A pipe has burst. Here is the first five minutes.

1. Stop the water at the main valve

Find the main shut-off before you need it, and tell everyone in the house where it is. On most properties here it sits next to the water meter, at the boundary or just inside the gate, under a small concrete cover. It is usually a lever or a round handle. Turn a lever a quarter turn so it sits across the pipe; turn a wheel clockwise until it stops.

If the leak is at one fixture rather than in the walls, there may be a smaller valve under the sink or behind the toilet. Closing that keeps the rest of the house in water.

2. If there is no valve, stop the supply at the tank or the pump

Plenty of homes here are not plumbed from a pressurised main. If yours fills a tank, or a pail-flush bathroom is fed from a drum, there is nothing to close: cut the pump instead, at its switch or its breaker, and stop refilling.

This is the step every guide written abroad leaves out, because it assumes a valve and a tank toilet. The question is not where the tap is. It is what is pushing the water.

3. Kill the power to anything the water can reach

Water on the floor near an outlet, an extension cord, a pump or a water heater is the part of a plumbing emergency that actually hurts people. Switch that circuit off at the breaker, not at the appliance.

If the water has already reached a socket or the breaker box itself, do not wade in to reach it. Stay out of the room and ring an electrician as well as us.

4. Take the pressure off

With the supply closed, open the lowest tap in the house and let what is left in the pipes run out into a pail. That drains the system downwards and away from the leak, and it stops a slow drip continuing for another twenty minutes after you thought you had stopped it.

5. Photograph it before you mop

Four pictures, before anything is moved or cleaned:

• The leak itself, close enough to see where the water is coming from
• The same spot from far enough back to show which room and which wall
• The meter face, including the small red dial, if the meter is running
• Any damage to a ceiling, a cabinet or flooring, while it is still wet

These are the pictures that let whoever answers the phone bring the right parts, and they are the ones an insurer or a landlord asks for later, when the floor is dry and nobody can prove anything.

6. Then ring somebody, and say these four things

Where the water is coming from, if you can tell. Whether you managed to close the supply. Whether any of it has reached electrics. And what kind of building it is, because a two-storey house, a condo unit and a row of shops are three different jobs.