mold on patched basement walls

Evening all,

I have an issue I am looking to fix. I have a house built in the 30's that at one time had a water issue. Years ago they put in a bee dry system, patched the exterior basement cinder blocks where erosion occurred and went over the walls with mold free paint. This has corrected any water in the basment however over time the areas that were patched on the walls are again starting to crumble and those areas of the walls are now getting yellow/brown mold over those weak spots.

I would like to take out all the old patching, refill the spots and repaint over the walls with a newer mold proof paint. What is the best patching material to fill in the spots and best paint to stop this from happening any time soon again. Any ideas are appreciated.

Thanks,

Justin

 

Yellow - Brown mold?? are you sure this is not effervescence??

 

I guess I am not sure, however, it is yellow in color and when I spray it with a bleach solution, it turns white and I can scub it off.

 

When it is dry can you rub your finger across it and it fall of the wall?

 

no, not very easily. It needs to be scrubbed to be removed. In some areas it's just a yellowsh stain, in other areas, there is growth that can be felt, somewhat hard.

 

I am still thinking that that this still might not be mold. If it is cleaning it will be fine. Let it dry then you can paint.

 

can be something else, rather than mold.

It can be a substance we all ocher. It is actually a bacteria, or better, a colony of bacteria that feeds on iron.

That indicates the presence of iron in the terrain around your house, which is mixed with the water that seeps through the foundation and builds up up on wall and surfaces. You might notice rust stains in the walls before you notice the bacterial growth.

This growth is a brown-orange-yellowish type of scum and can be very bad news because it builds up very quickly and clogs the drainage system, weakening it or rendering it useless.

(Probably the reason why you see the patches crumbling). The system is not 100% functional, and the ground outside is getting saturated with water, and it is pressing against the wall, causing the patches to crumble.

So I'd say that, first of all, the drainage system needs to be flushed. Hopefully the contractor who did the job installed a drainage system that allows it. Because you will have to flush it consistently over the years.

Waterproof paint or coating will not be able to keep the water out when you have an over saturated backfill. It is not made to withstand hydrostatic pressure. It will at some point, crumble and peel off as it is now.

Your best alternative would probably be lining the walls with a vapor barrier or waterproof wall panels.

In every case, I recommend you get the waterproofing company to service the drain system and it would be a good idea to research new solutions for the wall rather than do over the patching and painting that already failed once.

 

I thought it would be helpful to post an image of the stain that I am talking about. Here is a spot on my wall. It is dark yellow now, if I spray it with bleach water it turns white and I can scub it off. However, I feel it will eventually return as the wall under it is the patch that is crumbling and more damp that the rest of the wall.

 

100% effervescence! Just brush it off