How to Efficiently Sand Your Wood Floor

I just refinished a wood floor in our house. Like a good Do-It-Yourselfer, I watched lots of videos and read lots of guides on how to do this correctly. I’m glad I did, but I learned a few things that aren’t covered in those guides. In this article, I’ll tell you how to approach the project as a first-timer instead of a pro, I’ll give you a guide for estimating how long it will take to sand and finish your hardwood floor, and I’ll expose some hidden “gotcha’s” that aren’t covered in the videos. I’m assuming you’ve already removed carpet and carpet tack strips, as well as any tile. And that you’ve dealt with any protruding nails (use a nail set) and staples (remove with a pliers). You should be starting with bare or painted wood.

Be Safe
Please, please, PLEASE. Use safety goggles. Wear earplugs. Wear a dust mask. Wear sturdy shoes to protect your dainty toes. Ensure proper and active ventilation. Just opening a window isn’t good enough. Use a box fan to pull air out of the room. Everyone will be healthier, you’ll have less dust to clean up, and floor sealers will dry faster. A box of earplugs costs a couple of bucks and makes a great stocking-stuffer for someone you care about. They will thank you when they’re fifty years old and can still hear you when you say how much you love them.

Do-It-Yourself is different than Do-It-Pro
Many of the expert videos show you how professionals sand a wood floor. Problem is: they’ve done it before. They already made their mistakes and have practiced using the tools. As a DIY, you’re first time may be your only time. And you want your first time to be perfect – or nearly so. Because of the high stakes involved, I recommend doing the sanding in reverse!

Four tools for sanding floors
Before I go any further, there are four tools used for finishing wood floors: a drum sander, an orbital sander, an edge sander and a palm sander. These can all be rented from major hardware stores, typically for four hours or an entire day. I recommend four hours and I’ll explain why later on.

Drum sanders are the weapons of mass destruction in the floor sanding trade. You can take off a lot of wood in very little time. They are heavy, awkward and aggressive. In untrained hands, they behave like scared badgers, bolting in unexpected directions. Professionals use them to remove paint and major gouges. DIYers use them to carve unrepairable divots.

Orbital Sanders are kinder, gentler drum sanders. They stand about four feet high and have three sanding pads. They twist slightly when starting up, but won’t go skittering across the room. They have a dust containment system that surrounds the pads, but prevents the sander from getting next to the wall.

Edge Sanders or Edgers are designed to get next to the wall and into corners where orbital and drum sanders won’t go. They look like routers and require getting down on hands and knees. If you have a bad back, convince someone else to do this for you.

Palm sanders are loud, handheld tools. They are great for tight corners and light touch-up. Did I mention wearing earplugs?

One more tool
An overpowered shop vac is your best friend. If you don’t believe me, turn on that orbital sander for five minutes. The room, and your lungs, will be filled with dust. Your housemates will curse you for weeks to come as they try to remove the fine dust from every surface, including the top of their morning coffee. All of these sanders come with ports that can be attached to a shop vac. Use duct tape to ensure a snug fit. Empty the shop vac daily (outside) and be sure to clean the filter.

While you’re considering the shop vac, also consider turning off any forced air heating or cooling as well as sealing the room. Keep the dust in the room if at all possible.

Oh. And About Sandpaper
Sandpaper is cheap. Buy a lot of it – assume you’ll change it out four times. Most stores let you return what you don’t use, so don’t bother economizing. Buy 30 grit, 60 grit, and 100 grit (or close approximates). Get some 150 grit if you’re an overachiever. By the way, the bigger the number, the finer the finish. And different sanders require different sizes and shapes, so be sure to ask for recommendations.

30 grit won’t plug up with paint as fast as 100 grit, but will leave scratches. 100 grit will leave a nice finish, but any paint on the floor will quickly plug it up and render it useless.

Big Tip Number One: Reverse the Process
Every video I watched said to start with a drum sander, then use an orbital sander, then an edger, then a palm sander. For professionals, this makes sense. They’ve practiced and know how to use the tools. For us DIYers, I’d advise going in the opposite direction. Use a palm sander, then an edger, then an orbital. Forget about the drum sander, that’s only for ninja warriors — not weekend warriors. I’m suggesting this method because it is easier to cover your mistakes. Small tools like palm sanders and edgers tend to gouge and leave tracks. Larger orbital sanders can cover up those mistakes.

Start with a palm sander and use 30 grit to sand out just the corners. Sand the corners to a radius of about eight inches. If you have paint on the floor, it might require changing sandpaper two or three times. Get down to bare wood, then change to 60 grit and repeat. Take heart, the 60 grit will go faster. Then finish with 100 grit. Stop to admire how smooth that wood is now!

Now – head off to the hardware store and rent an edger for four hours. There are several videos on how to properly adjust and use them, so I won’t repeat that advice here. Again, start with 30 grit and sand to bare wood within a foot (no further) of the edge of the room. Be sure to overlap the areas you’ve already covered with the palm sander. Change out to 60 grit, then 100 grit.

Stop. Take a break. Get someone to massage your back. Don’t operate power tools if you’ve been drinking alcohol.

Finally, rent an orbital sander for floors (not a hand sander). Repeat the 30 – 60 – 100 grit process on the entire floor. Be sure to overlap the areas you’ve already done with the palm sander and edger. When you’re finished, you should be gouge-free and smooth as an insert-your-own-analogy-here. now you’re ready to apply a sealer.

How long does sanding a wood floor take?
My experience was with a 10 foot by 12 foot room and it took us about fourteen hours of solid work. But that doesn’t mean fourteen straight hours. We broke it up over three tools and four days.

The palm sanding goes quick. Maybe two hours total. Some of that is spent adjusting the ventilation, cleaning the shop vac, finding extension cords, sealing off air vents, or turning off the furnace blower.

We used the edger for less than four hours. It goes quick, but it does gum up with paint. Again, don’t scrimp on sandpaper.

We rented the orbital sander for two four-hour sessions. We could have rented it for a full day, but it was nice to take a break. Refinishing floors is a game of patience – if you rush it, you’ll be tempted to cut corners and do a “good enough” job when you should have paid attention to detail.

In the end, accept some imperfections
Let’s face it. You’re not a professional and there will be some rough spots. If you want perfect, hire someone who does this for a living. But you can do a pretty acceptable job if you take your time and learn to live with the “natural beauty” of an old wood floor.