Tips and Tricks for Refinishing a Hardwood Floor

by on December 30, 2012Karie Fay

refinishing a wood floorWhether you simply need to refinish your hardwood flooring, or you have discovered an old hardwood floor underneath years-old carpet, you can restore the look and bring back the beauty of the floor when it was new. Don’t go running for a sander and varnish just yet, however. Kind of like customers at a hair salon, one floor may require a different cut and color than the next. Choose the finish removal appropriate for your floor and the finish that matches the wood. With a little preparation, you’ll soon have a refinished wood floor that everyone will rave about.

Assessing the Condition of Your Hardwood Floor

Before you do anything, you need to determine the condition of your wood flooring and the finish as well. Knowing the age and thickness of the original hardwood floorboards, how many times the floor has been sanded, and the finishing products previously applied helps you decide how the floor should be stripped and how it should be finished. Making a mistake can be costly and damaging, so if you aren’t sure, a little investigation is in order. At the same time, make note of problem areas that may require a little extra prep work before refinishing the wood.

Keep in mind that refinishing a hardwood floor is a lot of work and time-consuming. Hiring a refinisher may be a better option for you. However, even if you choose to let a pro handle your floors, you can significantly lower the cost by assessing your floor yourself and performing the prep work so the pro can get right to work.

  • Is there anything stuck to the floor, such as remnants of old flooring and adhesives? Don’t attack such spots with a sander – it will be rough on the sander and sandpaper and may result in uneven sanding. Remove old floor coverings manually and use specially designed chemical strippers, as appropriate, to remove adhesives.
  • Are there nails sticking out of the wood boards? Are there boards missing or any significant cracks in the wood flooring? Missing boards need replacement – consult a professional if you are uncertain how the floor was originally installed and how to do it yourself. Cracks will fill easily with a little wood putty, spread over the crack with a large spatula and then sanded with the floor once cured. Nails need to be well below the floor surface. Run your hands across the floor if you are uncertain. Even the slightest protrusion will cause problems. Countersink nails slightly with a hammer and nail punch. Spread wood putty across nail holes to hide their presence if desired.
  • Can you see stains soaked into the flooring? Are there deep scratches and dents? While wood putty can fix many blemishes, some may require replacement of the floorboard involved. Deep stains may require a thorough sanding to remove, and, even then, traces may remain. Some refinishers will even try oxalic acid, but it bleaches the wood at the same time as it removes the stain. A good finish is meant to prevent this damage, but if you don’t know the floor’s history, you can’t be sure the floor was kept protected. Simply covering a stain with a new finish generally doesn’t work well, as the stained area will receive color and finish products differently than bare wood. Consult a professional with help in replacing wood boards and treating deep or significant stains and other floor finish concerns or problems.
  • Is the current finish fairly sound? Perform a water test to judge the condition. Simply drop a spoonful of water on the floor and see if it soaks in or beads up. If the water simply pools or soaks in slowly, the current finish may not need as intensive of a refinishing treatment. If the water soaks in quickly, the floor needs to be sanded down to the wood.
  • What finish was previously applied to the wood? Wood finishes are not interchangeable – once you use one finish product, unless you sand the floor completely down to the wood, you need to use the same product again. Except, that is, for wax finishes. Use a solvent to determine the type of finish:

Wipe a small area with a cloth dipped in mineral spirits or paint thinner. If the finish comes off on the cloth, a yellow or brown residue, a paste wax covers the wood. Alternatively, drop a spoonful of water on the area and use steel wool to see if the finish comes up as a gummy residue, which looks grayish on the steel wool. Wax is often found on older wood floors – pre-1930 – when a penetrating oil like tung oil was applied, then covered with wax for shine. While wax soon declined as new finishes became popular, it is still an option to wax new wood floors.

Mix a small amount of water and ammonia and add a little dish soap. Drop a spoonful on the floor and let it set a minute. If a hazy, white discoloration results, the floor has an acrylic wax finish. Use rubbing alcohol, purchased at the supermarket, to see if it softens the finish. If the floor becomes gummy or sticky, the finish is shellac.

Lacquer thinner will soften both lacquer and water-based finishes. If it works, follow with a drop or two of either toluene or xylene – available in the paint section of your local hardware store – to see if that softens the finish as well. If it does, you know you have a water-based coating. If it doesn’t, the finish is lacquer.

