After the old bathroom has been gutted and the space has been cleaned, we move on to the most critical stage of the infrastructure: the installation of the new plumbing and electrical network. These are the "arteries" and "nervous system" of your bathroom.
If a mistake is made at this stage, correcting it after the tiles are installed will cost thousands of euros. Here, the plumber and the electrician must work together with surgical precision, as the coexistence of water and electricity in a wet space requires strict adherence to safety regulations.
In the old installations, the pipes ran from one wall to the other with continuous joints and corners (tau, muffs) hidden in the plaster. Any such joint is a potential point of future leakage.
In the modern renovation, the installation is done by the "pipe-in-pipe" method (pipe in a pipe) through a central collector. The collector is placed in a hidden place (eg under the furniture or in a special glove box) and from there a separate, one-piece pipe starts for each device (one for the basin, one for the shower, one for the washbasin). Thus, there is absolutely no joint inside the walls.
Laminated or cross-linked polyethylene (PEX) pipes with strong insulation are used. They are resistant to high temperatures, do not catch salts (puri) and dampen the noise from the flow of water.
The old lead or plastic floor drain is replaced with a new, heavy-duty PVC one with a non-return valve (to prevent odors). The drainage pipes of the basin (Φ100) and the sinks/showers (Φ40 or Φ50) are installed with the correct angle of fall.
The bathroom is strictly divided into Protection Zones (Zones 0, 1, 2, 3) based on the European regulation HD 384, depending on the distance from the water source (bathtub or shower).
At the same time, the electrician draws new, reinforced lines (2.5 mm² cables) for the operation of the washing machine, the water heater or the electric towel rail.
Any 230V switch or socket is prohibited. Only low-voltage waterproof lamps (up to 12V) with a waterproof index of at least IPX7 are allowed.
Only special lamps (IPX4) and sockets for shavers with isolation transformer are allowed.
Normal sockets can be placed here (e.g. for a hair dryer or washing machine), but they must be sealed with a cover (IP44) and covered by the general Safety Relay (SSR) of the electrical panel.
This is the most critical step of Phase 2. Once the plumber has completed the connections, he is not allowed to close the walls.
Places special plugs on all waits and connects a manual or electric pressure pump (press). It fills the network with water and raises the pressure to 10 to 15 bar (about 3-4 times higher than the normal pressure of the city network).
The installation is left under this pressure for at least 24 hours. If the manometer (the pressure indicator) does not drop at all, it means that the network is 100% watertight and safe to cover with plaster.
| Technical Rule | Correct Practice | Malpractice (Dangerous) |
|---|---|---|
| Digging Direction | Strictly vertical (vertical) routes. | Long horizontal grooves that "cut" the bricks in half. |
| Concrete Elements (Feron Agency) | Passage of pipes in front of the concrete (with subsequent plastering or plasterboard). | Digging into columns or beams and cutting rebar. |
| Intersection of Pipes/Cables | The cables always go above the water pipes (never below, in case of leakage). | Random crossing and contact of bare tubes with cable spirals. |
> ⚠️ The Engineer's Tip: Once the plumbing and electrical lines are complete and before the plasterer arrives, take detailed photos and videos with your phone. Keep the corners of the walls as a reference point. In 3 years, when you want to drill a hole in the wall to hang a mirror, toilet paper holder, or shelf, you'll open the photos and know exactly where a pipe or cable goes so you don't drill them.
In the next article we move on to Phase 3 - Masonry Repair & Plastering. We will see how they properly close the channels that have been opened and why the absolute "levelling" of the walls is the only way to avoid problems with the slab later on.
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