How Many Coats of Finish Do I Use for Hardwood Floors?

Multitude of Choices

• Old-fashioned varnishes are oil-based and leave a durable finish that warms in color over time. They can take several days to apply because of their slow drying time. Also slow-drying but durable, post-World War II oil-based urethane or polyurethane sealers yellow, resulting in a warm glow over time. Nowadays, water-based sealers provide even greater durability with fast drying times and no color change. Three or more coats can be put down in a single afternoon. Penetrating oils and shellac have a mellow shine and are easy to apply, but are not as durable as other products.

A Good Foundation

• Floors should be clean and sanded to a fine finish. Any residual oil or animal urine stains will show through the finished surface. If you stained the wood, let it dry overnight. The room, floor, ceiling, walls and woodwork should be vacuumed to make them dust-free. A sticky tack cloth, available in the paint aisle of the hardware store, removes fine dust from vacuumed floors. Opened windows and ventilation fans remove vapors and air-borne dust from the room during the project.

Layers of Shine

• Three coats of sealer is usually sufficient for a durable and pretty finish. You can add more coats for a more durable, longer-lasting finish that withstands heavy traffic and the abuse of children and pets. Gloss sealers are more durable than satin sealers. For a durable satin finish, use two coats of gloss and top it with a coat or two of satin. If you're using water-based polyurethane, a liquid hardener additive makes it even more durable. Evaluate the finish after the third coat dries. If it doesn't have the shine or depth you desire, add another coat or two.

Attention to Detail

• A light sanding with 320 sandpaper or 0000 steel wool after each coat smooths irregularities and removes dust and small insects that got stuck in the finish during drying. Vacuum the dust and wipe the floor with a tack cloth after each sanding. If you're using water-based polyurethane, the first few coats will raise the wood grain. Sand as you would for other products. Water-based polyurethane dries in 45 to 60 minutes, so the job will still move quickly if you need to apply four or five coats. Don't sand the last coat of any sealer.