Domakihub How to Fix a Leaking Gutter Before It Damages Your Home
Stop water damage at the source with this straightforward gutter repair guide.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
A dripping gutter might look minor, but in Greece's climate — where heavy autumn downpours follow long dry summers — even a small leak can send water straight into render, window frames, or foundations. The This Old House video above shows the repair in real time; this article walks you through the exact steps so you can tackle it yourself on any property, from a Crete villa to an Athens apartment block. Most fixes take under an hour and cost less than €15 in materials.
Why Gutters Leak (and Why It Matters in Greece)
Gutters most commonly leak at joints, end caps, and outlet holes — places where sealant ages and cracks, or where small debris dams hold standing water that corrodes the metal or plastic housing. In Greece, UV intensity degrades sealant faster than in northern Europe, and the combination of roof dust, pine needles, and olive leaves blocks outlets quickly. A blocked or leaking gutter channels water directly down the exterior wall, eventually causing efflorescence, mould, and structural damp that costs far more to fix than the gutter itself.
Holiday rentals and hotels face an additional risk: a water stain above a guest-room window or a dripping soffit by the entrance creates an immediate negative impression — and potentially a negative review. Catching the leak early and repairing it properly protects both the asset and the guest experience.
Tools and Materials You Will Need
You need very little: a sturdy ladder, rubber gloves, a stiff brush or old paintbrush, a cloth, gutter sealant (silicone or butyl-based — both are sold at any Greek builders' merchant), and replacement gutter screws or pop rivets if a bracket has pulled away. If the leak is at a union joint, also buy a replacement rubber gasket that matches your gutter profile (half-round or ogee/K-profile are the two common types in Greece). A tube of grey gutter sealant costs roughly €6–10; a pack of gaskets €3–5.
Optional but useful: a garden hose to test the repair before coming down the ladder, and a small mirror or phone camera to inspect the inside of the channel from a safe position.
5 Steps to Fix a Leaking Gutter
- 1
Locate the exact source of the leak
On a dry day, run a hose into the gutter at the highest point and watch where water escapes. Leaks most often appear at union joints between sections, at the end cap, or around the outlet (the drop that connects to the downpipe). Mark each leak with a strip of tape so you do not lose track once the hose is off.
- 2
Clear the gutter and let it dry completely
Scoop out leaves, grit, and any standing water, then scrub the inside surface of the gutter at and around each marked spot with a stiff brush. The repair sealant will not bond to wet, dirty plastic or aluminium — give the area at least 30 minutes to dry in the sun, or wipe it firmly with an absorbent cloth followed by a dry rag.
- 3
Re-seal joints and end caps
Cut the nozzle of the sealant tube at a 45-degree angle to a 5 mm opening, load it into a caulking gun, and run a continuous bead along the inside of the joint or end cap seam. Press the sealant firmly into the gap with a wet gloved finger, smoothing it into a concave profile so water flows over rather than behind it. For a union joint with a failed rubber gasket, pull the two gutter sections apart, replace the gasket, push the sections back together until they click, then run a thin bead of sealant over the join on the inside as insurance.
- 4
Fix loose or missing brackets and realign the fall
A sagging gutter holds water rather than draining it, and the standing water accelerates corrosion and joint failure. Push any loose brackets back into the fascia board and drive a new stainless-steel screw through the original hole. Use a string line or a long spirit level to check the fall: gutters should drop at least 5 mm for every 1 metre of run toward the outlet. If the whole run has dropped, loosen all brackets, reposition, and re-screw.
- 5
Test, wait 24 hours, and test again
Run the hose from the high end once more and watch every repair point carefully. Butyl sealant skins over in roughly one hour but cures fully in 24 hours; silicone cures similarly. Do not allow rain or a second hose test within the first hour. After full cure, do a final hose test, then visually inspect from ground level after the next real rainfall to confirm everything is dry and running freely to the downpipe.
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FAQ
- Can I repair a gutter while it is still wet after rain?
- No. Sealant will not bond to a wet surface and the repair will fail within weeks. Wait for a dry spell of at least half a day and wipe the area clean before applying any product. If you need a very fast temporary fix during a rainy period, self-adhesive aluminium repair tape can bridge a crack and hold until conditions allow a proper sealant repair.
- How do I know whether to repair or replace the gutter?
- If the gutter has isolated leaks at joints or end caps but the channel itself is intact, repair is the right call. Replace the section if you see cracks running along the channel floor, the plastic has become brittle and crumbles when handled, or the same joint has been repaired more than twice in five years. Aluminium gutters in Greece typically last 20–30 years; PVC around 15–20 years depending on sun exposure.
- What type of sealant should I use for gutters in Greece?
- Butyl or modified-bitumen gutter sealant (sold as 'mastika alouminiokalyvon' or gutter mastic at builders' merchants) is the most widely available and forgiving option. UV-stable silicone also works well and is slightly easier to smooth. Avoid standard white bathroom silicone — it degrades quickly in standing water and the sun's UV rays. Whatever you choose, make sure the label states it is suitable for plastic or metal gutters and is waterproof.