DOE/PNNL Building America
Size the drainage path
Federal Building America guidance calls for adequately sized gutters and downspouts that direct water away from the foundation.
Read the sourceGround-level inspection guide
What is wrong with my gutters?
Match the visible symptom to likely system problems, collect the right evidence, and decide whether to ask for cleaning, repair, drainage work, or replacement. This guide helps structure the conversation; it does not diagnose concealed damage.
Start with safety
Do not use a ladder or walk on a roof during rain, high wind, ice, or when a gutter section is loose. Keep people away from a hanging run. Active interior water entry, loose components, electrical exposure, or rapid foundation-area flooding needs prompt professional attention.
Symptom-to-scope table
Record what happens before deciding the fix
One symptom can have several causes. The useful question is not only “where is the water?” but “where did control of the drainage path first fail?”
| Visible symptom | Possible causes | What to record safely | Repair-versus-replace signal |
|---|---|---|---|
| Overflow along a long section | Debris, insufficient pitch, undersized gutter, or too few outlets | Observe whether overflow begins at a valley, low spot, or outlet. Check again only from the ground after the rain. | Cleaning or pitch/outlet correction may work; repeated clean-system overflow can require redesign. |
| Water running behind the gutter | Drip-edge or flashing path, gap at roof edge, loose attachment, or fascia deterioration | Look for staining behind the run, wet fascia, peeling finish, or water reaching siding. | Correct the water-entry path and assess fascia before simply resealing the front. |
| Sagging or a visible low spot | Loose or failed hangers, damaged fascia, trapped debris, ice load, or incorrect spacing | Sight along the run from the ground and compare hanger positions. Keep clear if a section appears loose. | Localized fastening may be repairable; distorted runs or unsound fascia need broader work. |
| Leak at a seam or end cap | Failed sealant, movement, corrosion, impact, or loose joint | Photograph the exact leak point and note whether the surrounding material is still rigid and sound. | One sound joint may be resealed; repeated seam failures favor longer replacement runs or seamless gutters. |
| Standing water after rain | Wrong pitch, localized sagging, blocked outlet, or settled attachment | Check after the storm from a safe window or ground view; never climb onto a wet roof or ladder. | Re-pitching may solve a sound run; permanent deformation or fascia failure may not. |
| Downspout backs up or joints spray | Clogged elbow, crushed extension, restricted underground pipe, or inadequate outlet size | Start at the discharge point and note whether water exits freely. Do not assume the gutter itself is the only problem. | Clear or repair the full discharge path; resizing may be needed when clean components cannot carry peak flow. |
| Rust holes, cracks, or widespread pinholes | Material aging, coating failure, freeze-thaw movement, impact, or long-term standing water | Record how many sections are affected and whether damage appears around every seam or fastener. | One isolated defect may be patched; widespread material failure usually favors replacement. |
| Pooling or erosion near the foundation | Short, disconnected, blocked, or poorly directed downspout; grading can also contribute | Trace the outlet and photograph the discharge area after rain. Check local rules before redirecting water. | Extend or redesign discharge to a suitable location and address grade or drainage issues when present. |
Evidence for the quote
A five-minute rain observation
Stay on the ground or observe from a safe window. A short video often explains the failure better than a dry-day description.
- 1Record where overflow first appears: roof valley, middle of a run, end cap, or outlet.
- 2Check whether water is going over the front, behind the gutter, through a seam, or from a downspout joint.
- 3Record whether each downspout is discharging and where the water goes afterward.
- 4Photograph stains, erosion, pooling, loose hangers, peeling fascia, or wet siding after conditions are safe.
- 5Note whether the system was recently cleaned and whether the same problem occurs in light rain or only intense rain.
What public building guidance says
Fairfax County Soil and Water
Read the exterior clues
Exterior streaks, watermarks, and erosion along the drip line can indicate overflow and should trigger inspection.
Read the sourceNC State Extension
Inspect after major weather
NC State recommends regular gutter inspection and another check after major weather events.
Read the sourceGutter damage questions
Why do clean gutters still overflow?
A clean system can overflow if the runs are undersized, the pitch is wrong, outlets or downspouts are too limited, roof valleys concentrate flow, or an underground connection is restricted. Observe where overflow starts and have the complete drainage path checked.
Does standing water mean the gutter needs replacement?
Not automatically. Standing water commonly points to insufficient pitch, loose hangers, localized sagging, or a blocked outlet. Repair may work when the material and fascia are sound; widespread deformation or recurring movement may justify replacement.
Can a leaking gutter damage the foundation?
Gutter and downspout failures can concentrate roof runoff near foundation walls. Federal building guidance recommends directing roof water down and away from the home. Soil grade, drainage, and the discharge point also affect the result.
When is gutter damage urgent?
Treat a detached or falling section, water entering the building, overflow near electrical equipment, severe fascia failure, or concentrated discharge causing active interior or foundation leakage as urgent. Stay off ladders during storms and keep people away from loose components.
Describe the symptom, not your guess
Tell the contractor where water appears, when it happens, and what the discharge point is doing. That evidence supports a more accurate repair or replacement scope.