Home › Hidden Leaks
No flood, no drama — just a damp patch, a musty smell, or pressure that won't hold. This briefing is about catching it before it's a bigger job.
Suspect a hidden leak, confirm it, then act. Close the main stopcock, make sure nothing's using water, and watch your water meter (if you have one) for an hour or two — movement with everything off means water is escaping somewhere. Found a damp patch, a musty smell or falling boiler pressure that fits? Ring 020 4577 2888 any hour and describe what you've noticed.
Damp patches, musty smells, falling boiler pressure, an unexplained rise in the water bill. Any one of these on its own is worth a look; two together are worth a call.
None of these confirm a leak on their own — but any of them is reason enough to run the stopcock test below rather than wait and see.
Everything off, note the meter, close the stopcock, wait, check again. Movement on the meter with the house silent is the tell.
No meter on the property? The same logic still works in a rougher form: close the stopcock, leave every tap shut for a few hours, and see whether damp patches or boiler pressure keep worsening regardless. If they do, the fault likely sits on the supply side rather than inside your own pipework.
Stops with your stopcock closed: yours. Continues, or shows outside your boundary: likely NI Water's. The same boundary principle as a burst pipe, just slower.
The general split in Northern Ireland runs the same way for a slow hidden leak as for a sudden burst: everything from the property boundary inward is the owner's responsibility, while the public main beyond the boundary belongs to NI Water. A leak that fits your stopcock test — stopped once the stopcock's closed — is inside your own system. Water surfacing outside your boundary, a permanently soggy verge near the road, or a leak that continues despite your stopcock being shut, points at the supply pipe or the public main instead.
Along the older terraced stretches of Cookstown's main street especially, supply arrangements between neighbouring properties can be genuinely tangled, so get whoever attends to confirm plainly which side of the boundary the leak sits on before repair talk starts — a straight plumber will tell you honestly when it's a job for NI Water rather than their invoice.
Because it doesn't stay small. A slow leak rots timber, feeds mould, corrodes pipework from outside, and quietly runs up a metered water bill the whole time it's ignored.
A drip that never puddles can still sit inside a wall cavity or under a floor for months, soaking into timber and plasterboard long before it ever shows as a visible stain. By the time a patch appears on a ceiling, the leak behind it has often been running for a while — which is exactly why the signs in the first section are worth acting on early rather than waiting for something dramatic.
There's a cost dimension too: on a metered supply, even a small continuous leak adds up steadily across weeks, and boiler pressure that's constantly topped up is doing the same thing to your heating system's efficiency. Catching a hidden leak at the damp-patch or falling-pressure stage is nearly always cheaper and less disruptive than catching it once it's a hole in a ceiling.
Make sure no taps or appliances are running, note the reading on your water meter if you have one, then close the main stopcock fully and leave it shut for an hour or two without using any water. Check the meter again afterwards — if it's moved with everything off, water is escaping somewhere between the meter and your fittings, even with the stopcock closed downstream of an internal leak.
An intermittent patch often points at a leak linked to use — condensation from a cold pipe, a shower tray seal that only weeps when the shower runs, or a leak that only shows under mains pressure and dries between uses. Note exactly when it appears (after a shower, after rain, after the heating fires) and report that pattern; it narrows the search significantly.
Yes, if your property is on a water meter — a leak running continuously, even a small one, adds up over weeks and shows as unexplained usage on the bill. An unusually high reading with no obvious change in household habits is worth investigating with the stopcock test above, ideally before the next bill arrives rather than after.
Yes — a persistent musty or damp smell, especially near a bathroom, kitchen or under-stairs cupboard, without any visible staining, can mean a slow leak inside a wall cavity or under flooring that hasn't broken through to a visible surface yet. Catching it at the smell stage, before staining appears, usually means a smaller repair.
The main page — how the line works and the patch it covers.
Go to home →Isolate, drain, make safe — the first five minutes in order.
Take the briefing →Pressure drops, lockouts, oil and gas — and the gas hold point.
Take the briefing →What you're cleared to try, and when it's NI Water's sewer.
Take the briefing →Hedged ballparks and the questions to ask before work starts.
Take the briefing →Switches, controls, pressure, oil, immersion — in order.
Take the briefing →Gentle thawing done right, and the lagging that prevents it.
Take the briefing →Ring any hour and describe what you've found — a local plumber covering Cookstown and the townlands takes it from there.
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