Spots on wall

I have some brown spots forming on our exterior walls in one of our rooms. They started about 2 years ago when we got our walls insulated with AirKrete.

Here are the pictures:

Picture 1
Picture 2
Picture 3 (Brighter)
Picture 4 (probably the best)

I can rub the spots and they don't come off, and we tried cleaning with just water and that didn't take it off. I'm not sure what it is, how to clean it, and how to keep it from happening again. Any ideas?

 

Certainly looks like moisture. I have not used the AirKrete, but it does go in wet. But you would think it would dry over time, less than two years. If it is an issue with the AirKrete, you should be able to get them to take care of it, even after some time. If they have a problem with the product or the installation, they should want to know it.

I would start with the contractor who installed it and if no results, move on to the product mfg. Going back to the contractor isn't complaining, it is giving them a chance to defend their product by making things right.

There are stain blocking paints and primers, but you need to check for moisture before you do anything. A moisture meter of Infrared Camera would work.

Bud

 

It sure looks like a water stain. You will need a solvent based primer to seal the stain. Latex based stain hiding primers do a poor job of sealing stains.

I don't know anything about AirKrete. If the moisture is gone, prime and paint is the fix. Water stains won't wash off.

 

I'll try to call the contractor on Monday and see what they say.. I was rubbing some of the spots and some of them did have a residue that came off. Should I try scrubbing with something like TSP or a bleach solution?

They didn't start showing up until the winter after the AirKrete was installed, and we're getting more this winter. At first I thought we just got condensation in a corner where my wife had her stuffed animals stored, but now they're showing up in the middle of the wall where nothing was contacting it. Would a stain have taken that long to work through the walls?

It's plaster and lathe wall if that matters.

All the places where I've found AirKrete, it's dry as a bone, so I would certainly think it's all dry by now.

 

AirKrete is a foam composition of cement. If there were a void or high density spot in those areas, it could be related to the staining. I would let the contractor take a look before I tried to cover or remove them. A look with an infrared camera would be telling.

Bud

 

Well, they looked with the infrared, and we we didn't see anything with those particular spots. He agrees they look like water spots, but the guy that came out has never seen anything like them.

He took pictures with the infrared and a digital camera to have several other people review them and let me know what to do.

He recommended reducing humidity in the house (even though it's not high) and see see if that prevents the formation of the spots.

His other theory is that it is a water stain from the installation that for some reason worked it way through a defect in the plaster and that covering with a killz type product would resolve the issue.

So I'm going to play a wait and see game. Need to turn down my humidifier, but my RH is only 30% most of the time.

 

Have him provide you with those IR pictures so you have a reference years down the road. If not temperature differences were detected, then no moisture is present and there are most likely no voids in the insulation. Thus I tend to agree with the water stain from the original installation working it's way through.

30% should be ok, less than that and your cat will move out or stick to the furniture.

Bud

 

Is there any consistency to where on the wall these spots are? Like a regular height off the floor? Any relationship to the distance from windows? On all the exterior walls? Only one side?

This is intriguing.

 

The spots are only on exterior walls, but other than that they seem to be random. Our bedroom is the main one, but we have one spot on my daughter's room. My son's bedroom is fine. All of our downstairs walls are fine, but they were re-plastered so they have an extra layer.

 

Maybe it's an issue from the AirKrete installation. You might try coating those spots with an oil base or shellac primer and touching up with paint. If it was caused by the installation, that will fix it. If the spots return then there is a current moisture issue.

 

Will need to wait for warmer weather to use a solvent based primer. Sounds like a plan though.