No, it’s not the latest embarrassing stunt in the Big Brother house – Gareth’s shower really is outdoors. Wait, wait, that can’t be right… no, it’s just a spare bath he has kicking around. As you do.

Anyway, the question is… how does your shower work, when it’s usually upstairs, and the water for it comes through pipes underground?

Down we go, following the hosepipe…

…to the source of Gareth’s water. Remember, his shower is way up:

there, while his water is right down:

here, in this water barrel.

There it is. Water, of course, likes to flow downhill. So this water is staying putt in the barrel, which doesn’t make for the most impressive shower. Now, you could pump it upstairs, but that would take a huge amount of energy.

A better plan is to lift up the water barrel.

Higher, higher, higher… until the barrel is higher than the shower. And then:

the water can flow all the way down the pipe, up the stairs, and out of the shower, but still have gone downhill overall. So it flows out of the shower head.

The higher the barrel, the higher the pressure from your shower.

Amazingly, this is exactly how your home water supply works. Most of us get our water from reservoirs, and reservoirs are deliberately built high up, so the water pressure throughout the system is more than enough to push the water out of your shower upstairs.

So that’s how you get your water upstairs.