Anna Kettle wrote:
Tanking doesn't have to be very expensive.

I don't think thats true though

Covering the walls in thin polythene dust-sheets will stop the water
evaporating into the room.
I'd personally go with something like making a very simple frame to hold
the dustsheets a couple of inches off the wall, and a fan to blow air
from the room through this space out a vent.
snip
I would just limewash the walls

What would this do?
I thought limewash was basically just a porous white 'paint'.

Is this not so?