How Often Should Gutters Be Cleaned? (And What Your Overflowing Gutter Is Telling You)
Most London houses need their gutters cleaned once a year, in autumn once the leaves are down. Make it twice a year if trees sit close to the house or the roof is shallow enough to hold moss, and more often for flats and blocks with box gutters or internal outlets.
That's the short answer. The rest is for the homeowner or landlord watching rain pour over the front of the gutter this autumn, or staring at a damp patch on a bedroom wall and wondering if the two are connected. Often, they are.
How often should gutters be cleaned, really?
Once a year is the right baseline for most London properties. Timing matters as much as the number, though. Clear a gutter in early September, with half the leaves still on the trees, and it can be full again by Bonfire Night.
Historic England's maintenance checklist for older homes says the same: clear debris and blockages "after heavy leaf fall, at least every autumn and preferably more often".
How we'd split it:
- Once a year, in late autumn, for a typical house with no big trees nearby.
- Twice a year, autumn and spring, if trees are close enough to drop leaves or seeds into the gutter, or the roof is a shallow pitch that holds moss.
- More often for flats and blocks with box gutters or internal outlets. A blocked box gutter can't spill over a front edge, so the water backs up and some of it can find its way inside.
That's the same guidance we give for our gutter and downpipe clearing.
Moss on the roof feeds the gutter
A green roof means a gutter that keeps filling. Rain and birds knock clumps of moss loose, they slide down into the gutter, and there they hold grit like a sponge right over the outlet.
Clearing the gutter sorts this year. Getting the moss off the roof itself is what slows the refill.
When to clean gutters in London (and why October catches people out)
October and November are when gutters let people down. The leaves come off, the storms start, and a gutter that coped all summer suddenly can't.
The Met Office marked 1 September as the start of the 2026/27 storm-naming season. In the same update it said this summer had provisionally become the UK's warmest on record, with many areas getting less than half their average seasonal rainfall.
That's bad news for gutters. Months of blossom, seeds and grit build up with no heavy rain to flush them through, then the first proper downpour shoves the lot towards the outlet at once.
So when should you book?
- Already overflowing? Don't wait for the last leaf. Clear it now, and look again in late winter if a big tree hangs over the house.
- Not overflowing yet? Late autumn, once the nearest trees are mostly bare, gets the most out of a single visit.
Signs of a blocked gutter you can spot from the ground
None of these need a ladder:
- Water running over the front edge in heavy rain
- A stripe of green or black staining down the wall below a joint
- Plants growing out of the gutter, which means there's enough silt in there to root in
- A downpipe that stays silent while it's pouring
- Damp on an upstairs internal wall
People rarely connect that last one to the gutter. If a damp patch appears high on an inside wall, check the outside of that wall before you call a roofer. A blocked outlet or a leaking joint right behind it is the cheap cause, and it's worth ruling out first.
What overflowing gutters are telling you
Not every overflow is a blockage. Where the water comes over tells you most of what's going on.
All along the run, or near the downpipe. The outlet or the downpipe is usually blocked, so water backs up until it spills.
At one spot in the middle. Either debris is damming it, or the gutter has dropped at a bracket and made a low point. Historic England's checklist asks the same question: "Does the water pool in any one area?"
From a joint. That's a failed seal, not dirt. Cleaning won't fix it.
Only in a cloudburst, with the gutter clear and the downpipe roaring. The gutter may be too small for the roof feeding it. That's one for a roofer or gutter fitter.
Up out of the drain at ground level. The blockage is underground. That's a drainage job.
How to check yours in a downpour
The same checklist says to inspect "while it is raining and note any leakages". You can do all of it from the ground:
- Wait for proper rain, not drizzle.
- Walk round every side of the house, side return included, and look along the front edge of each gutter.
- Stand by each downpipe and listen. A silent downpipe in a downpour is blocked somewhere above you.
- Check the gully at the bottom of each pipe is coping.
- Watch the joints and corners for drips.
- Film anything odd. Thirty seconds of video tells a gutter cleaner more than any description.
- Next dry day, look under each joint and outlet for dark wet patches or green streaks.
What happens if you leave a blocked gutter
Not much, for a while. That's the trouble with it.
Water that should go down the pipe runs down the wall instead, in the same place every time it rains. That patch never properly dries, and the green or black stripe follows. On render it can be stubborn, and our guide to cleaning render without damaging it covers what works. Fix the gutter first, though, or the stripe comes straight back.
Then it can come inside. The government's guidance on the health risks of damp and mould describes penetrating damp as "water that gets into the building from outside due to defects in the walls, roofs, windows or floors". Its list of external checks for finding the cause of damp starts with "damaged or blocked pipes, gutters or downpipes".
The same guidance says damp and mould "primarily affect the airways and lungs, but they can also affect the eyes and skin". A few leaves are no reason to panic, but a damp patch that arrived with the autumn rain deserves a proper look.
Outside, timber fascia boards behind an overflow stay wet and start to rot, and a gutter packed with wet silt keeps its brackets under strain all winter.
