Gutter repair
Most gutter problems are three problems wearing a trench coat
Sagging, leaking and overflowing look like one problem from the ground and are three different repairs. Which one it is determines whether this is an afternoon or a replacement.
Start by working out which one it is
| What you see | What it usually means | The repair |
|---|---|---|
| Water sheets over the front in every rain, in one spot | A blockage, or a dip holding debris at that point | Clear it, then check the pitch and hangers where it dipped |
| Water goes over only in heavy rain, along a long stretch | Capacity: the trough or the outlet is undersized for the roof feeding it | A larger outlet, an extra downspout, or a larger trough on that run |
| Dripping at a corner or an end | A failed seam or end cap seal | Clean and re-seal properly, or re-make the joint; sealant over old sealant does not bond |
| The run has pulled away from the fascia at the top edge | Fasteners have lost their grip, usually in soft wood | Re-hang into sound wood with hidden hangers; replace fascia where it is gone |
| Water runs behind the gutter and down the fascia | No drip edge or gutter apron at the eave | Fit an apron; this is the repair that stops the fascia rotting again |
| Standing water in the trough when it is dry out | Pitch is flat or reversed, or the run has sagged | Re-pitch to the outlet; check the hangers that let it move |
Before the diagnosis table, the whole problem in a little over a minute: the four things that actually make a gutter spill, and how to tell which one you are looking at.
Read the transcript
Most gutter overflows have nothing to do with holes. They come down to four things: the edge, the slope, the size, and where the water ends up. Start at the roof edge. The drip edge should lap into the back of the gutter. If it stops short, water runs behind the gutter and rots the fascia board. Hidden hangers hold the gutter to the fascia. When they work loose, the gutter starts to sag. And a sag is where water pools, then spills over the front. A gutter also needs a steady fall toward the downspout. About ¼ inch for every 10 feet. Size matters too. A 6-inch gutter carries about 40% more water than a 5-inch. And a 3×4 downspout has twice the opening of a 2×3. Finally, the downspout. If it dumps water right at the house, you've just moved the problem to your foundation. An extension should carry it 4 to 6 feet away. If your gutters overflow in a hard rain, a free inspection will tell you which of the four it is.
The drawing below follows the water through the version of this that is about slope and discharge rather than holes: the sag, the overflow, and where the downspout ought to finish.
What a repair can and cannot bring back
Aluminum that has been bent, unbent and re-fastened several times work-hardens and creases, and the front lip never returns to a straight line. A gutter with elongated fastener holes along its back edge has run out of places to grip. Neither is a reason to replace a whole house of gutter, but both are reasons to stop repairing one run.
- Sealant does not fix a moving joint. If the corner leaks again a season after it was sealed, the corner is moving and it needs to be re-made rather than re-sealed.
- A gutter that has held ice repeatedly is usually distorted along the front, and it will hold water at those points for the rest of its life.
- Spikes and ferrules that keep working loose cannot be fixed by driving them back in. The hole is bigger than the spike now.
- A run that was never pitched cannot be made to drain by cleaning it.
The question worth asking on any gutter repair is why it failed, not just what failed. Almost every recurring gutter problem in this market traces back to water getting behind the trough, which is a missing edge detail on the roof rather than a defect in the gutter.
When repair stops being the answer
- The fascia is soft along most of a run, so there is nothing to hang anything on.
- The same run has been re-hung two or three times and keeps moving.
- The gutter is visibly undersized for the roof, in which case a perfect repair reproduces the overflow.
- The profile is obsolete and the corners and outlets cannot be matched, which makes each repair a fabrication job.
Not sure whether you need a repair, a re-hang or a replacement?
Request a free inspectionCan a sagging gutter just be re-hung?
If the fascia behind it is sound, yes — hidden hangers into solid wood at a tighter spacing usually solve it permanently. If the wood is soft, the hangers have nothing to hold, and the fascia comes first.
Why does the same corner keep leaking?
Because the joint is moving with temperature and the sealant is being asked to be a structural element. Aluminum expands and contracts measurably along a long run, and a rigid sealed corner takes all of that movement.
Is it worth repairing gutters on a roof that needs replacing soon?
Usually the sensible order is to sort out the leak that is doing damage now, and then do the gutters properly when the roof is done, because that is when the drip edge and apron detail can be built correctly. Anything urgent enough to be rotting wood should not wait.
Do you work on gutters if you did not install them?
Yes. Most gutter repair is on somebody else's work, and the useful part is finding out why it failed rather than who installed it.
All work is performed by licensed and insured local roofing professionals.