A.Jay Meunier responds: Either paint or sealer will slow or prevent road salt damage to a concrete slab. Sealers are typically easier to apply, because they require less surface preparation before application. We have had great success in harsh environments with a tung-oil concrete sealer called Waterlox Cement Stain 2000 (800/321-0377; www.waterlox.com). After preparing the concrete with an acid wash, one or two coats of stain are applied. We have used this product in auto body shops, and it holds up well. The sealer is highly resistant to salts, acids, chemicals, and oils. A less expensive sealer like Thompson’s Water Seal will work but will require reapplication much more frequently.