Exposed pipework is easier, right up until it is not
The appeal of a warehouse conversion is that nothing is hidden: brick, timber, steel and services on the surface. For leak work that is genuinely helpful. A weeping compression joint on a surface-run copper pipe is visible, reachable and repairable in twenty minutes, which is not true anywhere else in this list.
The catch is that the exposed portion is only part of the installation. Everything that had to cross the floor plate, feed a bathroom pod, or drop to a waste connection went somewhere less convenient. In these buildings that means one of three places: cast into a structural or levelling screed over the original slab, boxed into a stud that was built specifically to hide it, or run within the floor build-up of a mezzanine.
So the diagnosis splits immediately. Walk the exposed runs first, properly and with a torch, before anyone books a detection visit. A surprising number of these jobs end there.
The slab, and why there is nowhere for water to go
A Victorian or Edwardian industrial building has heavy floors: concrete on steel or jack-arch construction, sometimes thick timber on deep joists. When it was converted, the new plumbing rarely got a void to live in, so it was laid on the structural floor and buried in a levelling screed, or run in a shallow build-up under new boarding.
The consequences when something fails:
- Water travels a long way horizontally. A dense slab is effectively impermeable, so the escape spreads across the top of it under the finish until it reaches a penetration, a movement joint or an edge.
- The wet patch is not above the leak. In an open-plan space with a single large floor plate that can mean metres, not centimetres.
- The finish is often the problem. Polished concrete, resin and large-format tile are all difficult to open neatly and nearly impossible to match invisibly. That raises the value of precise location enormously.
- Drying is slow. Screed over a cold slab holds water for a long time, which matters for the insurance claim and for whatever goes back down afterwards.
Thermal imaging works well on a heating or hot water leak in a screed because the contrast is strong. For a cold water loss under a slab, tracer gas on the drained section is the method that actually resolves it.
Systems in these buildings that are not plumbing
This is worth its own section because warehouse conversions contain more non-plumbing water than any other residential building type.
Sprinklers and dry risers
Many conversions, particularly larger ones and anything with a long escape route, are fitted with sprinklers. Sprinkler pipework is a life safety system maintained under its own regime by specialist contractors, and it is not something a plumber should isolate, drain, repair or even open a ceiling to inspect. If the water is discoloured, if it is continuous, and if there is an alarm panel showing a pressure fault, stop and call the building manager. We will not work on it.
Comfort cooling condensate
Ceiling-mounted or high-level cooling units produce condensate, which is piped away, usually to a pumped drain. Blocked condensate drains produce clean water in warm weather and nothing in winter, appearing near a unit. It is misdiagnosed as a plumbing leak constantly.
Roof drainage inside the envelope
Industrial buildings often have internal rainwater downpipes taking water from a large flat or valley roof down through the occupied space. A failed joint on one of those produces a spectacular leak that correlates exactly with rainfall and has nothing to do with the plumbing.
The test that separates all three from plumbing is the same one that works everywhere: isolate the water supply at the stop valve, check the heating pressure, and see whether the water continues. If it does, it is not the plumbing.
Long runs, dead legs and the problems of a big floor plate
A converted floor plate is wide, and the plumbing that serves it inherits that geometry. Long horizontal supply runs from a single riser to bathrooms at the far side of the unit create their own failure modes.
- Dead legs. Branches that serve an outlet used rarely, where water stagnates. A hygiene issue rather than a leak, but worth flagging on any survey.
- Expansion. Long runs of plastic pipe move significantly with temperature. Where they were clipped rigidly at both ends with no allowance, the stress goes into the joints.
- Inadequate support. Sagging horizontal runs above a ceiling or within a floor build-up open joints at the low point and hold water there.
- Waste falls. Getting fall across twenty metres of a converted floor to a fixed stack position is difficult, and the result is often a run that barely clears itself.
Before anyone opens anything
Two things are worth chasing down first, and they are both paperwork.
The conversion drawings. Somebody has a set showing where the services were run, and in a building converted in the last thirty years they usually still exist with the managing agent or the residents' company. Ten minutes with a drawing beats two hours with a thermal camera.
The asbestos position. Asbestos can be present in any building constructed or refurbished before 2000. In an industrial building of this age the materials HSE list are all plausible: sprayed coatings for fire protection on structural steel, lagging on pipework, asbestos insulating board, asbestos cement products, and floor tiles with associated sheet and screed materials. A sprayed coating on a steel beam above a ceiling is a genuine reason not to open that ceiling casually. Ask the managing agent for the survey before work starts.
What we do here
We trace the leak, we repair the pipework, and we reinstate the screed and the floor finish where we have had to open it. On a polished or resin floor we will tell you honestly before we start what a repair will look like, because an invisible patch in a polished slab does not exist and it is better to know that in advance.
If water is running now, emergency leak repair is the starting point, and burst pipe covers what to do in the first ten minutes. Detection is charged at £150 an hour, agreed before we attend, with no charge for the search time if we do not find it.
