How to Properly Varnish Hardwood Floors

Varnished floors block moisture and stains.

Hardwood floors don’t look it, but they are very absorbent, making them vulnerable to moisture and stains. This is why you should always seal them with varnish or polyurethane gloss. The gloss is a clear liquid that dries into a hard shell, allowing the look of the floor to show through while protecting it from moisture and dirt. The gloss has to be applied in layers, and each layer has to be slightly de-glossed before the next one is applied, or it won’t adhere properly.

Things You'll Need

• Hammer
• Nail set
• Broom
• Tackcloths
• Lamb's wool applicator
• 220-grit sandpaper

Instructions

1. Sink raised nail heads on the hardwood floor with your hammer and nail set.

2. Sweep the floor with a broom, then go over it by hand with tackcloths, which are slightly sticky rags that will pick up any residual dust.

3. Open your varnish and gently stir it (never shake the can, as that will cause bubbles). Pour down a skinny "puddle" of varnish across the floorboards in the far corner of the room, making the puddle as long as the lamb's wool applicator is wide (usually about 2 feet).

4. Set the applicator in the puddle of varnish and slowly draw it backward along the floor, with the direction of the boards. Pull it slowly, watching out for the formation of bubbles. Add more varnish as needed. Work in courses. Do the whole floor. Let the varnish dry for about eight hours.

5. Sand the varnish gently by hand with 220-grit sandpaper, using quick, light strokes to dull the surface so the next layer of varnish will stick. Take up the dust with tackcloths.

6. Repeat steps 3 and 4 to lay a second layer of varnish. If a third layer is desired, dull the surface with sandpaper before laying it. Let the final layer set for 48 hours before using the floor.

References

• FlooringKnowledge.com: Refinishing Hardwood