Seamless gutters are gutters made from one continuous piece of metal, cut to the exact length of each side of your house. With no joints along the run, there are fewer places for water to leak out. The only joints left are at the corners and where the downspouts connect.
The short version
- A seamless gutter is shaped from a roll of flat metal at your house, so each run is as long as the wall it hangs on.
- Fewer joints means fewer leaks and fewer spots for leaves to catch.
- The corners and downspout connections are still joints, and they still need to be sealed well.
- A seamless gutter does not fix a gutter that is too small, too flat or hung on rotten wood.
- Seamless gutters in aluminum are what we install at Roofing NextGen Ellicott City.
How are seamless gutters made?
Seamless gutters are formed on site from a coil of flat metal. The crew feeds the coil through a machine that bends it into the gutter shape, and the gutter comes out as long as the wall needs. Installers fabricate and install seamless gutters on site (opens in a new tab) so they match the exact size of your house.
Ordinary sectional gutters come in short pieces that get joined end to end. Every join is a seam, and every seam is a place where sealant has to hold for years.
Are seamless gutters better than sectional gutters?
For most houses, yes, mainly because there are fewer joints to fail. Seamless gutters are less prone to leaks (opens in a new tab) than sectional ones because they have fewer joints. Fewer joints also means fewer ledges where leaves and grit pile up.
The trade-off is cost. Seamless gutter systems typically cost more (opens in a new tab) than sectional gutters, though you get less maintenance and fewer repairs in return.
| Seamless gutters | Sectional gutters | |
|---|---|---|
| Joints along a straight run | None | One at every join between pieces |
| Made | On site, to the wall length | In short pieces, joined end to end |
| Leak points | Corners and downspouts | Every joint, corner and downspout |
| Up-front cost | Typically higher | Typically lower |
Do seamless gutters still leak?
They can, at the corners and the downspout openings. Seamless gutters have joints only at corners and downspouts (opens in a new tab), and those joints can weaken over time.
The annoying part is that a leak at a corner often looks like a leak at the fascia, the board behind the gutter. If you see a drip stain or peeling paint under a corner, that joint is the first place to look. Resealing a corner is a small job. Letting it drip onto the wood for a few years is not.
What size should the gutters and downspouts be?
Size depends on how much roof drains into them, not on how big the house looks. A common rule is 1 square inch of downspout opening for every 100 square feet of roof (opens in a new tab) feeding it. A standard 2 by 3 inch downspout handles roughly 600 square feet (opens in a new tab) of roof, and a 3 by 4 inch one handles up to 1,200.
Slope and spacing matter just as much. Gutters are typically sloped about 1/4 inch for every 10 feet (opens in a new tab) so water runs to the downspout, and a run of 60 feet or longer should have at least two outlets (opens in a new tab).
Here is what we see most when a clean gutter still pours over the edge: it is too small for the roof, too flat, or short on downspouts. A seamless gutter built wrong overflows just like any other.
How far from the house should the water go?
A downspout should carry water at least 5 feet from the foundation. Building science guidance says to connect downspouts to piping that carries water 5 feet or more (opens in a new tab) from the foundation, or to an underground catchment at least 10 feet out.
Many Ellicott City lots slope, so the direction matters too. Water that leaves the downspout and runs straight back at the house has not gone anywhere. A corrugated plastic extension (opens in a new tab) attached to the downspout is the cheapest way to move it further out.
Cleaning, and the boards behind the gutter
Seamless gutters still fill with leaves. Fewer seams helps, but a gutter under an oak is a bucket waiting for its next load. Gutters should be cleaned at least once a year (opens in a new tab), and more often with trees close to the house. We clean troughs, downspouts and underground lines through our gutter cleaning service.
Standing water is what does the damage. A full gutter, or water wicking behind a gutter with no gutter apron, rots the fascia, then the rafter tails, then the first few inches of decking. You cannot see it from the ground or from the attic. Our article on fascia boards shows what to look for. When we put in new gutters, we check the boards behind the old ones for rot first.
Common questions
Are seamless gutters made of aluminum?
Most are. Aluminum is the most common choice (opens in a new tab) because it is light, rust resistant and cost effective, and it is the metal we install. Seamless gutters can also be made of copper.
Do I need gutter guards?
Ask when you call. Guards can cut down on cleaning under heavy trees, but no guard stops every leaf, and some make the gutter harder to clean when it does clog.
Can a seamless gutter be repaired?
Yes. Most sagging, leaking or loose gutters can be fixed by resealing, re-pitching or replacing the fascia behind them. Our gutter repair page covers what we fix. If the gutter is rusted through or too small, replacing it makes more sense.
Is a new roof a good time to replace gutters?
Yes. The roof edge is already open, so the gutters can be set correctly against the new drip edge. Gutters are not part of a standard roof replacement, so ask for them to be quoted with the job.
What to do next
If your gutters overflow when they are clean, sag, or leak at every joint, we will look at them for free as part of a roof inspection. Our gutter installation page explains what a new set includes: gutters and downspouts sized for the roof and pitched to drain.
