How to Fix Leaking Gutter Seams and Corners
Most gutter leaks happen at the joints: inside and outside corners, end caps, and the outlet where the downspout connects. Old sealant dries out, cracks with temperature swings, and water starts dripping onto the walkway or brick.
How a seam is re-sealed properly
- Clean the gutter and let the joint dry completely.
- Scrape out the old, cracked sealant with a putty knife.
- Scrub the metal with a wire brush and wipe it with a solvent so the new sealant bonds.
- Apply a continuous bead of gutter-grade sealant (not regular silicone) inside the joint and press it in.
- For gaps or holes, add an aluminium patch bedded in sealant first.
- Let it cure before the next rain and test with a hose.
When sealing is not enough
If the joint is bent, the gutter is rusted through, or the leak comes back every season, the section usually needs to be replaced. Seamless aluminum gutters have joints only at the corners and outlets, so there are far fewer places to leak.
More guides: How often to clean gutters · Signs of a clogged downspout · Ice dams & winter gutters · Choosing gutter size: 5", 6" or 7"