Basement floor paint problem?

Question

I recently bought a 100+ year old house. I began painting my basement and the walls look great but my floor has been nothing but trouble. It is cement but portions seemed to have been patched at different times.

I swept the floor many times before beginning to paint. I didn't do anymore prep because the walls painted well without extensive washing and I didn't see any grease stains or moisture.

I painted two coats and after drying the paint began to bubble. While scraping up the bubbling a layer of the cement underneath seem to come up with the paint in some areas.

This just seems to keep getting worse. How do I know I have taken up all of this crumbly top coat of cement? And once I have should I cover the cement underneath?

Answer 1

It might not show, but you have a moisture problem. Your question here  is should I coat or should I cover. The answer is cover because regardless of how clean you get your cement floor or what kind of additive or if it's oil based or epoxy or latex, you'll still have a moisture vapor coming up from below. Cover it and enjoy your basement.

Answer 2

That's one bitchin' problem.  What I'd do is read up the info on the Flood company's site on EB (emulsabond) and Penetrol, both of which I have used in tricky situations and found to be double-excellent.  No- they aren't paying me to say this!  EB mixes with water-based paints and grabs into hard to hold surfaces e.g. porous, old whitewash etc.  Penetrol does the same with rusty surfaces without the need to scrape back to clean steel and use rustproofer - I've found it better than that.  Have also used it in paint around windows and it was the devil's own job to scrape paint off the glass when dry!  Go to their site and look right into every section of - probably for you - EB instructions and uses, not just the first brief outline of its use.  If you have a good paint store in your area ask them too.  Most paint sellers are just shop staff though and only know what the latest company rep told them :-}