Water and other liquids can penetrate deep into the grain of hardwood floors, leaving dark stains that are sometimes impossible to remove by sanding. Instead, try bleaching the wood with oxalic acid, which is available in crystal form at home centers or paint stores.
How to remove stains from hardwood floors:
1. Remove the floor’s finish by sanding the stained area.
2. In a disposable cup, dissolve the recommended amount of oxalic acid crystals in water.
3. Wearing rubber gloves pour the mixture over the stained area, taking care to cover only the darkened wood.
4. Let the liquid stand for 1 hour. Repeat the application, if necessary.
5. Wash the area with a solution of 2 tablespoons borax in 1 pint of water to neutralize the acid.
6. Rinse with water, and let the wood dry.
7. Sand the area smooth.
8. Apply several coats of wood stain until the bleached area matches the finish of the surrounding floor.
Wood expands and shrinks according to weather conditions— especially humidity—causing floorboards to rub against each other and against the nails holding them in place, and thus to squeak. It pays to check, however, whether the source of persistent squeaky boards is more than a change in weather. Sometimes shifting or squeaking boards can indicate a bigger problem, like leaking pipes or drains. Be sure to check under the floor to make sure it is free from water damage or rot.
Although there are little tricks to get rid of those squeaks, sanding and refinishing the floor is not one of them, so don’t let any professional talk you into something you don’t need and that won’t fix the problem. Little tricks are good, but to truly fix the problem, you will need to uproot your flooring and repair what’s going on underneath it.
One trick, for a temporary fix, is to put some baby powder between the boards that: squeak. Step on the boards in a bouncing action to allow the powder to seep into the joints.