Why Are My Gutters Overflowing in Heavy Rain?

Look while it is raining

A dry gutter hides almost everything. You cannot see a clog from the lawn. You cannot see a gutter that has lost its slope. In a downpour, all of it shows.

So the next time it pours, go and look. Stand in the yard with an umbrella, or look out an upstairs window. Walk the whole way around the house.

Stay off the ladder. Wet rungs and a wet roof are how people get hurt. Everything you need to see is visible from the ground.

Take a short video on your phone while you are out there. Twenty seconds of the water tells a gutter company more than any description can.

Where the water comes out, and what it means

Match what you see to the first column.

It spills over all along the front

This is the most common one by far, and the good news is that it is the cheapest. The gutter is full, or the downspout is plugged and the gutter has backed up behind it.

Fall makes it worse fast. The leaves are only starting to drop, and one storm can pack a gutter that was clear a week ago. Near pines, the downspout usually clogs before the gutter does. Why needles do that.

The fix is a proper gutter cleaning: debris out by hand, and every downspout flushed until the water runs through.

It spills at one spot

A gutter needs a slight slope toward the downspout. Home inspectors look for about 1/16 inch of drop for every foot. When one stretch sags, water collects in the low spot and spills there, even when the gutter is clean.

On older houses, the cause is usually the long nails the gutter hangs on. They work loose a little every winter. Look for a row of nail heads sticking out of the front of the gutter.

This is the repair we do most. We take the nails out and rehang the gutter on hidden hangers that screw into the board behind it, with the slope set right.

It shoots past a corner

Look up at the roof above that corner. If two slopes of roof meet there, they pour a lot of water into one short piece of gutter, and it arrives fast.

The usual answer is a splash guard. It is a small piece of metal on the corner that catches the water and turns it back into the gutter. It is a small fix, not a new gutter.

It runs down behind the gutter

This one matters most, because you cannot see the damage it does. The water runs straight down the board the gutter hangs on. A season or two of that and the wood goes soft.

Usually the gutter has pulled away from the house or was hung too low. Sometimes the roof edge stops short of the gutter and water finds the gap. We rehang the gutter, and replace any soft board first. New hangers in rotten wood pull straight back out.

It drips from a corner, an end or a joint

Even a seamless gutter has joints at the corners, the ends and where the downspout drops out. The sealant there wears out with time. A clean, dry reseal usually lasts years.

If that joint has been patched again and again, the metal behind it may be worn through. Then we quote replacing that stretch of gutter rather than patching it one more time.

Nothing much comes out of the downspout

If the gutter is full but the downspout is barely trickling, the plug is inside it. It is usually packed at one of the bends.

Poking a stick down from the top tends to pack it tighter. It needs clearing from the bottom as well. If the downspout runs into a pipe underground, the clog can be in that line instead, and it needs clearing through to where it comes out. We do that too.

When clean gutters still overflow

First, some overflow in a big storm is normal.

In an average year, Red Bank gets rain falling at just over four inches an hour for a few minutes at a time. In a bad storm it reaches seven.

A steep roof makes it worse. The engineering guide used to size gutters warns that water off a steep roof can move fast enough to overrun the front edge. So for a few seconds at the peak, a perfectly clean gutter can spill.

What is not normal is clean gutters overflowing in steady, ordinary rain. Then the gutter is too small for the roof above it, or there are too few downspouts.

Sometimes one corner is doing all the damage. A splash guard, or a bigger downspout at that spot, can be enough. We will look at the water first and tell you which.

If the whole house needs bigger gutters, that is a full installation, and it is a job we do not take on. We will tell you so on the first visit, rather than sell you repairs that cannot fix it.

If you have gutter guards

Guards keep leaves out of the gutter. They do not stop leaves landing on top. When that layer builds up, rain runs across it and off the front, and the gutter underneath stays spotless.

So if water pours over your guards, the guard needs cleaning, not the gutter. If it keeps happening, the type of guard may be wrong for your trees.

Fine mesh is the type most likely to do this. Here is why, and here are the guards we install.

Water in the basement after heavy rain

Walk to the bottom of each downspout. If it lets the water out right against the wall, that water can soak straight down beside your foundation.

Home inspectors say to carry it four to six feet away, onto ground that slopes away from the house. The U.S. Department of Energy says at least five. A downspout extension from the hardware store is often enough.

If the downspouts drain well away and the basement still gets wet, the problem is not your gutters. It is usually the slope of the yard or the foundation itself, and that is a job for a waterproofing company.

What it costs to fix

A blockage is a cleaning. Ours typically run about $200. What decides the price.

Rehanging a sagging stretch, resealing joints or clearing a stubborn downspout is a repair. Most of ours come in between $200 and $500. It runs higher when there is rotten board to replace behind the gutter.

Either way, you get the price before we start, and it is the price you pay.

Overflowing gutters FAQ