Residential roofing · Gutters
Gutter installation, replacement, and repair
A gutter is a drainage system, not trim. It gets sized for the roof area actually draining into it, pitched so it empties, and detailed so the water leaving the roof edge lands inside it instead of behind it. Most of the failed gutters we take down failed on one of those three points.
- CA Licence #1052777
- We price match like-for-like bids
- 5–10 years on labor and workmanship
What properly sized gutters get you
Why the sizing math matters
No overflow in a hard storm
Sized to the actual drainage area, not the size of the house, so the hardest hour of the storm does not overwhelm it.
A dry fascia
Correct drip edge and gutter position stop water from getting behind the gutter and rotting the board it hangs on.
Seamless means fewer leak points
Roll-formed to the exact length of the run, so joints only exist where they have to - at corners and outlets.
Water away from the foundation
Extensions and proper discharge keep concentrated runoff off expansive clay soil against the footing.
Gutters are sized for the roof, not for the house
The number that matters is the drainage area - the projected roof area that actually runs into a given length of gutter - not the square footage of the house and not what the builder happened to put up. Two houses of identical size can need completely different gutter systems depending on how the roof is cut up.
Three things drive the load on any one gutter run:
- How much roof feeds it. A single long eave collecting two roof planes and the discharge from a valley is carrying several times the water of a short eave under a simple gable.
- How fast the water arrives. Steep roofs deliver water to the edge quickly and with momentum. Slick surfaces - tile, metal, new shingle - deliver it faster than a weathered rough one.
- How intense the rain is. Not the annual total. The peak rate, for an hour, in the worst storm the system is expected to handle.
What the code sizes against
Roof drainage in California is sized off a design storm, not off habit. The California Plumbing Code sizes primary roof drainage - drains, gutters, conductors, leaders, and horizontal storm drains - on a storm of60 minutes duration with a 100-year return period, with location-specific rainfall rates tabulated in Appendix D, and it establishes a design rate for primary drainage rather than leaving it to judgment.
Most single-family gutter work is not plan-checked against that appendix. But it is the standard the trade sizes to, and it explains the important idea: the system is designed for the worst hour, not the average year. A gutter that is adequate for a typical December drizzle can be badly undersized for the storm it will actually be judged on.
Source: California Plumbing Code, Chapter 11 and Appendix D. Verified August 2026 - confirm current requirements with your building department on any permitted work.
Five-inch, six-inch, and downspouts
| Configuration | What it suits | Notes |
|---|---|---|
| 5" K-style with 2x3 downspouts | The residential default. Fine on modest roof planes with enough downspouts. | The most common thing we take down, because it was installed by area and by habit rather than by drainage area. |
| 6" K-style with 3x4 downspouts | Long runs, large or steep planes, valleys discharging into one run, tile roofs, and anywhere a second downspout is not practical. | Meaningfully more capacity in the trough and a much larger outlet. The upgrade cost is small next to the cost of chronic overflow. |
| Half-round | Historic and period homes where the profile matters - Spanish Colonial, Craftsman, Tudor. | Often the right aesthetic choice in San Gabriel Valley historic districts. Sizing math still applies. |
| More downspouts | Frequently the cheapest real fix on an existing system. | Outlet capacity is usually the bottleneck, not the trough. Adding a downspout can solve an overflow that a bigger gutter alone would not. |
Pitch, hangers, and the parts nobody looks at
- Pitch. Roughly a quarter inch of fall per ten feet toward the outlet is the working standard, and a bit more on a long run. Too little and the gutter holds water, breeds mosquitoes, and sags under the weight. Too much and it looks crooked against a level fascia line, which people notice immediately from the street.
- Hanger spacing. Water is heavy. A six-inch gutter running full weighs a great deal per foot, and hangers spaced for appearance rather than load are why gutters sag in the middle of a run and then never drain properly again.
- Spikes and ferrules. If your gutters are hung on spikes driven through the face into the rafter tails, they will work loose. Hidden hangers screwed into sound fascia hold far better and do not leave a row of rusting holes across the front of the house.
