We have a concrete-block retaining wall which is unsealed on the earth side. No matter what we put on the face side, whether sealer or paint, it falls off. What will stop the paint finish from flaking? Harriett Sallee Kamuela, Hawaii
A. Wire-brush all loose material from the exposed masonry face. Then removed any alkaline efflorescence with a mixture of 1 (or more) to 10 of muriatic acid and water. Don't let the acid mixture get on either skin or clothes. Rinse with clear water.
Apply a product, such as Sealwall, to the block face. Be sure to follow exactly the manufacturer's directions.
You can obtain Sealwall from a local supply house or directly from the company at $36300 Lakeland Boulevard, Eastlake, colored vinyl or acrylic paint you choose.
And that's all there is to it.