Bitumen latex on cellar wall

[niedzwiedz]

Help! Am tidying up my cellar which is reasonably dry but shows signs of damp where the edge of the outer walls meets the floor. Before repainting I scrubbed down the old brickwork, used a fungicidal wash and put brick stabiliser on it to sort out some crumbly brick and stone, then put a coat of AquaSeal Hyprufe bitumen latex on prior to painting. Now, I have not yet painted over the bitumen (I have an oil-based cellar paint waiting)...but I see a couple of small areas of white mould forming on the wall. I suppose this is what you get for naively reading a DIY book and the side of a tin.

I am guessing that this mould is coming through a small gap in the bitumen...question is, what to do. Should I try to sort this out with some fungicide? Should I give it more latex over the gaps, or is the latex the problem? Would a more robust tanking solution e.g. Thoroseal or equivalent stick to the wall due to the bitumen?

No idea how I would remove the bitumen latx if it came down to that - it would be hard to get a machine down there. Any thoughts or advice would be very welcome!

 

[DonJenzus]

Hi

Possible to get a picture?

It could be just the minerals from the wall.
The best way to make sure if it is minerals or mould is to fill a glass with water. Then scrub some of the white stuff from the wall and put it into the glass. If it dissolves into the water, it´s minerals. If not then it´s mould.


The thing that i´m wondering the most is why do The Brits use these waterproof stuffs inside the buildings. Usually the cellars (at least in Finland)
were made to dry inside. How old is your house? Does it have some kind of a coating outside the wall? If so, is it water proof also. If it is, you shouldn´t make it water proof from both sides, since all the moisture coming from underneath the house would just rise along the wall as long as it needs to get out of there, possibly just moves the moisture to the next floor.

 

[Deluks]

I see a couple of small areas of white mould forming on the wall.

Most likely condensation forming on the now vapourproof wall.

Tanking a cellar and making it habitable isn't as easy as just painting stuff on the wall. All rooms in a house need adequate ventilation, and I suspect the stagnant air in the room is causing the mold to feed on the moisture collecting on the surface, where before it would have been absorbed into the brickwork.