If none of the solvents work, a reactive finish such as polyurethane or varnish is the likely finish. The exact type doesn’t matter – any reactive finish is compatible.

  • How thick are the remaining wood floorboards? There are only so many times a floor can be sanded, realistically. Very old hardwood floors may be several inches thick, but newer wood floors tend to be much thinner. If your floor is less than about ¾ inch thick, sanding down the floor and completely refinishing may not be the way to go. Look along the room edges, at transitional floor trim or along floor vents, to measure the thickness. If your floor proves thin, consider another refinish option or even replacing the flooring. Consult a professional for expert advice and assistance.
  • Should you simply replace the flooring? Choosing total floor replacement is a last resort for cases of excessively thin wood boards or severe stains. Even if a board or two is damaged and needs replacement, it’s much cheaper to hire an installer to replace a couple of boards, if you choose not to do it yourself, than to totally replace the entire floor.

Choosing a Refinishing Method

Once you’ve examined your floor and considered the condition of the current finish, how thick the wood and what areas may cause problems, you’ll have a better idea of your floor’s needs. Before refinishing the floor, countersink nails, fill cracks and replace boards to prepare for the job ahead. Clear the room of as many furnishings as possible to make the work easier. Take the time to remove baseboard moldings or anything you may bump against on the wall. Hang plastic over doors and tape across vents and electrical outlets – any sanding creates a lot of dust, and you don’t want it spreading through your house. Finally, choose a refinishing method depending on the level of refinishing your floor condition demands.

  • If the floor has a wax coating and it looks scratched, wet the scratches to see the reaction. If the scratch seems to disappear, try buffing the floor with additional wax for a simple refinishing.
  • Sometimes, if you catch the floor soon enough, you can simply re-coat the wood after removing the existing non-wax finish, a process often referred to as screening or scratch-sanding. This requires a buffing machine or floor polisher, fit with special clog-resistant sanding disks of different grits. Easier to use than drum sanders commonly used for complete finish stripping, screening abrades and removes the finish without sanding the wood. A belt sander is necessary around the edges. Afterward, all traces of finish and dust are lifted with a cloth dampened in mineral spirits. A similar finish product – typically varnish or polyurethane – is then applied. Screening works best on worn finishes where the wood isn’t stained or damaged, and never on wax finishes.
  • Strip, rather than sand, with chemicals. For most finishes, the same solvent that softened it will also remove the finish with a little work and patience. After that, it’s simply a matter of applying a new, compatible finish according to the product instructions. The exception is a wax finish. The problem with wax is it’s very difficult to completely remove. You may think it’s gone, but it soaks into cracks and between boards and then, when you apply a new finish, surprise! The finish doesn’t cure (harden) and all your work is for nothing. If you’re determined to refinish a wax floor with a new finish, the floor must be minutely scrubbed (think toothbrushes and scouring pads) with an appropriate stripper and then sanded if at all possible. For best results, hire a refinishing professional to chemically strip the wax for you.
  • For the most intensive refinishing job of all, you’ll need heavy-duty equipment – a buffer, a drum sander, an orbital sander, a floor edger, a Shop-Vac, lots of sandpaper (did we mention lots?) and various tools such as paintbrushes, rags, rollers and such as needed for stains and finishes. The big sanders can be rented fairly inexpensively, by the day. The ability to handle them may not be quite so easy. The first in the process, the drum sander, is loud and. Start it while tilted, not in touch with the floor, then slowly lower it. Practice in unnoticeable areas and keep it moving at all times. It sands very aggressively. Both the drum sander and the orbital, used at the edges, begin with 20- to 60-grit sandpaper and work up, one grade at a time, to 120. The floors must be thoroughly cleaned between each round to avoid digging up the surface. After the sanding is finished, all it takes is color, if desired, and a finish to seal the deal. Always follow the product instructions for best results.

It’s (Almost) All About the Finishing Product

At this point, if you’ve stripped your finish and sanded your wood, you have almost endless possibilities for finishes. A varnish, for instance, may be used alone in clear or colored formulas. A stain topped with polyurethane is another popular choice, or an old-fashioned linseed or tung oil covered with wax may suit your preferences. Research your options before deciding what to use – a wood floor lasts nearly forever, and you don’t want to have to do a complete refinishing anytime soon. With care put into refinishing your floor, and a little time and attention put into taking care of the new finish, you won’t have to.

