The varnished truth: got a weary-looking wood floor?(special section - flooring)(Buyers Guide)

Refinishing an existing wood floor is your easiest option if only its surface is worn. At about 20 cents per square foot for the varnish, it's also far less expensive than the $4 to $8 per square foot you'll pay for new wood flooring. But whether you handle the job yourself or hire a pro, expect days of disruption, sanding, dust, and fumes. You also face significant cost and convenience differences between varnishes--key reasons why choosing the right one for your needs is critical no matter who puts it on.

We tested 11 water-based and 12 solvent-based varnishes, the two major types, focusing on products aimed at do-it-your selfers. Also known as oil-based varnishes, solvent-based products use a solvent such as mineral spirits to deliver the resins that eventually form the finish. Water-based products hold their resins within an emulsion. That difference affects how quickly each type dries, how many coats it requires, and how it will look on your floor.

All the varnishes we tested contain polyurethane--a tough resin designed to resist surface wear and provide a no-wax finish that's easy to clean using a damp mop. You can also buy solvent-based, "moisture-cure" varnishes that promise an even tougher finish, though we don't recommend them for do-it-yourselfers.

Suppose your wood-floor finish is worn but not worn through to the wood. You can also choose a varnish that goes on without sanding (see "Remedy for Less-Worn Floors," page 42). Applying it is hardly a cakewalk, however.

HOW TOUGH?

Spills. We subjected both types of varnish to vodka, wine, coffee, cola, and other liquids infamous for damaging floor finishes. We also exposed all of these products to common surface cleaners such as liquid detergent, ammonia, and white vinegar. While most of them held up well, only one--the water-based Flecto Varathane Waterborne Gloss--came away unscathed by both drinks and cleaners.

Sunlight. Bright, sunny rooms are one place where water-based varnishes have an edge. All those we tested withstood intense exposure to ultraviolet (UV) light without changing color. By comparison, all of the solvent-based products we tested darkened.