour on a ladder, and the problem went away. I felt pretty dumb but also relieved. Has anyone else had a gutter guy try to sell them a full replacement when it was really just a clog?
Most of the time it really is just a clog, but I would push back a little on the screens thing. Those little downspout screens can actually make things worse in pine straw territory because they catch the needles right at the top and then the whole thing dams up even faster. I had that exact problem in a house with two big pines out front, and the screens were part of why it backed up. A better fix for pine straw is a good gutter guard or just cleaning them twice a year, or the strainer style that sits in the outlet and you can pop out easy. The pitched downspout part is real though, that one gets missed all the time.