Can you work outside business hours?

Yes, and the hourly rate does not rise for an evening or weekend visit. In offices, retail and hospitality that is usually the only way the work happens at all, and in residential blocks it is often when access to risers and communal areas is easiest to arrange.

The leak is coming from a flat we cannot get into. What can you do?

We survey everything we can reach, document what was inspected and what was eliminated, and state in the report which unexamined sources remain. That gives a managing agent or freeholder a technical document to base an access request on rather than an assertion.

Who pays when a leak in one flat damages another?

It depends on the lease and on the block policy. Typically the building fabric is insured under the block policy held by the freeholder, while the leaseholder is responsible for the pipework within their own demise. LEASE publishes free guidance on the split, and our report itemises repair and reinstatement separately so the costs can be apportioned.

Do you handle multiple properties for a managing agent?

Yes. For portfolios the value is usually consistency: the same reporting format, the same evidence standard and one contractor covering detection, repair and making good, rather than three suppliers per incident across dozens of units.

Can you find a leak under a concrete slab in a commercial building?

Yes, and it is one of the main reasons tracer gas exists. A slab defeats acoustic detection and a cold-water leak deep in concrete gives thermal imaging nothing to read. The gas surfaces through the slab above the escape point, which lets the floor be opened once, in the right place.

Is water in our basement always a leak?

No. A fair proportion turns out to be groundwater ingress or a failed tanking detail rather than a plumbing failure, and the two are distinguished by whether the meter moves and whether the water appears independently of any system pressure. If it is not a pipe, we will say so.

Repairs

Commercial Leak Repair in London

We trace, repair and reinstate leaks in blocks of flats, offices and managed estates across London, work outside trading hours where the building needs it, and issue a report written for the freeholder, the managing agent and the block insurer.

What the job includes

Identification of the responsible, insuring and access-granting parties before the first visit
Survey from the damage upward, ranking likely sources before access to other demises is requested
Section-by-section isolation and pressure testing across risers and circuits, documented as it happens
Acoustic, thermal, moisture mapping and tracer gas detection, chosen for the building construction
Out-of-hours and weekend working at the same hourly rate, to permit and induction requirements
Repair, re-run or replacement of copper, plastic, MDPE and lead pipework
Reinstatement of screed, floor finishes, suspended and plasterboard ceilings, plaster, tiling and decoration
A single report itemising repair and reinstatement separately, for the freeholder, agent or block insurer

No find, no fee · £150 per hour. The rate is fixed before we attend and does not rise for a difficult property, an awkward access or an evening visit. The total depends on how long the job takes; the rate cannot change.

What makes a commercial leak different

Technically, a pinhole in a 15mm copper pipe behaves the same in a Clerkenwell office as in a Victorian terrace. Everything around it is different.

In a managed building the water that is doing the damage is rarely in the space that reported it. The affected party, the party who owns the failed pipe, the party who insures the building and the party who can grant access are frequently four different people. Work often cannot happen during trading hours. Common parts, risers and plant rooms may need a permit, an induction or a supervised escort. And at the end of it, somebody has to be given a document that stands up when the cost is apportioned.

That is the job we are set up for: the detection and the repair, plus the coordination and the paperwork that make them usable.

Where we work

Residential blocks and mansion blocks — leaks between demises, communal risers, roof tanks, landlord's plant.
Offices and studios — kitchenette and WC core leaks, chilled and heating pipework in ceiling voids, above suspended ceilings with live IT and power below.
Managed estates and portfolios — recurring leaks across multiple units where a single contractor with a consistent reporting format saves the agent more time than the repair itself.
Retail and hospitality units — where the trading day sets the working window, not the other way round.
Car parks, basements and plant rooms — slab leaks, tank overflows, and the perennial question of whether water in a basement is a leak or groundwater.

How the job runs

Establish the parties before attending. Who reported it, who owns the pipework, who insures the fabric, who can grant access to the flat or unit above. Getting this wrong costs a wasted visit, which in a managed building costs more than the visit.
Survey from the damage upwards. The stain, the drip and the moisture map are read first, then the likely sources above and around are ranked before any access is requested. Requesting access to three flats when one would do is how goodwill runs out.
Isolate and test by section. In a building with multiple risers and circuits, the elimination sequence matters more than the detection kit. We document what was isolated and what it proved.
Detect. Acoustic, thermal imaging, moisture mapping, pressure testing and tracer gas, chosen for the build-up. Concrete slabs, screeded floors and plastic pipework are the norm in modern commercial buildings, and all three defeat acoustics, which is why gas gets used a great deal in this work.
Repair. Copper, plastic, MDPE and lead, repaired, re-run or replaced — see pipework repair and replacement.
Dry, then reinstate. Screed, floor finishes, suspended and plasterboard ceilings, plaster, tiling and decoration, by our own reinstatement team. In a let unit this is the part that determines when the tenant can use the space again.
Report and distribute. One document, addressed to the instructing party, copied where you tell us to.