Landlords: gutters are part of your repairing duty
Section 11 of the Landlord and Tenant Act 1985 implies a covenant by the landlord "to keep in repair the structure and exterior of the dwelling-house (including drains, gutters and external pipes)". Section 13 applies it to leases granted on or after 24 October 1961 for a term of less than seven years.
The Act is about repair, not a cleaning schedule. But a blocked gutter is how a small job turns into a damp bedroom wall or a rotten fascia, and that repair is yours either way.
Book the gutters in autumn, ideally at a changeover, and keep the before and after photos with the property records. You can't see inside a gutter from the ground, so the photos are your proof it was done.
If you look after several properties, see how we work with landlords and letting agents. In a block of flats, check who the lease makes responsible for the structure before booking anything.
What a proper gutter clear includes (and what changes the price)
A gutter clean that stops where the ladder stops isn't a gutter clean. A full gutter clearance should include:
- The full run, not just the sections that are easy to reach
- Downpipes checked and flushed through to the drain. A spotless gutter feeding a blocked downpipe still overflows.
- Moss, leaf litter, grit and nesting material removed and taken away, with borders and paths left tidy
- Before and after photos of the inside of the gutter
- Fascias and soffits washed down, if you'd like them done
Where the roofline is safe to reach, we work from the ground, so nobody leans a ladder on your guttering. And we clean gutters, we don't fit them. If we find a cracked joint or a dropped length, you get a photo and an honest word about it, not a sales pitch.
Having more of the outside done? The sensible order is gutters and fascias first, then walls, then glass, so nothing from the gutter lands on a clean window.
What changes the gutter cleaning cost
We don't publish prices, because two houses on the same street can be very different jobs. What moves a quote:
- Length of the run, and how many storeys up it sits
- Access, such as narrow side returns, parked cars, or a garden you can only reach through the house
- A conservatory or extension roof underneath, which means slower, more careful work
- How bad it is, from a light layer of leaves to compacted silt with plants rooted in it
- How many downpipes there are, and whether any are blocked
The quote is free and fixed before any work starts.
When it isn't worth paying (and how to do it yourself safely)
Sometimes you don't need us, and we'd rather tell you than take the money.
If your gutters are single-storey, say a bungalow or a low extension you can reach from a sturdy step on firm, level ground, and leaf fall is light, do it yourself with gloves, a small trowel and a bucket. Then pour a bucket of water in at the far end and watch it run to the outlet, which is the slope test Historic England suggests.
If the downpour check above showed every gutter running clear and every downpipe roaring, skip it this year. And if the gutter is cracked or sagging, a clean won't help. You need someone who fits gutters.
What we'd ask you not to do is clear a two-storey gutter from a ladder, least of all in the rain. HSE's guidance on leaning ladders is written for work, but gravity doesn't change at home. It says not to rest a ladder "against weak upper surfaces such as glazing or plastic gutters", and to "maintain three points of contact when climbing and wherever possible at the work position".
Gutter clearing means one hand in the gutter and the other on a bucket while you stretch along the run. You can see the problem.
FAQ
How often should gutters be professionally cleaned? Once a year for most London houses, in late autumn once the leaves are down. Twice a year if trees are close or the roof holds moss, and more often for box gutters or internal outlets.
How much should you expect to pay for gutter cleaning? It depends on the length of the run, the number of storeys, access, how blocked it is and how many downpipes there are. Our quote is free and fixed before any work starts.
Does gutter cleaning include downspouts? It should. In the UK we call them downpipes, and a clean gutter draining into a blocked one still overflows. Ours includes flushing every downpipe through to the drain.
What happens if I don't clean the gutters? Rainwater runs down the wall instead of the pipe, staining brick and render and keeping them wet. The government's damp and mould guidance lists blocked gutters and downpipes among the external checks for the cause of damp, so it can end up inside too.
Is it too late to clean gutters in winter? No. A gutter cleared in December still does its job through January and February. If a big tree overhangs the house, plan a second clear in spring.
Do you repair or replace gutters? No, we clean them, we don't fit them. If we find a cracked joint or a dropped length, we photograph it and tell you straight.
Get your gutters cleared before the worst of the winter
If water's coming over the front of your gutter, or there's a damp patch upstairs you can't explain, film it next time it rains and send it to us. We'll tell you honestly whether it looks like a blockage we can clear or a fault that needs a fitter. You can see what's included in our gutter clearing service first.
Get a free, no-obligation gutter clearing quote, call us on 07375 104665, or message us on WhatsApp at wa.me/447375104665 for a same-day answer. We cover North London and the Hertfordshire borders.
Last updated: 23 September 2026
About Techno Clean: a London deep-cleaning company covering North London and the Hertfordshire borders. We specialise in one-off deep cleans, end of tenancy and after builders cleaning, fully insured with £5 million public liability cover and DBS-checked teams, rated 4.9 from over 180 reviews across 500+ completed jobs.
