Plumbing: pressure testing and checks before boxing in

Why check now

After tiles and boxing, a leak is found only by a stain at the neighbors' below. Opening up the finish costs more than checking the pipes while they are in sight. In the app route the “Plumbing” stage usually comes right after partitions and before electrical, and the test items come last in it - before the stage is accepted.

What is done at the “Plumbing” stage

First the points are marked and the pipes run, then outlets for fixtures are prepared, and only at the end is everything tested.

Marking and pipework

• Mark the plumbing points from the finished floor level mark and walk through the marking with the owner or designer before the first chase is cut. Dimensions are checked against furniture and doors.
• Manifold assembly - manifolds, filters, pressure reducers, shut-off valves. Easy access is left to it through an access hatch.
• Water supply pipes - hot and cold pipework; the routes are photographed before the walls are closed.
• Drain lines - pipes with the required slopes. Slopes are checked before boxing in.

Outlets for fixtures

• Toilet frame - the frame and connections for a wall-hung toilet; the height is best agreed in advance. Master Kistya's tip: the frame's feet go on the monolithic floor slab, not on the developer's screed - the screed in that spot is carefully removed.
• Bath or shower - outlets for the chosen bath or shower tray model, with the size and drain position known in advance.
• Concealed mixers - the bodies are set at a depth based on the finished wall, allowing for plaster, adhesive and tiles. The depth is checked against the manufacturer's instructions: once tiled, the body can't be moved.
• Exposed mixers - the distance between outlets matches the chosen mixer, usually 150 mm.
• Bidet shower - with a mixer and a check valve.
• Water heater, water filter, waste disposer, washer and dryer - outlets and room for servicing; for the water heater and disposer, power is planned too.
• Leak protection system - valves, controller and sensors; sensor locations are planned in advance.
• Hydronic towel rail - outlets with a bypass and valves. Moving it on the hot water riser is a building alteration, only through building management.

Pressure test: how to check the water supply

The route item “Pressure-test the system”: check all joints for leaks under pressure and photograph the pressure gauge at the start and at the end of the test. If the pressure has dropped, the leak is found before the pipework is closed up.

What it looks like in practice:

1. The plumber fills the system with water and raises it to the test pressure.
2. You or the plumber photograph the gauge - the photo shows the needle and the time.
3. The system is left under pressure for the duration of the test.
4. The gauge is photographed again. If the needle hasn't moved, the joints hold.
5. While the system is under pressure, every joint is inspected and felt: it should be dry underneath.

The test pressure and how long to hold it depend on the pipes and fittings: they are set by the design and the manufacturer's instructions. Ask the plumber what pressure and how long they test for, and write it in a comment on the item. If a company does the plumbing, ask for a test report: it will help if you later have to argue about the warranty.

Flush-testing the drains

The item “Flush-test the drains”: run water through every drain and make sure it flows away freely and the joints stay dry. It's done before the boxing and screed close everything up. Master Kistya's tip says the same: before the pipes are hidden, run water and check that no joint leaks.

What to look for:

• water leaves every outlet at once, without gurgling or backing up;
• joints and sockets are dry;
• there is a slope along the whole pipe, with no sagging or reverse sections.

Heating, if it was touched

If radiators were moved or replaced, check the slope of their connections. Under SP 73.13330.2016 (clause 6.4.1), connections to heating appliances are laid with a slope of 5-10 mm over the length of the connection in the direction the coolant flows. Replacing and moving radiators in an apartment building is agreed with building management: without valves and a bypass, a removed radiator leaves the whole riser without heating. These are Russian standards; other countries have their own.

Photos before closing up

The item “Record the result”: photograph all pipes, manifolds and outlets before they are closed up - each wall in full, a tape measure from the floor or a corner in the shot, label the room. The contractor takes the photos before plastering and boxing, the owner or designer reviews them. Master Kistya's tip: in a few years these photos will be your map of hidden utilities - you drill by them without hitting a pipe. What else to photograph before closing up is in Photos of hidden work.

Plumbing acceptance checklist

• The marking of points is agreed with the owner or designer.
• Manifolds, filters and valves are reachable through an access hatch.
• The toilet frame stands on the floor slab, the height is agreed.
• Concealed mixer bodies are at the depth of the finished wall.
• The pressure test is passed: two photos of the gauge, the pressure didn't drop.
• Every drain is flush-tested, joints are dry, slopes are there.
• All pipework is photographed with a tape measure in the shot.
• The test report, if there was one, is kept in the documents.

How to run it in the Doma app

In the “Plumbing” stage the items go in the same order. The contractor checks off “Pressure-test the system”, “Flush-test the drains” and “Record the result”, attaches photos and taps “Send for review”. You look at the photos of the gauge and pipework and accept the work or tap “I have remarks”. How the review works is in Review and acceptance of work, and the overall stage-by-stage approach is in How to accept a crew's work.