The materials are capable of long lives: uPVC 25–30 years, aluminium 30+, cast iron half a century and more with paint. Yet we replace gutters far younger than that all the time — because guttering rarely dies of old age. It dies of neglect, sun and bad fixing.
What actually kills gutters
Blockage is the great killer: a gutter full of leaves and moss holds standing water and silt, whose weight strains joints and brackets year-round and whose overflow damages the wall below — the damage transfers to your house even while the gutter itself survives. UV embrittles uPVC over the decades; faded, chalky plastic cracks at joints that supple new material would shrug off. Fixing failures — brackets pulling out of rotten fascia boards — take healthy gutters down with them, which is why gutter problems and fascia problems so often arrive together. And rusted backs quietly end cast iron where nobody ever looks.
The signs yours is failing
Drips from joints you can hear at night; green algae stripes on the wall below the gutter line; sagging sections that hold water after rain has stopped; plants growing in the run. Indoors: damp at the top corners of rooms on outside walls — the classic overflow signature (see damp after heavy rain).
Repair or replace?
One weeping joint on sound, supple guttering: a new union, minutes of work. A run that's lost its fall: re-bracketing. But multiple failures on brittle, faded plastic mean each repair stresses the next weak point — replacement is the honest call, and it's a modest job that usually pairs naturally with fascia work while access is up. The full picture is on our guttering page — and whatever you do, clear them annually; it's the cheapest roof maintenance that exists (see roof care).