Sand the Floors

First of all, can we all agree that – with maybe the exception of the waxing the cars – there’s absolutely NO WAY that Daniel LaRusso did all of the things he did for Mr. Miyagi in ONE DAY. Seriously. Who could paint a house in a day? Sand all of that decking in a day? Paint (actually it looked like a semi-transparent stain, but that’s neither here nor there) the fence IN A DAY.

No way.

This does make me want to do a blog post entitled “How Hollywood Sets Up Unrealistic Renovation Experiences,” because it would be amazing. And we all need a good Walter-Sized laugh now and again.

Sorry to be sidetracked. But there was no way I was NOT naming this post after “The Karate Kid,” and I apologize for nothing.

The process of the floors being sanded was so exciting, because it really meant the finish line was in sight. I COULD NOT WAIT to see them. And walk on them.  They just looked so pretty, all clean and fresh!


I’ll let Everett from Virtuoso Hardwoods take over, because he explains it so well in his blog post, so I’m stealing it again! Everett’s words are in blue, mine are in black.

Unlike a typical ¾” thick floor, we can’t just start grinding away on a floor like this. When you have different species of wood with varying densities such as oak or maple vs walnut or mahogany, the softer woods sand much easier and therefore tend to “dish out”. Steel discs on the Multidisc or PowerDrive prevent the sandpaper from flexing down into the softer species, ensuring that the floor will maintain a perfectly flat surface when viewed in the reflection.

If we were to sand the border with the drum sander, then finish off with a sanding screen driven by a maroon pad, the mahogany would definitely develop a concave shape. Not only would this look bad, it would also dramatically reduce the life of the border. We’ve actually had to replace entire sections of border before for no other reason than the mahogany or walnut was sanded too thin. Though it will probably take more time, the safe move here is to only sand on the border with steel discs.

Because of the way these old borders were constructed, not all of the pieces are solidly affixed to the subfloor. Originally these were glued together in a factory, with a thin canvas applied to the bottom. When delivered to the jobsite, they were basically long wide planks that the installer had to cut to size and nail down here and there. The problem with this is that eventually the border gets stepped on a million times and the glue joints break apart, leaving the canvas as the only means of holding many of the pieces down. Most of it is loose, you can push down on it and see the pieces move so I’m nervous about using a waterborne finish on this project. I don’t mind water popping because that will evaporate rapidly, a waterborne finish takes a couple hours to dry and will consist of 3 coats minimum, this has a tendency to edge curl on floors with gaps. I’ll be a lot more comfortable using a conversion varnish or perhaps Rubio Monocoat hardwax oil on something like this.

The challenges don’t end with the border. 5/16” face nailed floors offer unique challenges all on their own. Before any machine even gets powered up, the floor needs to be gone over to check for any face nails at or near the surface. If a nail has worked loose and is actually protruding above the surface, it can actually damage the sanding equipment. But even if they’re just flush with the surface, they will quickly dull the sandpaper and we’d just be throwing money away. Punching nails just below the surface, but not too deep, is a time consuming but necessary aspect of refinishing these floors. How often nails will need to be set during the process is generally determined by how many times the floor has been sanded. If there’s still quite a bit of life left in the wood then most of the nails likely will not have been sanded down to. Conversely, if one of these floors has been sanded many times, it’s likely that most of the nails will need to be set throughout the sanding process. (Amy edit : You’ll see this process in the first youtube video at the end of Everett’s words!)

Then there’s the issue of trowel filling to deal with. Generally we don’t like to trowel fill floors because wood moves seasonally due to fluctuations in moisture. If you fill gaps with filler, the wood will eventually either expand, pushing the filler up and out, or the wood will shrink and the filler will separate, leaving a bad looking jagged line in each gap. Trowel filling face nailed floors is a little different though, some say you should compromise on the gaps in order to fill the nail holes. We began offering this service for face nailed floors years ago, but have only trowel filled a handful of times. I don’t know if it’s a regional thing, or if people really appreciate the history aspect of these floors and see trowel filling as sort of trying to “hide” that history or what. They would have been filled when new, so from a purist standpoint they should probably be filled. The way we handle it is to offer it as an add-on and let the homeowner decide. In this case, the client opted to have us fill this one. An issue specific to this job is the color difference between the old wood and the new installation. If we were to use a pre colored filler, it would likely only match the new wood. Instead, we’re going to use a product that mixes with fine wood dust and mix 2 batches to prevent that problem.

There is much more to cover in regards to the sanding process on this floor, but at some point I get rambly and too generalized rather than sticking to aspects of sanding that are particular to this project. So that’s all that occurs to me for now, at some point I’ll put some thoughts down about the process of choosing a color, and eventually the actual finishing process.

Some videos! As a band director, the nails being set in this one are so percussive and FUN!

And also :

During the process, once the floors were sanded we found some more “fixes” from previous owners in the dining room. Here, they filled in come floor rot with – we think – plaster. We opted to have the boards removed and replaced with old wood that matched.




Old board out!

New board in. PERFECT.

One more spot, same process. Check out the rot of the board that was removed on the left! Now, if I did karate, I could totally bust through that. (SEE WHAT I DID THERE? Full circle “Karate Kid” references.)

The step treads were also sanded by hand. We’re leaving the risers as is.

Stunning attention to detail.

Okay – here’s some eye candy – the sanded floors!!!!


They’re SO LOVELY. Next up – color and finish!


  1. Is there anything more satisfying than sanding a floor? Cannot wait to see the finished product!

  2. Wow. Those floors are so pretty! I can’t wait to see them with the finish on. QUESTION: What did you do with all the furniture? Did I miss something in a post about that?

    1. I don’t remember if I put it in a post or not – but it’s all crammed in a bedroom on the second floor. We hired movers to move it all upstairs!

      1. You should definitely take a photo of that. I bet it looks like advanced Tetris in there.

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