Hi all, need your help in identifying what is wrong with my wall. During reno, my contractor said he helped me applied some waterproofing solution to this wall under my study table (the exterior wall is directly exposed to the elements) without consulting me. At the time, whatever they applied to the wall, it stained the wall in bright yellow greenish and brown colour. Didn't think much of it as I thought it would be painted over.

However now we are in rectification phase, and they have spent hours of manpower scraping and painting over the wall and within hours the stain will just come back. It's very frustrating and the keep saying they will solve it but I'm wondering if anyone has any idea what's going on or ideas to solve? Thank you.


1.Before reno, the wall had issues.

2. After application of the unknown solution during reno.


3. Current situation, after multiple attempts to paint it over.


++Update++

Updated with pictures of wall from the other side.

The black floor tiles were added in by my contractor as a sort of barrier from the soil and grass as the wall used to terminate right at the grass.




This post has been edited by kimberlycun: Oct 10 2024, 11:54 AM

The house was unoccupied for 10 years so could be it. From the outside (picture updated in OP), wall looks ok? Just wondering if there's still fresh leakage or from years of seepage.

Not exactly. That's why I'm under the impression it's the unknown solution the contractor used. I could be wrong of course.

Thanks for the suggestion will ask my contractor if this was done.

I'm just stumped coz where the stains are, are supposedly treated with water proofing 😣

You are right, I think due to the age of the house the ground water has come up or something. After some reading we have figured it's an issue called "rising damp" and it's quite a complex thing to solve. Been contacting multiple local leak/waterproofing "experts" but it's an exercise in futility. Hope to find an actual expert that can go with chemical solution rather than a renovation route, as we have just come out of a fully fledged reno. It's obviously very frustrating that this wasn't dealt with more thoroughly during the renovation, and the contractor only painted some dodgy waterproofing solution to the wall as "a favour" to me.

Well if anybody knows any contact that understands Rising Damp please send them my way thank you.