Failing concrete block and paint.

Questions & AnswersCategory: Painting Brick, Stucco and MasonryFailing concrete block and paint.
Mike asked 10 years ago

After the last paint job on our block building, the paint is failing and the mortar and block is too. One contractor suggested moisture from inside of heated office areas was causing outside to fail. Inside is sheetrock and has never been an issue since 1978

2 Answers
Anonymous answered.

Paint peels when moisture gets under the film and causes pressure. The moisture has to be coming from somewhere but the paint didn't cause the failure of the block, excessive trapped moisture caused the failure. This type of failure, crumbly block and mortar, takes time to develop. Look at all areas that moisture can get in; cracked caulking around windows and doors, roof flashing, etc.

JT Creations, LLC answered.

I would have to agree with the moisture suggestion. Primary cause of paint failure is moisture. On block buildings moisture is easily passed through. I would check the roof area to see if that is where you are getting moisture inside the block.