Damp and mould in a flat, whose problem is it?

Whose problem is damp in a flat? It depends on the cause, and on what your lease says. That's the honest answer, and it's less helpful than it sounds, so let's make it useful.

The rough rule is simple. If water is getting in or leaking from the building's structure, roof, outside walls or shared pipes, that's usually the freeholder's or management company's job to fix, paid for through the service charge. If the damp comes from how the flat is lived in, or from something inside your own demise, it's usually yours.

"Usually" is doing real work there. Every lease is different, so the document itself is what counts. Read it before you commit.

Most long leases make the landlord, or a management company acting for them, responsible for the structure and exterior. That normally covers the roof, the external walls, the foundations, gutters and downpipes, and the shared pipes and drains that serve more than one flat.

So a few common scenarios usually land on their side of the fence.

1. 1A leaking roof causing stains on the top floor ceiling.
2. 2Blocked or broken gutters sending water down an outside wall.
3. 3Failed brickwork, pointing or render letting rain through.
4. 4A leaking communal pipe or a shared drain running through your flat.
5. 5Rising damp from a defect in the building's foundations or damp proofing, where the lease puts that on the landlord.

You don't pay for these separately in theory, but you do pay in practice. Big repairs get recovered from leaseholders through the service charge, sometimes as a hefty one-off bill. A flat with a known roof problem can come with a large cost attached, even though it's "not your responsibility".

Your lease normally makes you responsible for the inside of your flat. That means plaster, decoration, floor coverings, your own fixtures, and pipes that serve only your flat.

Condensation and mould fall here more often than people expect. Everyday life puts a lot of moisture into the air through cooking, showers, drying washing indoors and even breathing. If it can't escape, it settles on cold surfaces and mould follows. A freeholder isn't normally liable for that, unless the cause is a building defect such as poor shared ventilation or a failed extractor serving the whole block.

Things that are typically on you include a leak from your own washing machine hose, a dripping pipe that only serves your flat, blocked internal vents, and a leak from your bathroom into the flat below. That last one can get expensive, because you may be liable to your neighbour for the damage.

If you're unsure where your responsibility ends, the lease has a repairing obligations clause and a definition of what's included in your flat. A solicitor can read it with you.

Some problems don't have an obvious owner. Windows are a classic. In many leases the frames and glass count as part of the structure, in others they're yours. Same for balcony floors and entrance doors.

Cause is another grey area. A flat can have poor insulation, cold bridging or weak ventilation in the building design, which makes condensation much worse. Is that a lived-in problem or a building defect? Reasonable people, and sometimes tribunals, disagree.

Then there's the neighbour. If water is coming down from the flat above, the lease may make that leaseholder responsible, or the building's insurance may respond. The route depends on the cause and the policy.

The law and the rules around repairs and landlord duties can change, so for a live dispute check the current position with a solicitor. Don't rely on a general article, this one included.

You've got maybe twenty minutes, so use them well. Look up, look low, and use your nose.

1. 1Check ceilings, especially on the top floor, for brown rings or patches, and look at corners where walls meet the ceiling.
2. 2Look at the bottom of external walls for tide marks, peeling paint or crumbling plaster.
3. 3Sniff. A musty smell in a wardrobe, cupboard or bathroom is a bad sign.
4. 4Check window frames and sills for black mould, rot or wet sealant.
5. 5Open cupboards under the sink and look for staining or swollen board.
6. 6Look behind furniture pushed hard against external walls. It's often hiding something.
7. 7Notice fresh paint on one patch only. It might be innocent, but ask why.

Outside, look at the roofline, gutters and brickwork. Greenery in gutters, stained walls below a downpipe and cracked render all hint at water getting where it shouldn't.

A cheap damp meter can be handy, but readings can mislead, so treat one as a prompt for questions, not proof. If you see anything worrying, say so and ask for a surveyor's view.

Ask the agent and the seller plainly. Has there been damp or a leak in the flat or the building? Has anyone made an insurance claim? Are any major works planned, or already billed?

Your solicitor should ask for the management information pack, which can show service charge accounts, planned works and any disputes. Ask to see the lease too. A copy costs 7 pounds from HM Land Registry on gov.uk if it's on file.

Book a proper survey. A Level 2 or Level 3 survey will comment on damp and ventilation, and a Level 3 digs deeper on older or oddly built properties. Say it's a flat so the surveyor looks at the block and not only your four walls.

If damp turns up, it's not automatically a dealbreaker. Know the cause, get a cost, and find out who pays. Then negotiate or walk away. Either is a fine outcome.