3 years ago I repainted a concrete block building. I power washed and then used acid and washed it. The paint is peeling at the mortar joints. There is a metal cap that covers the block. I recaulked the the laps in the metal cap thinking that’s where the water was getting through, but the paint is still peeling and the building looks bad. Can you give me some insight?
Were this my building to maintain, I would handle this way.
* First, pressure wash the block with heavy concentration on the mortar joints.
* Second, prime the joints with a masonry conditioner/primer. Most paint dealers will have this type product available. Sherwin-Williams' is a "Lok-Tite" product made specifically to control this type issue. Apply the conditioner/primer and then finish.
If the problem were a moisture problem, I feel it would not be limited to the mortar joints.