Wood floor refinishing is a big part of living in an old house. Your wood floors take a lot of abuse over decades or centuries of foot traffic, sliding furniture legs, scraping Tonka trucks, and everything else that happens in your house on a daily basis. They need to be cared for certainly, but sometimes the wear and tear is just too much and the floors need a refinishing.
Refinishing wood floors is an incredibly invasive process that requires you to move everything out of the room for a number of days, which can be a major annoyance. If at all possible I recommend that if they are in need of refinishing, you have the work done when you first purchase the home before you move in. That saves a ton of headaches, so give that some serious thought before the movers arrive.
Wood floors can be made to last for centuries if cared for properly so before you think about covering them up because they look too battered and worn give this old post a read and let me know if it changes your mind a bit.
In this post, I’ll walk you through two different options for refinishing your wood floors. The first is your standard sand and refinish that has been in practice for well over a hundred years, and the second is a relatively unknown but extremely valuable method my good friend Bob Yapp calls Passive Floor Refinishing. If you have an old house you definitely don’t want to miss this process because it can be a game changer!
Wood floors only have so many sandings in them before you sand away too much for the floor to remain stable. A proper refinishing will likely remove around 1/16″ to 1/8″ of wood along with the finish depending on the condition of the floors and the skills of your refinisher. If you don’t have that much wood to spare then the only option you’re left with is Passive Floor Refinishing.
Standard Wood Floor Refinishing
For a long time the process for refinishing wood floors has remained unchanged and that’s mainly because the process works so well. Much like we haven’t been able to build a better mouse trap, the process for sanding the old finish off a wood floor and preparing it for new finish has been boiled down to its most essential and effective steps which I’ll outline below. The process for refinishing wood floors in this section is not incredibly DIY friendly. These tools are difficult to handle and it’s easy to gouge wood floors so be careful if you go this route on your own.
If you want to give it a go just be careful because getting a flawlessly smooth floor with sanding is a serious challenge for a novice. If you want to do the work yourself I would think more about the Passive Floor Refinishing below.
When I first started my business in 2010 the majority of my work was in repairing and refinishing wood floors so this is a topic that is near and dear to my heart. In fact, it was the topic I worked so hard to refine my skills at that Fine Homebuilding and ProjectHouse did featured articles on my techniques for invisible repairs to wood floors. That’s not to brag, but to let you know that this is a subject I’m well acquainted with. Let’s get into the details!
Sanding Wood Floors
After you’ve removed all the furniture from the room the first thing you need to do is sand the old finish off your floors. There are three tools that get this job done post haste. First is the drum sander which is a big, bulky power tool that does the bulk of the removal from the floors. You’ll do multiple passes across your floors with different grit abrasives, the first of which is usually across the grain at a 45 degree angle.
Once the drum sander has done its work you’ll be left with a few inches of flooring near the walls that the drum can’t reach and for that you’ll switch to an edger. The edger is a much smaller sander that may seem easier to deal with but it is a whirling dervish that can easily get away from you and put huge gouges in your floor if you don’t know how to handle it. Think a random orbit sander on massive steroids! The edger can get right up to the baseboards and do almost everything except for inside corners since it is circular.
To get those last few tiny inside corners you’ll need a good old fashioned steel scraper to scrape with the grain to remove the last vestiges of finish and bring it level with the rest of the floors. Having an extremely sharp tool is key here.
What Grit Paper?
Most refinishers use a 3 stage sanding process. I preferred to do one pass in 36-grit followed by another in 60-grit then the final with 80-grit. Keeping the progression close together makes sure to remove the scratches from the preceding grit paper. For floors with heavy adhesive or other build up it may be necessary to start with something like 24-grit paper or in extreme cases 16-grit paper. That means you will likely have to do an additional pass because ending with 60-grit is too rough for a satisfactory final product.
We’ll talk about adding stain and finish in the next section since it is the same whether you are doing standard or passive refinishing. First, lets dive into the passive way of removing finish.
Passive Wood Floor Refinishing
When you want to refinish your floors, but can’t or don’t want to sand them then this is the method for you. Pioneered by Bob Yapp on his PBS show About Your House, passive floor refinishing is a way to chemically remove the finish from your floors in preparation for new finish. Here’s how it works
Apply a non-toxic, non-flammable chemical stripper (Blue Bear Paint & Urethane Stripper, formerly SoyGel) or something similar is a good option) to the floor in manageable sections and let it work its magic. Once the finish has softened, using a floor polisher that you can rent at most home stores and a 100-grit screen go over the area to remove the remaining finish and stripper.
