About this service
Concealed fittings are the parts you never see — wall-buried mixer bodies, concealed stop-cocks, diverter spindles and the rough-in plumbing that supports them. The work happens before the tile goes up, and a pressure test is non-negotiable: we run the line at 1.5× working pressure for 30 minutes before signing off, because a leaking concealed joint behind tile is a five-figure repair. Existing wall-mounted mixers that drip from the spout can usually be saved by replacing the cartridge through the wall plate without touching the tile.
Common symptoms we see
- Drip from the wall-mounted mixer spout when off
- Damp patch appearing on the wall around the fitting
- Diverter handle stiff or won’t hold position
- New bathroom build needs concealed rough-in
How we do it
- 1Survey wall and existing plumbing layout
- 2Set concealed body or replace cartridge through wall plate
- 3Pressure-test at 1.5× working pressure for 30 minutes
- 4Hand over with photos of joints before tile-up
Materials we use
Brass concealed bodies, ceramic-disc cartridges, brass diverters, PTFE tape, jute and Anabond on threaded joints.
Typical duration
2–3 hours for a single concealed body; longer for full bathroom rough-in.
Safety & quality
We refuse to seal up tile work over a concealed line that has not been pressure-tested. No exceptions.
Frequently asked questions
Can you fix the dripping wall mixer without breaking the tile?
Almost always — the cartridge is replaceable through the wall plate. We open the plate, swap the cartridge, refit. 30 minutes of work.
Damp on the wall behind a concealed valve — repair?
We pressure-test the line first to find the leak, then open just enough tile to fix it. Detailed acoustic and pressure checks come before any breaking.
How long does the pressure test really need to be?
30 minutes minimum. We watch the gauge — any drop, we find the leak before sealing up.
Pricing notes
Final price depends on site condition, materials chosen and access. The starting price covers labour for a standard install or repair; material cost is billed at actuals.
- Material cost not included in starting price
- Extra work outside the agreed scope is quoted before we start it
- Customer-supplied fittings welcome