The phone call almost always comes on day three.
By then the standing water has gone, somebody has run a domestic dehumidifier in the hall for two nights, the carpet feels damp rather than wet, and there’s a smell in the room that the caller describes as musty and I would describe as the beginning of something worse. The question is always the same. Can it be saved.
Sometimes. The honest answer depends on three things, and only one of them is the carpet.
What kind of water was it?
Clean, dirty, or the third kind. That’s the first question I ask and it decides most of what follows.
Water from a burst supply pipe, a split washing machine hose or an overflowing bath is clean at the point it escapes. Water that has come through a ceiling void, run across a floor for six hours, or arrived from a garden after heavy rain is contaminated – not dangerously, but it’s picked up soil, bacteria and whatever was on the surfaces it crossed. Water containing sewage is the third category, and there is no version of that conversation where the carpet stays. It comes up, it goes in a skip, and anyone offering to clean and sanitise it in place is selling you something they can’t deliver.
Ground-floor flats catch all three, and they catch the third one more often than upper floors do, because that’s where the drainage runs and where a backed-up gully finds its way in.
Why the source matters more than the depth
Two centimetres of foul water is a write-off. Ten centimetres of clean tap water in a room dealt with the same day is usually recoverable.
Customers find that counter-intuitive, because depth is visible and contamination isn’t. The volume tells me how much drying capacity I need. The category tells me whether drying is even the right question.
Clean water degrades, too. Water sitting in wool and jute at room temperature stops being clean water in about two days – the clock on this is hours, not days, once anything organic is involved, and a flat left over a bank holiday weekend arrives at Monday morning in a different category to the one it started in.
How long has it been wet?
This is where most salvageable carpets get lost.
The realistic window for a clean-water flood is somewhere under 48 hours from the escape to the start of proper drying. Inside that, with commercial air movement and dehumidification, a synthetic carpet on a decent underlay in a warm flat has a good chance. Past 72 hours you’re not making a cleaning decision any more, you’re making a decision about microbial growth in a material that sat wet and warm in a closed room, which is a different decision with different rules.
The trouble is that the clock nobody sees is the underlay.
What sits under there, and why nobody checks it
Lift a corner of carpet in a flat that flooded four days ago and the underlay will still be saturated when the carpet face feels dry to the hand.
Crumb rubber holds water like a sponge and gives it up slowly. PU foam does something worse – the foam breaks down, the surface goes powdery and it stops recovering under compression, so even a fully dried piece feels flat and dead underfoot afterwards. Underneath that there’s usually a concrete screed, and screed absorbs a genuine quantity of water and releases it upwards for weeks. A carpet relaid over a screed that reads high on a moisture meter comes back damp, and the customer thinks the cleaning failed.
I’ll say the unpopular thing: underlay does not survive a flood. Not clean water, not a short one, not with the best drying kit in the country pointed at it. It costs a fraction of what the carpet costs, and any firm proposing to dry it in place is protecting their own schedule rather than your floor.
Can the carpet be dried in place, or does it have to come up?
Floated drying is the middle path, and it works more often than people expect.
The carpet gets detached along one or two edges, lifted off the gripper, and an air mover is set to blow underneath so air moves across both faces at once. The underlay comes out and goes. The carpet stays broadly in position, which matters, because a fitted carpet that has been fully lifted and dried elsewhere rarely goes back down without visible stretch problems along the seams.
Alongside that, dehumidification. Air movers on their own move moisture into the room air and leave it there, and a sealed modern flat with good glazing has nowhere to put it, so without a dehumidifier you get condensation on the cold surfaces and mould on the reveals instead of in the carpet. Same water, new address.
The kit matters less than the monitoring. A hygrometer reading of the room air, a pin meter into the carpet backing at the same four points every day, and a note of what the reading was yesterday. Unmeasured drying is guessing, and guessing is how a floor gets signed off at day four when the screed underneath is still weeks from equilibrium. Insurers pay for the kit. They rarely pay for somebody to come back and read it, which tells you where the industry’s incentives sit.
