Surface-tension gutter guards are really a cover that allows the water to flow along the surface and flow into slots on the edge and into the gutter. But the surface-tension guards Consumer Reports tested had a hard time handling a severe downpour.
Other gutter guards are made of foam or brush and they're inserted into the gutter. None of the inserts Consumer Reports tested were good at keeping out debris, which can lead to clogging.
And some gutter guards are screens with big holes. But one from Raingo let debris in. And part of it actually collapsed into the gutter!
Which guard did work well? A plastic screen from Amerimax, model 85198. It's very good at keeping debris out and water in. And it's a Best Buy at just 30 cents per foot!
Consumer Reports says that it can pay to have someone install your gutter guards. It will cost roughly $100 to $500, far less than paying for a pro-installation system, which costs thousands of dollars.