In the living room of my son's middle floor tenement flat, damp appeared in the corner of an internal wall, external wall and ceiling. Turned out that upstairs had a rising mains leak which was eventually fixed late 2022.
However, both walls about 1m each in from the corner were damaged. The attached picture shows some of the streaking and lines on one of the walls. We understand there was cavity wall insulation inserted in the light purple wall well before my son bought the flat. The leaking was a sort of guey substance which then dried with a crust. We let the walls dry then scraped some parts back to the very original plaster coat and some parts just sanded. They seemed to be dry and I then painted two coats of Zinsser bin allowing it to dry in between coats.
A few days later some bubbling appeared then we got some yellowish drips on both walls which appeared to be coming from the larger bubbles. Depressing the smaller bubbles brought out some small amounts of fluid. There are bubbles appearing all over the affected areas.
We're really not sure what to do with the walls. I've never had this sort of issue with zinsser bin before. I'm guessing that perhaps the walls weren't fully dry despite leaving them for a couple of months and sanding them. The cause of the leak was fixed months ago. I'm now in the process of scraping everything back to plaster where possible.
Wondered if anyone has any ideas please ?
Would a damp proof paint work if painted on a surface which appears dry but perhaps isn't ?
Which dampproof paint would recommend ?
Thanks
However, both walls about 1m each in from the corner were damaged. The attached picture shows some of the streaking and lines on one of the walls. We understand there was cavity wall insulation inserted in the light purple wall well before my son bought the flat. The leaking was a sort of guey substance which then dried with a crust. We let the walls dry then scraped some parts back to the very original plaster coat and some parts just sanded. They seemed to be dry and I then painted two coats of Zinsser bin allowing it to dry in between coats.
A few days later some bubbling appeared then we got some yellowish drips on both walls which appeared to be coming from the larger bubbles. Depressing the smaller bubbles brought out some small amounts of fluid. There are bubbles appearing all over the affected areas.
We're really not sure what to do with the walls. I've never had this sort of issue with zinsser bin before. I'm guessing that perhaps the walls weren't fully dry despite leaving them for a couple of months and sanding them. The cause of the leak was fixed months ago. I'm now in the process of scraping everything back to plaster where possible.
Wondered if anyone has any ideas please ?
Would a damp proof paint work if painted on a surface which appears dry but perhaps isn't ?
Which dampproof paint would recommend ?
Thanks
