In school they have these shower rooms which is just a room which you can lock and there’s a shower in there, there’s no toilet there. The question is, can we perform prayer in these rooms or would it be considered a room that’s unclean and not permissible for prayer?

by

As long as you are pure and the place on which you do sujud is pure, and you don’t know that the ground is najes and that it made you najes, the Law of Purity applies and the prayer would be valid there.

If you know the ground is najes and the ground is moist or your body is moist, then you will become najes and your prayer will be invalid. But if you don’t know that the ground is najes, you may consider it pure and you can pray.