Where it doesn’t work: heavily contaminated water, a hessian-backed wool carpet that has been wet for days, or a room where the plaster is holding as much water as the floor and the whole job needs a strip-out anyway. Where it does work, three to five days with the kit running, monitored with a meter rather than by feel.
The two failures that show up months later
Delamination and shrinkage, in that order.
The secondary backing on a tufted carpet is bonded with latex, and prolonged saturation weakens that bond. Nothing looks wrong for months. Then the backing separates from the primary in patches, and the carpet ripples in a way that no amount of restretching fixes, and everyone blames the fitter.
Wool does the other thing. A wool carpet on a jute secondary backing shrinks as it dries, and it can pull off the gripper along a full wall – I’ve seen a 30mm gap open up along a bay in a flat where the drying was rushed with too much heat and not enough time.
What does a flood do to the carpet you can see?
Browning, mostly, and it arrives late.
Cellulose in a jute backing degrades in water and the breakdown products wick up through the pile as it dries, depositing a tan-yellow discolouration at the tips, worst in the middle of the room where drying is slowest. It shows up three days after everyone has relaxed. It’s correctable with an acidic reducing agent while it’s fresh and it’s a real fight once it has set, and every hour of delay makes it harder.
Dye migration and the four brown squares
Anything sitting on a wet carpet transfers into it.
The pattern from a printed rug comes through onto the carpet beneath and stays there. Newsprint does it, cardboard boxes stored under the bed do it, and the feet of a cheap pine chest of drawers leave four tannin squares you can see from the doorway for the rest of that carpet’s life. Blue is the one that never comes out – a dark cotton throw left on a wet cream wool is the end of the story for that carpet.
So the furniture goes up on blocks before the drying starts, which is the opposite of the order most people do it in.
There was a garden flat off Grove Green Road in Leytonstone, E11, where the flood came from next door’s outside tap left running behind a shed. Clean water, in overnight. The tenant lifted the carpet himself the next morning, dragged it into the garden and laid it over the fence in June sunshine, which sounds sensible and was the worst possible move. It dried hard and uneven, shrank by about four per cent across the width, and the sun bleached a band across the fold. The flood hadn’t destroyed that carpet. Two days on a fence did.
What should you do in the first two hours?
Electrics off if the water is anywhere near a socket, then get the water out.
Wet vacuum if you have one, mop and bucket if you don’t, and lift what furniture you can onto blocks or upturned bowls so the feet aren’t sitting in it. Open windows only if the outside air is drier than the inside air, which in a London August it very often isn’t. Photograph everything before you move it, including a shot with something in frame for scale, because insurers ask and memory is worthless six weeks later.
The one thing worth doing that nobody does is checking the neighbouring rooms. Water travels under the gripper and along the joints, and a flood in the living room of a Hanwell ground floor in W7 turns up in the hall cupboard two rooms away without ever crossing the threshold in view.
Ring somebody the same day. Hours, not days.
What the claim will need from you
Dates, and more of them than feel necessary.
When the escape started, when it was found, when the water was stopped, when drying began. Loss adjusters build their view of a claim around that sequence, and a gap of three days between discovery and any action is the gap they lean on when they decide how much of the damage was the flood and how much was the delay. Keep the plumber’s invoice, keep the drying reports if there are any, and take a photograph of the underlay before it goes to the tip, because a claim for underlay is a great deal easier to make when somebody can see the state it was in.
The policy wording is worth reading on one point specifically: whether it covers gradual escape from a pipe or only a sudden burst. The two are treated differently, and a slow leak under a bath discovered when the carpet went black at the skirting is the version people find out about the hard way.
The meter reading on that Leytonstone screed was still above 80 per cent relative humidity a fortnight after the new carpet went down.