Inside of Tanking Wet

[Guitar_man]

Ive recently tanked a lower section of a wall, but noticed today after heavy rain the tanking is attracting the moisture. So the inside of the tanking is wet, but not the cement render. Does tanking attract condensation but the cement render is absorbing the moisture, im thinking as the tanking is waterproof, you are seeing internal condensation on it as it cant escape into the wall. Hardly ideal!
Any ideas?
Thanks.

 

[Flyboytim]

What is directly on the other side of the tanked wall?

 

[Guitar_man]

Nothing, it is an outside brick wall.
I reckon that once the foil backed plasterboard is attached to the wall, then there won't be condensation as it won't be able to reach it. I guess it's a n indication of how much water vapour is being absorbed into the raw render.

 

[Flyboytim]

This is daft!

Outside brick wall, above ground, rendered, tanking, then condensation. Of course there will be condensation!! There is nowhere else for the water vapour to go!!

You need to change the mindset that impermeable means dry!!

Impermeable means that the water stays inside if that is where it comes from. If it can't get out it will condense.

Remove render and tanking. Leave brick wall for three months - April - then apply a breathable lime plaster. http://limecrete.net/ is a great place to start.