DIY Wood Floor Sanding: Common Pitfalls of Sanding Wood Floors Yourself

It’s not uncommon to get a call for a floor sanding estimate in which the conversation starts with, “I have wood floors in my house, and I am considering doing it myself.”   The truth is, wood floor sanding is a popular do it yourself project and often an intriguing challenge enticing many homeowners looking to get their hands dirty.  It’s also no secret that sanding wood floors is a labor intensive undertaking, so it goes without saying that there is some serious sweat equity in taking on the floor sanding project yourself.  However, for every successfully sanded wood floor, there is horror story of things gone awry.  Material and rental prices getting out of hand, rental equipment being inadequate for the job, the project taking way too long and subsequently having your floor out of commission for weeks, not having enough experience for laying the floor finish, or, worst of all, ruining your hardwood floor with “drum marks” and “edger divots.”

Make no mistake, you can ruin a wood floor if you improperly sand it.  And, since a 400sqft maple flooring is worth about $2000 in just materials, it’s not an easy mistake to swallow.  However, most of the common mistakes in sanding a wood floor yourself can be easily avoided if you understand why they happen.  That is what this blog is about.  We are going to discuss the major DIY floor sanding pitfalls and how to avoid them.

Equipment:  Any professional floor sander worth their salt will have a drum sander that runs on 240v power and weigh in at around 180lbs or more.  These machines are the backbone of their wood floor sanding service and cost over $6000.  You will never find these machines at a rental shop and, therefore, have started with a disadvantage.  Most rental companies will have a 120v belt sander such as the EZ 8 by Clarke.  These machines have very little power and are often so beat up and out of tune that they leave terrible chatter on your wood floor (chatter is not good!).  The other option you may see is a planetary sander which uses a single head or 3-4 heads that rotate on the bottom of the machine, such as The Sander by U-Sand.  These are wonderful DIY sanders since it’s nearly impossible to ruin your floor with them and they can’t leave chatter like the belt sander.  So whats the catch?  Read on.

Old Finish Removal: The catch is, you have to sand the old finish off the floor first.  The problem with planetary sanders is they lack the aggressiveness to cut the old finish effectively.  Obviously, sanding the old finish off is the first step, and it’s also the step during which most people abandon the project and pick up the phone.  This is because they find that after several hours of sweating in a dust filled room, attempting to sand their tiny bedroom, they have hardly made a dent.  If you are willing to put in the time, there are a few planetary machines that can get the job done, but finding them in your town may be a challenge.  And when you do find a good one, the rental place needs to stock a low enough grit sandpaper to start with.  This brings us to our next pitfall.  (More about the correct process on our Floor Sanding Process page).

Material Costs:  So you found a wonderful floor sanding machine to get the job done, but what sandpaper should you use?  Most rental areas stock paper starting at around 36 grit for belt sanders and 50-60 grit for planetary machines.  Unfortunately, the quality of the paper is of the worst kind and it priced like it’s made of gold.  When we start most refinishes, we usually begin with 36 grit premium 3M paper.  If the floor has really sticky shellac or mastic, we will go as low as 16 or12 grit.  You won’t find these grits in the stores.  This is where people get into trouble.  Since the paper is so expensive, they buy a few pieces of the lowest grit they can get their hands on.  They start sanding their wood floors and find the paper is clogging up with finish long before it gets dull.  Quickly finding that clogged paper is useless, they go back and buy more paper which clogs and the cycle continues until they realize material prices are out of hand.  You may start to question whether you really want to tackle sanding your wood floors at this point, but let me provide a few easy solutions to you at this point.  Find the paper that fits your machine online and get the proper grits.  The paper should be of better quality at lower prices.  Also keep in mind that the belt sander is a more aggressive floor sanding machine compared to the planetary sander, so you may be able to rent this machine first, in order to get the old finish off, and rent the planetary sander to provide the finish sanding.  This is an excellent strategy as long as you don’t ruin the floor with the belt sander.  Which brings us to the next problem.

Ruining Your Wood Floors:  Belt sanders can be notorious for leaving large drum marks when improperly run or tuned.  The problem occurs when you drop the drum without have the sander in motion.  The drum will spin in one spot until you have a small divot at best, or a large hole in the worst case scenario (this would take some serious daydreaming though).  The problem is, even the smallest discrepancy with a belt sander will show after the floor is finished, even if it wasn’t noticeable before the finish was applied.  This can also be cause by improper edging.  I have never seen a 120v belt sander that can leave a floor flat.  However, as long as you don’t leave large drum marks the smaller ones can be smoothed out with the finish sanding of the planetary sander.  This is why these two machines compliment each other so well.  But, this can’t be stressed enough, the planetary sander will not remove large drum marks.  If these occur, you’ll have to feather them out with the belt sander or edger.  And, now that your wood floor is sanded, what next?

Finishing Your Wood Floor:  Applying finishes is not easy, but a little information will allow you to avoid some big mistakes.  First, since you wouldn’t want to waste all that time you spent sanding your wood floors, don’t skimp on the quality of the floor finish.  The best finishes today are mostly water-borne urethane’s and cost between $50 and $110/gallon for something of quality.  Unfortunately, you won’t have access to these finishes and, if you did, water-based finishes dry way to fast for a DIYer to use.  You would end up with lap marks all over.  Your best bet is to buy an oil-based polyurethane and attempt to get your hands on the highest quality you can.  If you can find Primero by Poloplaz or DuraSeal they will give you great results.  If not, Varathane can be found at Menard’s and isn’t too bad.  Although oil-based finishes don’t have the durability of water-based wood floor finishes, they can still provide a beautiful floor.  Just remember, oil-based polys are dangerous if not handled safely.  You must, must, must ventilate your house when finishing your floors and wear respirators.  More about products on our Finishes page.

You may wonder why a hardwood flooring company would give advice to homeowners on how to better sand their wood floors.  Wouldn’t this be taking away from potential business?  Not really, because most DIYers who like a challenge are going to want to attempt the project at least once and since Natural Accent Hardwood Floors is a hardwood flooring service company, we include hardwood education as one of our services.

We are always willing to take the time to provide information to those seeking a little assistance in their hardwood flooring projects.  If you can’t find what you need on our website, give us a call and we can answer your questions over the phone.  And, as long as you are in town, we are willing to swing by and take a look at your project to give you better and more specific advice.

We are thinking of starting a DIY page of before and after pictures.  Just take a before and after of your wood floors and send them to us.  If your project doesn’t go so well, send that picture as well.  If we compile enough pictures, we may start a “Wall of Fame” and “Wall of Shame” with prizes to be won.

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  • What our customers have to say…

    “We so appreciate Jim’s professionalism, honesty, respect, eye to detail, and woodworking skill. He is a perfectionist not only with the install but also with the cleanup at the end of each day. Our beautiful new floors have dramatically changed the look of our home and everyone who comes to visit will comment on the change. We are extremely happy with our new floors.”

    Ron and Carol Halverson, West Fargo, ND

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