About a month before Christmas I put 2 coats of KA tanking slurry on the interior of a single skin walled outbuilding (coal shed attached to house) - halfway up walls and over whole floor - as these walls have always been damp as the DPC is bridged but a concrete shed base in a neighbours garden which has been there for 8 years before we moved in.
(Obviously the best course of action would be to resolve the bridging by digging up the shed base and providing adequate drainage and a damp proof membrane on the outside of the building but this could not be done for 'diplomacy reasons')
All has been well, although today has been a miserable day and it's been raining most of the day and I noticed water on the inside of the walls again - does this mean my tanking has failed?
After this I had planned to batton out the walls at 400mm spacing and put 25mm celetex in each gap with foil tape sealing off between the battens and 12.5mm moisture resistant plasterboard on top of this - I do not intend to drill holes though the tanking slurry to fix the battons on the bottom half of the wall and had intended to fix with a grab adhesive.
The floor I have created 18mm ply panels which I also intend to put celetex under when it is back in stock at wickes
The only other thing I am thinking is that perhaps the tanking slurry hasn't fully cured yet?
Cheers