Mopping hardwood floors with water is a mistake. Don't let yourself be caught doing something stupid. Wood and water just don't mix. When they get together, all sorts of bad stuff happens. Boards crack, warp and come loose. So how do you clean a hardwood floor you ask. First, there are two types and two different ways to clean them. Custom-finished floors should be cleaned with a damp sponge or mop-moistened with warm water that is 5 percent vinegar. Wring your sponge or mop out twice to be sure you don't leave puddles to seep into cracks. For today's prefinished hardwood floors, clean and wax with products offered or recommended by the manufacturer to preserve both the life of the floor and the warranty. If it's not prefinished hardwood, use the same 5-percent-vinegar solution, and moist-mop treatment mentioned earlier. In either case never just slosh water on a hardwood floor. Wood and water don't mix. And that's the On The House tip for today.