Out of hours, and access

A great deal of this work cannot happen between nine and six. Offices cannot have their kitchen floor opened mid-week, a restaurant cannot lose its service, and a block will often prefer riser work when residents are out. We work outside normal hours where the building requires it, and the hourly rate does not rise for an evening or a weekend visit.

On access: we will work to a building's own permit and induction requirements, escort arrangements and key procedures, but somebody on your side has to arrange them. Where the source is behind a demise we have no right to enter, the report will state plainly what was inspected, what was not, and what the unexamined possibilities are — so the conversation with that leaseholder is based on a document rather than a suspicion. A leak from the flat above is the resident-facing version of that conversation.

The report, and who it is for

In a managed building the report usually has to do more work than the repair. Ours covers the methods used and the methods eliminated, the pressure and moisture readings, dated photographs of the site, the access taken and the failure itself, the cause stated plainly, and the remedial work itemised into repair and reinstatement — because those two lines are frequently paid by different parties.

That is what a block insurer or a loss adjuster needs to settle an escape of water claim, and what a managing agent needs to apportion a cost between the freeholder, a leaseholder and the service charge. How that is structured and what gets a claim challenged is set out under insurance claims and trace, access and reinstatement. On the leasehold split of responsibility between flats, LEASE is the free public source.

What we most often find in commercial and block property

Failed flexible tails and isolation valves under kitchenette units, which flood a floor plate overnight.
Chilled water and heating pipework weeping above a suspended ceiling, unnoticed until a tile stains.
Communal riser joints in a service cupboard nobody has opened since handover.
Roof-level cold water storage tank overflows and failed ball valves, presenting as a leak several floors down.
Wet room and shower tanking failures in newer blocks, where the water tracks along a screed before it appears.
Slab and screed leaks on plastic pipe in modern concrete-frame buildings, which is precisely the case acoustics cannot resolve.
Water in a basement that turns out to be groundwater or a failed tanking detail rather than a plumbing leak. We will tell you that rather than keep looking for a pipe.

When not to call us

A blocked or overflowing drain is a drainage contractor's job, not a leak detection one. Sprinkler and dry riser systems are specialist wet systems with their own certification regime and should go to the maintaining contractor. Anything involving gas goes to a Gas Safe registered engineer, and you can verify any engineer's registration on the Gas Safe Register. And if water is pouring into a live electrical intake or switch room, that is an isolation and safety call before it is a plumbing one.

What it costs

The same hourly rate as every other job, fixed before we attend and not increased for an evening, a weekend or a difficult access. The total depends on the size of the building, how many circuits and demises have to be eliminated and how much reinstatement the affected space needs, so it is scoped on site rather than quoted blind. If we do not find the leak, you do not pay for the time we spent looking. Terms on the pricing page.

Frequently asked

Can you work outside business hours?: Yes, and the hourly rate does not rise for an evening or weekend visit. In offices, retail and hospitality that is usually the only way the work happens at all, and in residential blocks it is often when access to risers and communal areas is easiest to arrange.
The leak is coming from a flat we cannot get into. What can you do?: We survey everything we can reach, document what was inspected and what was eliminated, and state in the report which unexamined sources remain. That gives a managing agent or freeholder a technical document to base an access request on rather than an assertion.
Who pays when a leak in one flat damages another?: It depends on the lease and on the block policy. Typically the building fabric is insured under the block policy held by the freeholder, while the leaseholder is responsible for the pipework within their own demise. LEASE publishes free guidance on the split, and our report itemises repair and reinstatement separately so the costs can be apportioned.
Do you handle multiple properties for a managing agent?: Yes. For portfolios the value is usually consistency: the same reporting format, the same evidence standard and one contractor covering detection, repair and making good, rather than three suppliers per incident across dozens of units.
Can you find a leak under a concrete slab in a commercial building?: Yes, and it is one of the main reasons tracer gas exists. A slab defeats acoustic detection and a cold-water leak deep in concrete gives thermal imaging nothing to read. The gas surfaces through the slab above the escape point, which lets the floor be opened once, in the right place.
Is water in our basement always a leak?: No. A fair proportion turns out to be groundwater ingress or a failed tanking detail rather than a plumbing failure, and the two are distinguished by whether the meter moves and whether the water appears independently of any system pressure. If it is not a pipe, we will say so.