- Position relative to the roof plane. The gutter has to sit where water leaving the roof edge lands in it - low enough to clear sliding snow or ice where that applies, high enough and close enough that fast-moving water off a steep plane does not simply shoot past.
- Outlets and corners. The joints that exist by necessity. These get sealed properly or they leak, and they leak directly onto the fascia.
Why undersized gutters fail in an atmospheric river
Southern California does not get its rain evenly. Atmospheric rivers - narrow corridors of concentrated water vapor coming in off the Pacific - account for a large share of coastal Southern California’s annual precipitation, research generally putting it in the range of 40 to 50 percent. Practically, that means a meaningful fraction of the year’s rain arrives in a small number of storms, at rates that have nothing to do with the annual average.
A gutter system is a fixed-capacity pipe. Below its capacity it works perfectly and you never think about it. Above its capacity it does not degrade gracefully - it simply overflows, and it overflows along the entire run at once. That is why people describe gutters as having been "fine for fifteen years" right up until the storm that made a mess of the fascia and put water into a wall.
What overflow actually does
- It concentrates water at the eave. The whole point of the gutter was to stop a sheet of water from running off one line. When it overflows, that sheet comes back - only now it is falling from the gutter lip, closer to the wall, straight down onto the same strip of soil every time.
- It soaks the fascia and the eave. Water sheeting over the back or the front lip runs down the fascia board and wicks into the end grain of the rafter tails. This is the damage that costs real money.
- It loads the gutter past what the hangers were sized for.A gutter running full and then blocked is carrying enormous weight. It sags, the pitch is lost, and it never self-drains again.
- It puts water against the foundation. Bakersfield and much of the LA basin sit on expansive clay soils. Repeatedly saturating the same six inches of soil against a footing is a foundation and hardscape problem, not a roofing one - but the roof drainage is what caused it.
- It finds the wall. Splashback and blown overflow at a wall-to-roof junction is a genuinely common source of stucco staining, efflorescence, and interior damage on the top of an interior wall with no plumbing anywhere near it.
The tell: if your gutters overflow along most of the run during the hardest hour of a storm and then drain perfectly afterward, they are not clogged. They are too small - or there are not enough downspouts - and cleaning them again next year will not change it.
Fascia: the board your entire gutter system hangs on
Gutters are almost always fastened to the fascia - the vertical board closing off the ends of the rafters at the eave. Which means the gutter system is only as good as that board, and the gutter system is also the single most common reason that board goes bad. It is a loop, and it runs in one direction.
How the loop works
- Water gets behind the gutter. Usually a missing drip edge or gutter apron, a leaking rear seam or outlet, a gutter hung too low relative to the roof plane, or a run that overflows in heavy rain.
- The fascia stays wet. It is painted wood in most of the housing stock we work on, and it is shaded by the roof edge, so it dries slowly. Paint fails from behind. Once the film is broken, the board takes on water freely.
- Rot moves inward. Into the fascia, then into the end grain of the rafter tails behind it, then into the eave sheathing and the soffit. End grain absorbs water far faster than face grain, which is why the rafter tails are so often worse than the board hiding them.
- The fasteners lose their grip. Hangers and spikes pull out of softening wood. The gutter tilts or sags.
- Pitch is lost and it overflows more. Which wets the fascia more. Which accelerates everything above.
By the time a homeowner notices a gutter "coming loose," the board behind it is usually the actual problem, and re-screwing the hanger is a repair with a very short life.
Signs the fascia is going
- Peeling or blistering paint on the fascia, worst directly under a gutter joint or outlet.
- Dark vertical staining running down the fascia below the gutter line.
- A gutter that has tilted, pulled away at one end, or developed a visible dip mid-run.
- Spike heads backing out and standing proud of the gutter face.
- Soft or spongy wood when pressed, or a screwdriver that sinks in without effort.
- Sagging or stained soffit, or gaps at the soffit-to-fascia joint.
- Any evidence of birds, wasps, or rodents getting into the eave - they get in where the wood has already failed.
