Water cascading over the gutter edge like a waterfall every time it rains, a damp patch creeping up the wall, plants cheerfully growing in the gutter itself — leaking gutters are one of those problems that announce themselves loudly and get worse fast. Left alone, overflowing gutters soak walls, damage foundations and rot fascias. The good news: most gutter leaks are DIY-fixable in an afternoon. Here’s how to fix a leaking gutter yourself.
How to fix a leaking gutter myself
Safety first (non-negotiable)
You’re working at height. Use a stable ladder on firm, level ground, ideally with someone footing it. Don’t lean sideways off the ladder — move it instead. Don’t work in high winds or on icy surfaces. If your gutters are above a conservatory or extension roof you can’t safely reach, this becomes a professional job — no leak is worth a fall. For anything beyond single-storey height that feels sketchy, get a quote; gutter repairs are cheap professionally (£80–£150).
Step 1: Clean the gutters
Half of all “leaks” are actually blockages — water overflows because it can’t reach the downpipe. Before anything else:
- Scoop out leaves, moss and silt with a trowel or gutter scoop (gloves on — it’s grim).
- Flush through with a hose to check flow to the downpipe.
- Check downpipes for blockages — disconnect at the shoe and rod through if needed.
Do this twice a year (late autumn after leaf fall, and spring) and you’ll prevent most gutter problems entirely. Gutter guards (£2–£5/m) reduce the leaf load if you’re surrounded by trees.
Step 2: Find the actual leak
With gutters clean, run water through with the hose and watch. Common leak points:
- Joints between sections: the most common — rubber seals perish after 10–15 years.
- Cracks or splits: usually from frost, ladders leaning on the gutter, or age.
- Sagging sections: brackets too far apart or pulled loose; water pools instead of flowing.
- End caps and corners: seals fail here first.
- Downpipe connections: the shoe or swan-neck joints work loose.
Step 3: Fix by leak type
- Leaking joints: unclip the joint, clean both ends, replace the rubber seal (£2–£5 for a seal kit) or apply gutter sealant to the joint and re-clip. If the gutter has dropped, reposition with the correct fall (about 1:600 — barely visible, but water must flow).
- Small cracks/holes: clean and dry the area, then apply gutter repair sealant or a self-adhesive flashing tape patch. For uPVC, solvent-weld repair works on clean breaks.
- Sagging: add extra gutter brackets (£1–£2 each) — they should be max 1m apart, 150mm from joints. Re-establish the fall toward the downpipe.
- Perished seals throughout: if every joint weeps, the system’s at end of life. Replacing a full gutter run is still DIY-able (£100–£250 in materials for an average house) — or get a professional quote.
- Leaking downpipe joints: reseal with gutter sealant or replace the affected section — downpipe clips and sections are cheap and standardised.
When to replace instead of repair
Repair makes sense for isolated issues on gutters under 15 years old. Replace when: multiple sections are brittle or cracked (uPVC degrades in UV), the system sags in several places, repairs keep failing, or you’re already scaffolding for roof work (doing gutters while access is up saves hundreds). Full replacement professionally costs £600–£1,200 for a typical 3-bed semi.
Prevention
- Clean twice yearly — the single most effective maintenance.
- Trim overhanging branches — fewer leaves, less moss, less weight.
- Check after storms — high winds shift sections and loosen brackets.
- Don’t lean ladders directly on gutters — use a stand-off or ladder stay.
- Paint/treat fascias when you do the gutters — rot behind the gutter is the hidden companion problem. Our exterior paint guide covers weatherproof coatings.
Small exterior fixes like this pair well with other DIY plumbing confidence-builders — fixing a dripping tap uses the same “diagnose, disassemble, replace the seal” logic indoors.
Gutter guards: worth it?
Gutter guards — mesh or brush inserts that sit in the gutter and keep leaves out — are a £2–£5-per-metre question with a nuanced answer. Brush guards (the “hedgehog” type) are cheap and easy to fit, but they trap silt and seeds, need pulling out and cleaning every year or two, and can actually make blockages worse if neglected. Mesh guards work better — water flows through, leaves blow off — but they’re fiddlier to fit and cost more. The honest verdict: guards help if your gutters fill with leaves (near trees), but they’re pointless against moss and silt (the main culprits in most urban gutters), and they’re no substitute for the twice-yearly clean. If you fit them, commit to lifting and checking them annually — a guarded gutter you never inspect is a blocked gutter you can’t see.
Downpipes, gullies and soakaways
The gutter is only half the system — water has to go somewhere. Common downstream problems:
- Blocked gully: the drain at the bottom of the downpipe fills with silt and leaves. Lift the grate (a screwdriver usually does it) and scoop it out — a 5-minute job that prevents water backing up the downpipe.
- Downpipe discharging onto the ground: it should connect to a drain or soakaway, not pour onto the soil next to your foundations. Persistent damp at the base of a wall often traces to exactly this.
- Soakaway failure: if the ground around the soakaway is permanently boggy, the soakaway is silted up or undersized. Digging a new one (1m³ pit filled with rubble, wrapped in membrane) is a weekend job at £100–£200 in materials — or a £500–£1,000 professional job.
- Rainwater harvesting: while you’re at it, a water butt on the downpipe (£30–£60) gives free garden water and reduces the load on the drains. The plants prefer rainwater anyway.
If any of this involves working beyond safe ladder reach, get a professional — guttering specialists are among the cheaper trades to hire, and Which?’s trader advice helps you find one worth using.
The takeaway
Clean first (it’s usually a blockage), find the leak with a hose, then fix by type: new seals for joints, sealant for cracks, extra brackets for sags. An afternoon’s work, under £30 in materials, and your walls stay dry. Work safely at height — and call a professional the moment it feels unsafe.
