Repair deteriorating cement on exterior cement foundation

[Handysyl]

I was scraping the foundation of my home to get ready to paint it. When doing so the cement was crumbling off and I noticed a number of places where there are small fist size indents in the exterior wall. Thy are painted as well.The house was built in 1921. I recently bought it.

 

[nealtw]

The paint is likely the problem. Concrete needs to breath as it will wick moisture up from ground and if moisture is held in with paint it will be subject to frost damage.
Can you post some photos?

 

[Handysyl]

I will







try to share 2 photos.

 

[nealtw]

I'm not the expert here but I think it would be better with out paint, repaired and covered with something that looks good that can breath ( stucco or something like that).

 

[Handysyl]

Ok. I will check with a building supply store. I may end up going with paint just ensure it protected throughout the winter. It may end up bring a bigger job.

 

[nealtw]

It wants to be a breathable paint or you could be making it worse. Something like this.
http://www.klaascoatings-northamerica.com/PDFS/Brochure/Sirex.pdf

 

[mudmixer]

Even if it breathes, too many coats can make it a very good vapor barrier and more problems.

Dick

 

[BridgeMan]

Looks to be light surface scaling. Remove all unsound areas and all of the paint, and then give it a good coat or two of Thoroseal. I don't think you'll find it at most big box stores, so you may have to go to a masonry supply place.

P.S. Cement is a fluffy gray powder that comes in bags or bulk. It is one of the ingredients of concrete, which your foundation is made of.

 

[Handysyl]

So what I needed to move forward and prepare the exterior walls for winter. I have prepared the walls including sealant. I used the surface covering recommended and painted. Next year I will. Get a professional. What expertise should I seek?

 

[mudmixer]

Bridgeman -

I agree with the concept of using Thoroseal for many applications even with a latex additive. Quite simply, it is a cementitous coating that bond well and even becomes a part of the concrete and even work reasonably well over the paint-type coating.

With several coats, the timing between the Thoroseal coats is important to achieve a bond between the first coat while it is active and the second coat. Also the mixing procedure is important to allow the mix to "fatten up" before the final water and application over a moist surface.

I have specified it as a coating on dam repairs and architectural repairs of numerous projects.

Dick