What we do about it
Rotted fascia gets replaced before new gutter goes on it, not after. Where the damage has reached the rafter tails, the tails get repaired or sistered - that is carpentry, we price it as such, and we will not screw a fresh board over a bad one to make the estimate look better. On the roof side, the fix is edge metal done right: a drip edge or gutter apron that carries water off the roof edge and delivers it over the back lip of the gutter, so the fascia never sees it again.
This is also why the right time to deal with gutters is with the roof. During areroof the edge is open, the edge metal is being replaced anyway, and the fascia is accessible. Doing it as a separate job later costs more and does less.
Material options, honestly
| Material | What it is | Where it makes sense |
|---|---|---|
| Seamless aluminum | Roll-formed on site to the exact length of the run. Will not rust, takes a baked finish, light enough to hang without heavy structure. | The right default for almost every house we work on, in both of our markets. Gauge matters - thicker stock dents less and holds its shape under load. |
| Galvanized or galvalume steel | Stronger and far more dent-resistant than aluminum. Heavier, and it can corrode once the coating is compromised at cut edges and fasteners. | Where impact resistance genuinely matters - under heavy tree cover, or on runs that take ladder and equipment abuse. Not the choice near salt air. |
| Copper | Very long service life, soldered joints rather than sealed ones, and it patinas rather than corroding. The most expensive option by a wide margin. | Period and estate homes where half-round copper is architecturally correct and the budget supports it. Also a theft consideration worth thinking about. |
| Vinyl | Sectional plastic gutter with snap joints. | We do not recommend it on a house we are also roofing. In high-UV Central Valley and inland LA sun it embrittles, the joints are the weak point, and every joint sits above the fascia. |
Where the water goes after the downspout
Half of the gutter jobs we look at end at the bottom of the downspout, with the elbow discharging directly onto the soil against the house. The gutter did its job and then handed the problem back at the foundation.
- Extensions and splash blocks get the discharge clear of the foundation. Cheap, and they matter more on expansive clay soil than most homeowners realize.
- Underground drain lines to a daylight outlet or an approved discharge point are the better answer where grade allows and where the landscaping justifies it.
- Discharge onto hardscape should be aimed at where the hardscape actually drains, not at the low corner of a patio that then pools against a door threshold.
- Downspout placement is worth thinking about before it is installed - not over a walkway, not at a doorway, not where it drains onto a neighbor.
Grading, drainage beyond the structure, and hardscape work are outside what we do. Where the real fix is a grading problem, we will say so rather than selling you gutters that cannot solve it.
Gutter questions we get asked
Do I even need gutters in Southern California?
Annual rainfall here is low - Kern County gets roughly seven inches a year and coastal Los Angeles County is in the low teens. But almost all of it arrives between November and March, and much of it arrives in a handful of very intense storms. Gutters are not really about total rainfall. They are about keeping concentrated sheets of water off the fascia, out of the wall assembly, away from doorways and walkways, and off the soil right against the foundation. On a house with wide eaves and good grading you can sometimes get away without them. On a two-story wall, over an entry, above a patio, or anywhere the ground slopes toward the house, you cannot.
Five inch or six inch?
It depends on the drainage area, not on the size of the house. Five-inch K-style with 2x3 downspouts is the residential default and it is fine on a modest roof with several downspouts. Six-inch gutter with 3x4 downspouts holds substantially more water per foot and moves far more of it per downspout, and it is the right call on long runs, on large or steep roof planes feeding a single gutter, on valleys that dump concentrated flow into one spot, and on tile. If a roof plane is big and there is nowhere sensible to add a second downspout, the gutter has to get bigger.
My gutters only overflow in heavy rain. Are they clogged or undersized?
Both are possible and the pattern tells you which. If they overflow along most of the run in a hard rain but drain fine afterward, that is usually a capacity problem - undersized gutter, too few downspouts, or downspouts too small. If they overflow in one spot, or hold standing water between storms, or overflow in light rain, that is usually a blockage or a pitch problem. Water spilling over the back edge, against the fascia, is its own category - that is normally a missing or wrong drip edge, or a gutter hung too low relative to the roof plane.
