A gutter that overflows is not always a blocked gutter. Four different faults produce the same waterfall, and only one of them is cured by scooping out leaves. Before anyone charges you for a clean, it is worth working out which of the four you have, because a gutter with the wrong fall will overflow again a fortnight after it is cleared. The quick version: if it overflows in every shower it is usually a fall or joint problem, if it only overflows in downpours it is usually a blockage, a sizing issue or water arriving faster than the outlet can take it.
Watch where the water leaves, not where it lands
Stand back during a downpour with an umbrella and look at the gutter line rather than the puddle. Water spilling evenly along a long run points to a fall problem or a run that is simply full. Water spilling from one fixed point every time points to a local blockage, a dropped bracket or a failed joint at that spot.
Water appearing to come from behind the gutter, running down the fascia board rather than over the front lip, is a different fault altogether and a more damaging one, because that water is landing inside the wall head rather than on the path.
- Even spill along a run: fall is wrong or the section is undersized
- One point spilling: blockage, sagging bracket or split joint
- Water behind the gutter: eaves detail rather than the gutter itself
- Water only at a corner: outlet or downpipe restriction below
The blockage version
Norfolk gutters fill with a predictable mixture: moss washed off north-facing tiles, silt from mineral felt or from a tired concrete tile surface, lime and leaf litter from overhanging trees, and every so often a nest. Moss is the big one on older pantile and concrete tile roofs, because it sheds constantly in wet weather and settles at the low end of the run.
A blocked gutter shows itself in a pattern. It holds water after the rain stops, it grows a green tide line along the front lip, plants germinate in it, and the wall or fascia below the blockage stains darker than the rest of the elevation. If the gutter has weeds in it, the blockage is old.
The fall, joint and bracket version
A half round or square line gutter needs a consistent fall towards the outlet. Where a run has been refixed over the years, or where a fascia has softened and let a bracket pull out, the line develops a low spot in the middle and the water simply stands there and tips over at the lowest point. You can see it clearly on a dry day as a dirty tide mark on the inside of the gutter that is not level with the top edge.
Joints are the other steady failure. Union brackets rely on a rubber seal that hardens with age and ultraviolet light, so a twenty year old plastic system leaks at almost every joint even when it is clean. Old cast iron leaks at bolted joints where the putty has gone. Neither is fixed by clearing debris.
The eaves detail version, which matters more than people think
On a correctly built roof, the underlay carries any water that gets past the tiles down into the gutter, usually over a rigid eaves protection tray. On plenty of older roofs the underlay was cut short, or has rotted back at the eaves, so water running down the underlay drips behind the gutter and straight onto the top of the wall and the ends of the rafters.
This is why a gutter problem sometimes turns out to be a rot problem. If the fascia is soft, if the first foot of rafter feels spongy from inside the loft, or if the wall head is permanently damp inside, the water has been getting behind the gutter for a long time and the repair is a roofline repair rather than a gutter clean.
- Underlay finishing above the gutter instead of into it
- No eaves protection tray, so the underlay sags and drips short
- Fascia soft to a screwdriver point, or paint blistering from behind
- Green algae stripe on the wall directly under the eaves
What you can safely do yourself, and what you should not
From the ground, a telescopic gutter cleaning wand or a hose on a curved lance clears a lot of ordinary silt safely, and checking that the bottom of the downpipe is not blocked by leaves or a collapsed gully takes a minute. Watching the roof in the rain from a window is genuinely useful diagnosis and costs nothing.
What we would not encourage is a ladder leant against a plastic gutter. Guttering is not designed to take the weight of a ladder or of someone leaning sideways from one, and gutter falls are one of the most common domestic ladder accidents in the country. A bungalow gutter in dry conditions with someone footing the ladder is one thing. A two storey Victorian eaves gutter over a sloping garden is not.
When it needs a roofer
Bring someone in when the gutter has been cleared and still overflows, when joints leak, when the fascia or soffit is soft, when the run visibly sags, or when water is getting behind the line. Those are all repairs rather than maintenance, and they are the ones that go on to cause damp inside if they are left through a winter.
We handle guttering, fascia and soffit work as part of general roof repairs, and inspections are free with a written no obligation quotation, so you can find out which of the four faults you have before deciding anything.
Common questions
Why does my gutter only overflow in very heavy rain?
Because the run is coping with ordinary rainfall but not with peak flow. That usually means a partial blockage, an outlet that is too small for the roof area draining into it, or a valley discharging a large volume into one short section of gutter.
How often should gutters be cleared in Norfolk?
Once a year suits most houses, usually after leaf fall. Properties with overhanging trees, or older roofs shedding a lot of moss, often need twice a year to stay clear through the winter.
Can an overflowing gutter really cause damp inside?
Yes. Water spilling repeatedly onto the same patch of wall saturates the masonry, and water getting behind the gutter soaks the wall head and rafter feet directly. Both show up indoors as damp at the top of an upstairs wall or in the corner of a ceiling.
Is it worth replacing old plastic guttering rather than repairing joints?
If a handful of joints leak on an otherwise sound run, repair makes sense. If the plastic has gone chalky and brittle and several unions are failing at once, replacing the run costs little more than chasing individual joints and lasts far longer.
Do you replace cast iron guttering like for like?
We can advise on either replacing cast iron in kind on period and listed properties where appearance matters, or fitting a modern equivalent elsewhere. It is one of the things we look at during the free inspection.