Question: I have a concrete porch that’s been painted several times. But the paint bubbles and peels off, leaving a mess. Each of the painters has said that this happens to concrete when you paint it over the winter. I’m not sure that they are telling me the truth. How do I get the porch painted in the correct manner?
Answer: A variety of issues could be at play here. First, you should determine whether moisture is coming up through the concrete from below. Tape a piece of relatively thick, clear plastic, such as a three-inch square cut from a reclosable plastic bag, to an area with no paint. If moisture droplets appear over the next day, you’ll need to strip off all the paint and switch to a coating that resists hydrostatic pressure. Rust-Oleum’s WaterTite-LV Waterproofing Concrete Masonry Paint is one example. Or you can coat the stripped surface with a concrete-resurfacing material, such as Quikrete’s Concrete Resurfacer, which can be tinted.