Water runs down behind the gutter and the fascia is stained. Why?
Water leaving the roof edge has to be delivered into the gutter, not merely near it. Without drip edge or a gutter apron carrying the flow over the back lip, surface tension pulls water back under the roof edge and down the fascia board. It looks like a small problem for years and then the fascia is soft, the hangers lose their grip, and the gutter starts pulling away - which makes the overflow worse. This is one of the most common things we correct.
Seamless or sectional?
Seamless, in almost every case. Seamless aluminum gutter is roll-formed on site to the exact length of the run, so the only joints are at corners, end caps, and outlets - the places that get sealed and detailed deliberately. Sectional gutter from a box store adds a joint every ten feet, and every one of those joints is a future leak directly over the fascia. The exception is a short run or a small repair where matching an existing profile matters more.
Can you reuse my existing gutters during a reroof?
Sometimes, and we will tell you honestly which case you are in. Gutters have to come off or be worked around for edge metal and the roof edge detail. If they are aluminum, sound, and correctly sized, taking them down and rehanging them is reasonable. If they are old, dented, undersized, or hung on fascia that needs work anyway, replacing them while the roof edge is already open is far cheaper than doing it as a separate job later. Doing the roof and the gutters at the same time is the correct sequence, and it is also the cheapest one.
Are gutter guards worth it?
Under heavy tree cover, a good guard genuinely reduces cleaning frequency and is worth considering. But no guard eliminates maintenance - fine debris, shingle grit, jacaranda and pepper tree litter, and pine needles all get through or build up on top. Some guard designs also reduce the gutter opening enough to shed water past it in high-intensity rain, which trades a clogging problem for an overflow problem. We would rather size the gutter correctly first and treat guards as a maintenance convenience, not a fix for an undersized system.
How often should gutters be cleaned in this climate?
At minimum once in September or October, before the wet season starts. Under significant tree cover, add a second cleaning mid-winter. In a long dry summer, gutters fill with leaf litter, roof grit, and blown debris that nothing washes out, so they enter the first storm of the season already loaded. That first storm is often one of the year’s hardest.
Do you replace fascia and rafter tails?
Yes. Rotted fascia has to be replaced before new gutter goes up - hanging new gutter on soft wood is throwing away the hangers and the labor. Where rot has reached the rafter tails behind the fascia, that is carpentry, and we will say so and price it rather than screwing a new board over a bad one.
Related services
- Reroofing and roof replacement - the right time to do gutters
- Roof maintenance and wet-season prep - including gutter clearing before the rain
- Roof inspections - gutters, fascia, and drainage are part of the report
- Roof repair - if overflow has already put water inside
- All residential roofing services
What we install
We install seamless gutter systems on residential properties. Seamless means the run is roll-formed to length on site rather than assembled from sectional pieces, so there are no joints along the run to work loose and start weeping — and joints are where sectional gutters almost always fail first.
Gutters are not a side service here. They are the part of the roof that decides whether water leaves the building or sits against the fascia, and an inspection turns up a gutter problem more often than not.
Why call Green Coast for gutters
- Two CSLB classifications - C-39 (Roofing) and B (General Building), in business since 2019 - so fascia carpentry stays in-house.
- We price match like-for-like bids from another licensed contractor.
- California license #1052777 - licensed, bonded, and insured. Verify it at cslb.ca.gov.
What you end up with
A seamless run sized to the actual drainage area, sound fascia underneath it, and water landing inside the gutter instead of behind it - backed by 5–10 years on labor and workmanship.
Where we work
Gutter installation across Los Angeles County and Kern County. See the full list of cities we serve.
Get gutters sized properly
Tell us what the roof does in a hard rain - where it overflows, where the fascia is stained, where the water ends up. That is most of the diagnosis before we get on a ladder.
CA License #1052777. Licensed, bonded, and insured.5–10 years on labor and workmanship.