During the first few minutes, the aim is to limit the damage and protect people. If it can be done safely, shut off the water supply concerned, move people away from any electrical risk and warn the occupants directly affected. The question of liability comes afterwards.
First question: do you know where to shut the water off?
If the leak clearly comes from your home and you can identify the relevant stopcock, close it.
The moment a hose bursts is not the moment to discover your flat's plumbing for the first time.
And if the water is reaching an electrical installation?
Do not handle electrical equipment in a wet area if you do not know exactly what you are doing.
Where there is an immediate danger to people, the emergency services come before managing the file.
Who should be warned straight away?
The occupants directly at risk: the neighbour below, the adjoining premises or anyone present in the affected area.
Then comes the contact the building has provided for: syndic, caretaker or technical contractor, depending on how the co-ownership is actually organised.
The syndic is not automatically a technical helpline available twenty-four hours a day.
Is a leak inside my flat always a private matter?
No.
The law presumes common those sections of pipework attached to a common installation, even where they run through private premises. (loi du 16 mai 1975, art. 3.2)
Where the water appears is therefore not enough to establish who is liable.
What is the syndic's role if a common part is involved?
The law entrusts it with the preservation, safekeeping and maintenance of the building, together with the power to start the urgent works needed to safeguard it. (loi du 16 mai 1975, art. 21)
Where urgent works are started on its own initiative, the regulation then governs how the co-owners are informed, the calling of a meeting and the advance payment that may be requested. (RGD du 13 juin 1975, art. 27)
Why take a few photographs?
Because the state of the premises changes as soon as anyone starts mopping, repairing or dismantling.
A few images of the visible source and of the affected areas can help explain the incident later on.
But they must never delay a safety measure or the stopping of the flow.
And the insurance?
Once the situation is stable, follow the procedure set out in the contracts concerned.
Notification periods and contacts vary from one contract to another. There is no single procedure valid for every co-ownership.