{ 10 comments… read them below or add one }

Cristie September 18, 2014 at 9:30 am

Hi Karie,
We recently moved into an old farmhouse. We were planning to replace the old carpet with new; but when we removed the carpet and laminate we found original wood floor underneath. My husband sanded them down and we filled the cracks with wood filler and then topped it off with a sawdust and wood glue mix. I tried to sand down the left over wood filler along the crack lines but didn’t get it all off. Then I placed polyurethane over it. Now the floor has this grayish discoloration along the cracks of each board. I am afraid that I am going to have to start over with a sander. Is there any other way to fix my mess?
Thanks for your help.

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MaryAnn Morris August 21, 2014 at 12:27 pm

I refinished an old wood floor last year, sanded it until smooth (probably 90 years old) than I put tung oil, seven coats on it. I like it, but since then I did another floor
using stain and Poly, I like this floor so much better, can I now sand the tung oil down, stain and poly this floor? The last floor was hard to do because I had to remove layers of varnish, hand sand and then put the conditioner on it and then the stain and then 3 coats of poly (I am 74 years old, female) but I am not afraid of work, so I will do the other floor if I can. Please advise

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Karie Fay September 8, 2014 at 8:51 pm

Hi MaryAnn!
Wow – I am impressed you do this yourself! How awesome!
I wouldn’t be scared to try it at all. Do you have wax on the tung? Either way, IF you can sand the tung away and get into wood you should be ok.
Good Luck!
Karie

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Jim Rixey April 21, 2014 at 5:29 pm

Think I already know the answer to this question. If I’m refinishing the whole first floor. Is there a way to do one room at a time instead of moving all of the furniture out of the house? Thanks

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Karie Fay April 24, 2014 at 5:14 pm

Hi Jim,

Yes. Considering the dry time needed before you walk on the floor or set objects on it, I would suggest moving the furniture out of a room or two at a time and do your first floor in stages. It means you have to deal with the mess and hassle longer, but it will allow you to continue living in your house while you do it.

Good luck!
Karie Fay

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wendy October 22, 2013 at 4:03 am

hi I have just sanded original floor boards and am now slightly confused about what finish to use, I would like to wax rather than varnish, do you have any tips or recommendations on what to use, many thanx

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Karie Fay October 26, 2013 at 5:06 pm

Hi Wendy,

Thanks for writing. When it comes to what you would like to use on your wood floor, it really is about preference. Each finish product has benefits and drawbacks, so it’s difficult to say what’s “best.”

You mention that you would like to use wax. I am curious why — is it because you think it protects more than other finishes? Fact of the matter is varnish and polyurethane are actually harder than wax and protect the wood from moisture and damage better. However they can be more difficult to apply as well, along with other disadvantages.

More people are turning back to the old-fashioned wax finishes. The great thing about wax is with heat from friction and use, it melts slightly, helping to fill in scratches and blemishes. The bad thing, as mentioned in my article, is if you want to refinish your floor, you have to make sure it’s TOTALLY removed before you can add any other finish.

To use a wax finish, I would personally likely go with either a Tung oil finish and top with either liquid or paste wax, or I would use a newer product called “hardwax oil” which combines oils with waxes and replaces both.

You could use other types of oils, but many like Tung oil and it has wonderful qualities such as no VOCs, totally “Green,” and non-toxic. Likewise, some use shellac (another natural product, made from the Lac bug) and wax over it. From your question, however, I am thinking you would be most satisfied with an oil and wax finish.

One key point — if you use oil, make sure it is completely dry and cured before waxing. If wax is applied too soon, you will end up with a sticky mess.

Hope this helps,
Karie Fay

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Wayne Pro September 17, 2013 at 12:16 pm

Great post. Refinishing your floors is so hard for DIYers but can be a big big accomplishment.

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Feinmann January 14, 2013 at 3:24 pm

Refinishing your hardwood floors can add a whole new look to your home and increase it’s curb appeal. Many times, houses have finished hardwood floors that have been covered by carpeting. Tearing out the old carpet and refinishing is an inexpensive way to update either a single room or the whole house.

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Natalie Turner January 3, 2013 at 9:28 am

Hi Karie,

Great post here! Some important points made, especially about ensuring you use the correct methods when it comes to refurnishing; often enough you’d see perfectly okay floors damaged which can be quite costly!

Hope you had a great xmas!

Natalie x

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