What we saw → Overflowing gutters
Overflowing gutters
What it looks like
- Water sheeting over the front edge of the gutter during a rain instead of running to the downspout.
- Leaves or plants sticking up out of the gutter.
- Dark streaks down the outside face of the gutter.
What causes it
- It only takes a leaf and a stick to block a gutter and have that gutter fill with water.
- Once it blocks, any other debris that falls in during the rain goes down to that hole and blocks it even more.
- Too few downspouts — the gutter overflows in a hard rain no matter how well it’s hung.
- Pitch that’s off, so the gutter holds standing water instead of draining.
- A gutter hung too low under the roof edge, so water overshoots it in heavy rain.
What it leads to
- When a gutter overflows, it also backflows — water goes backward toward the house, not just over the front.
- Backflow wets the fascia board. Depending on how much water, it works its way into the roof decking and migrates upward.
- When the temperature drops at night, condensation forms and drips onto the attic insulation. Wet insulation packs down — eight inches ends up about two, and it stops doing its job.
- Water pouring over the front lands in one line at the foundation, erodes the soil, and that leads to basement leaks.
It happened to my own house. My gutters were cleaned every two months and still filled with debris, and the roof decking had to be replaced the entire length of the house, front and back. The whole story →
How we fix it
- Keep the debris out. The Valor Gutter Guard keeps leaves, needles and nests out of the gutter, so there’s nothing to clog.
- Seamless .032 aluminum gutters, pitched toward the outlet, with enough downspouts for a hard rain. See gutters.
Questions and answers
Why do gutters overflow?
Most often, debris. It only takes a leaf and a stick to block a gutter and have it fill with water, and every rain after that packs more debris into the same spot. Too few downspouts, pitch that’s off, and a gutter hung too low under the roof edge also cause overflow.
Does it matter if my gutters overflow once in a while?
Yes. An overflowing gutter also backflows toward the house, wetting the fascia board and working into the roof decking, and the water that goes over the front erodes the soil at the foundation.