Dye Testing for Bathroom Leaks
A stain on the ceiling under a bathroom can come from the waste, the overflow, the trap, a seal, the shower screen or the tiling. Dye testing tries each one separately so the repair is to the right part.
Dye testing, step by step
Bathroom leaks are awkward because the water only appears when the room is used, and several fittings share the same small space. A bath has a waste, an overflow, a trap, a sealant joint along the wall and a panel hiding the pipework. A shower adds a tray, a screen and grout. From the ceiling below they all look the same. Taking the tiles off to find out is a last resort, because the tiling itself may be the problem and it is costly to put back. Dye testing works the other way round, by loading one route at a time and seeing which one shows below.
We fill the bath, tray or basin and add a strong coloured dye, then release it through the waste while the ceiling or the void below is watched and moisture readings are taken. Next the overflow is tested on its own by filling above it. Then the seals and tiling are tested by running water against them without using the waste at all. Where two routes are close together we use two colours, one in the waste water and another on the seals, so the colour that appears below says which route it came through. Each stage is photographed and the readings are noted.
The test is clean and nothing is dismantled. The dye goes into the water rather than onto the surfaces, and the tiles, the panel and the floor stay in place throughout. If one route shows colour the fault is identified and the repair is usually small: a new trap, resealing a joint, replacing a waste or regrouting. If nothing shows under heavy use, the water is coming from a pipe rather than a fitting. The survey then moves on to the supply and heating pipework with pressure tests and the thermal camera. Either way you know which it is before anything is taken apart.
In our own photos
From your first call to a leak you can see in the report
Call or WhatsApp with a few photos and a line about the symptoms. We ask a handful of questions, agree a fixed price and book the survey, usually for the same or the next day.
On arrival we pressure test the mains, hot water and heating, check the meter and test the escaping water, so we know what we are looking for before the detection starts.
Thermal imaging, the acoustic ground microphone and tracer gas are used as the pipework dictates until the leak is marked on the floor or wall.
You get a written report with readings, thermal images and photographs, ready for a trace and access claim. If you want the leak fixed, we open that one spot and repair it.
A report your insurer can act on
Most buildings insurance policies include trace and access cover for finding a hidden leak and making good the way in. Our report is written for that claim: what we tested, what we found, where it is, with photographs, thermal images and readings.
- Turn off the stop tap or the heating and stop topping up
- Photograph the damage, the boiler gauge and the meter
- Tell your insurer a leak is suspected and detection is being arranged
- Trace and access pays to find the leak and make good the access
Dye tests: questions answered
How do you find a bathroom leak without taking the tiles off?
By testing each possible route separately with dyed water and watching the ceiling or void below. The waste, the overflow, the trap, the seals and the tiling are loaded one at a time, so the colour that appears below tells us which route is leaking. The tiles are not touched.
How does a dye test on a shower work?
The tray is filled with dyed water and the waste is released first. Then the screen, the seals and the tiled walls are wetted in turn while the waste is plugged, so each area is tested on its own. Colour below after a particular stage points to that part of the shower.
Can you dye test a waste pipe or drain?
Yes. Dye through a waste pipe shows whether the joint, the trap or the run beneath the floor is leaking, and the point where colour appears narrows it down. Dye added at a gully can also show whether the water reaches the inspection chamber it should.
Will the dye stain my bath or grout?
The dye goes into the water, not onto the surfaces, and the bath or tray is rinsed through afterwards. If you have a pale or porous finish you are concerned about, tell us before the test and we will plan around it.
What if the dye test shows nothing?
Then the fittings are not the cause under the load we put on them, which is useful in itself. The survey moves on to the supply and heating pipes with a pressure test, the thermal camera and, where needed, tracer gas. We tell you honestly if a leak cannot be located without opening up.
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Need dye testing?
Call now and we will tell you straight away whether it needs a same-day visit. Or send a photo of the stain, the meter or the boiler gauge on WhatsApp.
07516 755 680