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I have a poured concrete foundation. A portion of my basement is unfinished.

It looks like a white plaster has been sprayed onto the foundation wall inside my house: Close up

I suspect spraying as there are pieces of wood and other things that are close to the wall are covered in what looks like splash back of the same material: Spray

Due to some previous water damage (the source of the problem has been fixed), this material has flaked off from the wall. I have cleaned up the loose bits with a masonry chisle and now wish to restore the wall in these areas to look like the rest.


I have no idea what this material is or how to apply it. I have searched the internet for things like "spackle" or "popcorn" (since it looks like ceiling popcorn) as they relate to basement or foundation walls but everything I turn up is about troweling on parging mix, portland cement, or other masonry products (i.e. the end result is a smooth wall).

My backup plan should I not be able to replace the material is to figure out what it is and determine if I could parge over it.

Any ideas?

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up vote 1 down vote accepted

Two common types of things are sprayed on basement walls.

What I suspect you have there is a white "waterblocking" coating - something like UGL Drylock (not an endorsement, just an example. I prefer waterbase version) UGK drylock It can be brushed or rolled, and a vigorous rolling may well provide the spatter you see. It's also becoming common to see sprayed-on polyurethane foam in basements (it's better put on the outside, but if retrofitting, putting it on the inside doesn't involve excavating all around the building) but that's usually a bit thicker and somewhat yellow (plus it's obviously plastic when you touch it.)

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I don't think it's polyurethane either. It's hard and seems sort of like an enamel. I think you're right about a waterblocking coat or masonry waterproofer. I searched for Drylok and the website for this product says it can be applied using a sprayer and has a PDF detailing the process. – shufler Nov 15 '13 at 19:37

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