Use a clean cloth to remove the excess stripper and use a wet/dry vacuum to remove any left over stripper from the cracks and crevices. Then neutralize the floor with whatever product the manufacturer recommends and let it dry out throughly.
You should be left with a smooth surface, clean of finish and ready for new coats of finish. This technique helps maintain the patina of the old wood and provides a great option for floors that cannot stand to have another full sanding. The video below outlines Bob’s passive method.
Once the floors have been aggressively sanded or passively stripped you have to do the most thorough cleaning job of your life. All the dust has to be cleaned up or it likely will end up in your finish later and that will make your floors feel and look rough. Using a good vacuum, clean up not only the floors, but also the walls and trim around the rooms because that will also contain dust that can fall into your finish.
After vacuuming use a tack rag moistened with mineral spirits to wipe up any remaining dust from the floor until you can run a white rag across the floor and it passes the white glove test. This is one of the areas that novices fail repeatedly. Not having a completely clean room spells bad finish work later.
Will you be staining your wood floors? If so then I recommend an oil-based stain. Minwax makes plenty of great wood stains you can choose from right here. Before applying your stain I recommend “popping the grain” by wiping the floors down completely with a cloth that has been dampened with water. This opens up the pores of the wood and allows it to take the stain in more evenly. There are wood conditioners on the market that do the same, but water is free and just as effective. This is extremely important with pine floors which are notorious for blotchy uneven stain uptake.
Once the water has completely dried then it’s time to apply your stain. You can simply wipe it on (be sure to apply evenly) with a clean cotton rag. A lot of pros will use a floor buffer to apply the stain over large areas because it goes that much faster. As you apply the stain make sure to wipe off the excess and not leave any stain puddles. I like to apply with one rag and then use a a clean rag in the other hand to wipe off the excess after only a few minutes.
Once the stain has been applied you need to let it dry between 8 and 24 hours to be safe before applying any finish. During this time it’s imperative you keep everyone and everything off the floors since they are not yet sealed. A good rule of thumb is if you can walk over the floors in clean dry socks without getting any stain on your socks then it is ready for application of finish.
Now it’s time for the grand finale! Wood floors perform best with three coats of oil-based polyurethane. You can use water-based polycrylic, but that requires four coats for an adequate finish thickness. You can read up on the differences between the two finishes and why I prefer oil-based finishes in this post
I prefer a satin sheen because it really highlights the character of the wood rather than glossy sheens which obscure it, but ultimately the choice is up to you.
Application of oil-based polyurethane is usually done with a few different methods and it’s largely personal preference. Using a standard roller with an extension pole, mopping it on with a lambswool applicator, or using a T-bar are the most popular. I’m a roller guy because it is easier to keep a consistent finish thickness and the familiarity of the roller helps too. Pour up your finish into a 5 gallon bucket and use a roller screen to avoid drips and puddles.
Be sure to avoid painting yourself into a corner and use a sash brush designed for oil-based finishes to cut in the edges just like if you were painting the floor. It’s important to always maintain a wet edge when applying polyurethane so as to avoid brush marks. Work methodically from one area to the next and don’t skip around. Ensure you have good even coverage and leave it alone to cure for about 12-24 hrs depending on the weather. Warmer temps require shorter cure time and cooler temps require longer.
Sanding Between Coats
I’m gonna make some people angry here, but sanding between coats of polyurethane is NOT necessary. Contrary to what almost every article will tell you you do not need to do it. Does it provide a better finished product? Heck yeah, because with each coat of finish you apply there are little items that get into the finish or the wood grain furs up sometimes and you want a perfectly smooth floor, don’t you?
To sand between coats you need the floor polisher we used in the passive refinishing method earlier. This time use a 150-grit screen to lightly sand the finish and knock off any high spots. After screening you’ll need to vacuum and thoroughly clean the surface again with a tack rag each time. After the final coat of polyurethane there is no need to sand or screen anything. Just let it cure and sit back to enjoy the finished product.
If you do decide to take on refinishing your own floors I hope this post will help set you up for success. You’ve got options with you wood floors. Wood floor refinishing is usually a cheaper option than just about any new flooring option. Running about $2-$3 per square foot, refinishing your floors can be a cost effective way to restore your old house and enjoy the history that rests just under your feet.