How to Refinish Hardwood Floors

How to Refinish Hardwood Floors

1. Remove Trim Moldings

   Floor sanding will be easiest and give the best results if you remove the base shoe moldings, or even the entire baseboards, before beginning work. This will allow the edge sander to get very close to the walls.

   Take care when prying off the moldings to avoid cracking them. Some homeowners use this opportunity to install new moldings, which will give the refinished floor an even better appearance.
   

2. Cover Ducts and Doorways

   Use plastic sheeting, secured with painter's tape, to cover doorways and vent ducts. This will prevent sanding dust from traveling throughout your home.
   

3. Clean the Floor

   Completely clean the surface of the floor. It should be swept or vacuumed to thoroughly remove any dust or debris that may be present. A slightly damp mopping, preferably by hand with a cloth rag, may also be useful to get rid of loose particles.
   

4. Make Any Necessary Repairs

   Examine the floor for protruding nails and pound them down using a hammer and nail set. Protruding nails will quickly ruin sanding belts or pads when you begin sanding.

   Damaged or missing flooring boards should be replaced or repaired before you begin sanding.
   

5. Sand the Floor

   Install a 40- or 60-grit sanding belt on an upright drum sander. While wearing protective gear (eye, hearing, breathing), sand the entire floor, moving parallel to the direction of the boards—not across the wood grain. Sand in a series of long passes, overlapping each pass by 2 to 4 inches. Get as close to the walls as possible, but don't touch the baseboards with the tool.

   How you start and stop the sander is crucial. Make sure the drum is raised off the floor when you turn the machine on, then lower it down onto the floor as you begin moving with a long forward stroke. When you reach the far wall, raise the drum before you stop moving the sander. Failure to follow this method can result in dips and severe damage to the floor.

6. Sand the Edges and Corners

   Using a hand sander fitted with 40- or 60-grit sandpaper, sand the edges and corners of the room, up to the baseboards. In corners, you may need to use a paint scraper to remove the last bits of finish.

   Tip

   To sand under radiators, consider renting a specialty sander with a flat sanding head that fits into tight spaces. Or, you can also sand by hand in these areas.

7. Examine the Floor

   Once you have completed sanding the floor using power tools, you can work on any areas that remain, using medium-grade sandpaper. This can also help to smooth out any rough patches that may have occurred during the process. If gouges are present, they can be filled using wood putty, which should be left to dry for at least 24 hours and then sanded with fine-grit sandpaper and wiped clean with a tack cloth.
   

8. Clean the Floor

   The vacuum attachments included in most power sanders will suck up the majority of the dust generated by the refinishing process. However, it is still important to sweep and/or vacuum the room thoroughly before proceeding. Afterward, use a tack cloth to wipe the floors and walls.
   

9. Stain the Wood (If Desired)

   If you wish, the wood can now be stained whatever color you want. A variety of stains and dyes are available, but one easy method is to use a rub-in stain that is applied with clean rags.

   Make sure the stain dries completely (usually overnight) before proceeding to the topcoat application.
   

10. Apply a Topcoat

    The term varnish is often used generically to refer to any topcoat layer, but there are several options to consider:

    • A simple sealer is a thin, protective liquid that goes over hardwood, both seeping into the pores of the material and creating a clear surface coating over its top. It allows the natural color and grain of the wood to shine through, but it also provides the least protection and may need to be reapplied every six to 12 months depending on traffic use.
    • Polyurethane is now the most common topcoat finish for hardwood floors. A clear, almost plastic-like substance, polyurethane is applied with a standard paintbrush and is available in a variety of finishes, from matte to glossy. Its purpose is to create a clear, protective layer over the top of the wood that resists stains and scratches. 
    • Traditional varnish is similar to polyurethane, except that it has a more dramatic effect on the wood, darkening it noticeably. The advantage of this substance is that it is thinner, so spot repairs can be more easily made when future damage occurs.

    Whatever finish you choose, make sure to follow label directions exactly, especially when it comes to safety measures and drying time. With many topcoats, you can expect to apply at least two coats, allowing each coat to dry overnight before proceeding to the next.

    Tip

    Polyurethane finishes are available in both water-based and oil-based formulations. Water-based poly is easier to use and dries quicker, but it has a tendency to show imperfections. Oil-based poly is slow-drying and smelly, but this slow-drying characteristic allows the finish to achieve a very smooth, elegant look.

11. Replace the Moldings

    The final step is to install the base shoe or other moldings along the walls, covering the edge of the newly finished flooring. These moldings are easy to tack into place with a brad nailer.

Tips for Refinishing Hardwood Floors

• Though it's recommended to remove baseboards to refinish hardwood floors, you can instead keep them in place and protect them from the sander with foam held on by masking tape. 
• Sweep and vacuum the flooring to remove dust and debris between sanding with different grades of grit.
• You can stay in your house while your floors are being refinished, depending on where the floors are located. If the floors are in the main living space, you might decide to stay out of your home for two days after the floors are done to avoid the fumes.
• Put felt pads under the feet of your furniture as you move pieces back in place to prevent them from scratching the newly refinished floor.
  

When to Call a Professional

If you perform the work yourself, then you will have to rent a walk-behind, solid-wood sanding machine as well as hand sanding tools, which will cost roughly $200 per day. And it's easy to make mistakes that can irreparably damage the wood flooring surface. More than one homeowner has eagerly set out to find the cheapest way to refinish a hardwood floor, only to end up spending a lot more to replace the floor entirely.

Refinishing hardwood floors is no easy task. If you're uncertain of your skills, it may be best to leave it to a professional hardwood floor refinishing service. A professional will charge $3 to $8 per square foot to refinish a hardwood floor, depending on the size of the job. The professional process includes sanding, plus the application of two or more layers of surface finish. The process will generally require three to five days, including cleanup.