# Mold on Plaster Wall



## mds120 (Dec 15, 2008)

We have a problem with knockdown texture coming off a plaster wall.

About 2 years ago we wire-brushed a plaster wall and removed any loose material. We textured the wall with knockdown and then it was painted. 

As a result of a roof leak, which has been repaired, moisture caused the texture to fail in areas. 

The moisture came out of the plaster underneath the texture and paint, causing the surface to bubble. As you can see in the photo there is mold.

We also found visible traces of surface mold on the plaster when we removed the loose texture and paint.

We believe the mold is on the surface and can easily be removed, killed and sealed. However, I'm wondering it we should take a chunk out and see if the plaster is laced with mold as well.

I would appreciate your feedback on if it is possible to apply something to the wall then texture it again. I found it strange that the water/moisture has apparently run down between the outside brick wall and through the plaster before being trapped under the texture and paint. The customer says he never saw any sign of water on the walls painted surface.

I'm also worried that there is lingering moisture in the plaster wall that could cause our texture to fail again. The texture in areas unaffected by moisture is very solid on the wall.

Thanks,


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## Big Shoe (Jun 16, 2008)

Not an expert on plaster walls, but if it was drywall I'd remove the wall and hang new board. Or at least cut a hole in the wall to see what's going on in there. 

From the looks of that picture I would think the framing in the wall could be damaged from moisture. Slow leaks cause the most damage and that is a large area of mold.

I never dealt with mold on plaster, I'd like to see how this turns out.

Shellac based primers hide water stains well if that's the route your going in,but I don't recomend it.


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## Frankawitz (Jun 17, 2006)

Well if you could post a better picture it would help, if that's mold and you said it's from a roof leak the ceiling would be showing signs of mold and paint peeling, when plaster gets wet it will cause the paint to bubble, But if this is mold then it would be coming in thru the back side of the wall, which you will need to remove it, then install new rock lath base coat and then skim coat it.
there is no way your going to get the mold out with chemicals.:thumbsup:


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## CilasConcrete (Aug 12, 2010)

*try this*



mds120 said:


> We have a problem with knockdown texture coming off a plaster wall
> 
> I'm also worried that there is lingering moisture in the plaster wall that could cause our texture to fail again. The texture in areas unaffected by moisture is very solid on the wall.
> 
> Thanks,


Did you try getting an actual mold tester guy?


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## Resta (Feb 11, 2009)

Years ago, when people use lime paint/white wash, they were adding formaldehyde in the paint. Remember school years, we kept frogs in that formalin. 
Many moons ago, we painted our apartment, closed windows and doors and leave for two weeks vacations. When come back we found all walls with mold. It was real plaster walls...brick, brown coat and etc...We washed with formaldehyde, let it dray, add formaldehyde in the paint ant painted. Later we lived in that apartment for 15 years and mold never shows.


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## Paulie (Feb 11, 2009)

Resta said:


> ...We washed with formaldehyde, let it dray, add formaldehyde in the paint ant painted.
> 
> 
> Where the heck do you get formaldehyde?


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## boman47k (Oct 13, 2006)

> Where the heck do you get formaldehyde?


Know any undertakers? :shutup:

Didn't they use it? Maybe they still use it for embalming.


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## Frankawitz (Jun 17, 2006)

So MDS120 What happened did you fix it or what did they end up doing?
Or are you going to just leave us out there hanging:whistling


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## Resta (Feb 11, 2009)

That time we worked at 17th century monastery, with the UNESCO and ICOM standards and recommendations. It was the chemical whichever we treated the ancient fresco and limestone from mildew ... so I just borrowed a handful of crystals ....
Google where to buy it...


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## Leafan (Aug 10, 2010)

If this were me. I would highly recommend removal of any moldy plaster. Inspect framing for rot. If any replace it. Then spray with Concrobium to kill any remnants. Then new drywall. 

Note. Ensure the roof leak is repaired first or your wasting your time and his money. 

Just my opinion.


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