The Gravel Was Laid Last Week: Five Drain Warnings Hiding in Plain Sight on North West Viewings

Most drain problems introduce themselves politely — a smell, a gurgle, a wet patch on the patio. The expensive ones have usually been tidied away before the estate agent's photographer turned up. We get called to a lot of recently purchased houses across the region, and the same handful of tells keeps appearing: in Stockport semis, Wigan terraces, Wirral bungalows and the newer estates out Chorley way alike.

None of these flags automatically means walk away. Most are a few hundred pounds to put right, and a few are worth a sensible conversation with the seller. Here's what to look at.

1. Gravel that's suspiciously new

A fresh layer of gravel over a front garden, driveway edge or strip of lawn is the cheapest and fastest way to disguise a collapsed gully, a cracked chamber or a soakaway that has quietly become a pond. If the stone looks brighter than the rest of the street, take a closer look at what it's covering.

What to do: find the gully. There should be a grated pot at the lowest point of the drive or hardstanding, usually near a downpipe. If there isn't one, ask where the surface water actually goes. Indicative 2026 costs: a replacement gully and surround runs £200–£450; rebuilding an inspection chamber £800–£1,500; a new soakaway £2,000–£4,500 depending on ground and access.

2. There's no inspection chamber you can actually find

Every older property should have a rodding eye or chamber somewhere, and newer ones should have at least one accessible chamber. When you can't find it, it's usually under a deck, beneath artificial grass, or paved over during a patio job.

This matters more than most buyers realise. If the chamber is shared with next door — very common on Victorian and Edwardian terraces — you've also got a responsibility question to untangle. Sealing a shared chamber under a permanent structure is the sort of thing that becomes an argument later.

Ballpark: raising or replacing a cover £150–£400; locating and rebuilding a buried chamber £400–£900. If it turns out to be a public sewer, that's a conversation with United Utilities rather than your wallet.

3. Slow sinks, gurgling plug holes and the phrase 'it's always done that'

Gurgling is air being pulled through a partially blocked pipe. Slow is the same blockage further along. The honest answer is often years of fat, wipes and soap gunk, and a decent jet wash sorts it.

But it can also be a fall that was never right, a root mass at a joint, or a pipe that's bellyed where the ground has settled. Ask when it was last cleared and by whom. A seller who can produce a receipt from two years ago is telling you something useful; one who says it's always done that is telling you something else.

Ballpark: high-pressure jetting £90–£180; a CCTV survey £150–£300; a localised structural liner £350–£700.

4. A stripe of bright green grass in August

Lush, oddly cheerful grass during a dry spell often means something is leaking a few feet below and feeding it. Look for a sunken patio corner, a dipped section of drive, or a patch that stays wet days after rain.

A soakaway that has silted up shows itself the same way — water sitting on the surface of a lawn long after the downpour. Neither is catastrophic, but both are money.

5. Air fresheners everywhere and a whiff in the hallway

Plug-ins in every room of an empty house are a business decision, not a lifestyle choice. Add a couple of rat bait boxes by the back door, a drain covered with a plastic bag, or a gully sealed with silicone, and you've got a property where someone has been managing a smell rather than fixing a cause.

Ask directly, in writing, through your solicitor: have the drains ever backed up, and has any remedial work been carried out? You'll either get a straight answer or a very useful silence.

When it's worth insisting on a CCTV drain survey

A HomeBuyer report typically notes that drains were not tested. That's not negligence — it's just outside the scope. If you've spotted any of the above, the property is 1930s or older, there are big trees within five metres of the line, or the plot has had a previous life as a garage, yard or workshop, get a proper survey done before exchange.

Expect to pay £150–£300. You should receive a video, a report with a plan and metreage, and a clear description of any defects. Ask the vendor's permission for access in writing; it's rarely refused, and a refusal is itself information.

Using the findings without scaring yourself off

Get three quotes for the remedial work, then use the middle one. Ask for the cost of putting it right, not a vaguely terrifying headline figure. In practice, most buyers negotiate somewhere between half and all of the remedial cost, or agree a price reduction — and for anything under a few hundred pounds, it's usually quicker to just crack on.

What you shouldn't do is demand ten thousand pounds off because a camera found a bit of root. Proportion is everything, and a good solicitor will tell you the same.

The genuine walk-aways

Rare, but real: a culverted watercourse running under the house without any easement; a private sewer serving four neighbours that's collapsed, with no agreement on who pays; a drain that only runs beneath next door's extension; or no legal right to discharge anywhere at all. Those are legal problems dressed up as plumbing, and they're worth proper advice.

For everything else, a couple of hundred quid spent before exchange is the best-value survey in the whole house-buying process.