I run into customers all the time that ask me, “How many times can you refinish an oak floor?
Short answer is 4-6 times depending on how much damage has to be sanded out with each refinish. This answer is subject to change depending on factors such as evenness of the floor, thickness of the wood, and depth of existing damage with each refinish.
The first big factor that determines how many times an Oak floor can be sanded, is the evenness of the floor. Over time, foundations sink, joists sag, and subfloors become weaker. All these things cause the flooring planks on the surface to move slightly. These slight movements can turn into to a real problem for the longevity of your floor over time.
A traditional Oak floor is ¾ inches think. However, you cannot sand all the way down to the bottom. You can only sand to the bottom of the wear layer. The wear layer consists of all the wood that is over top the tongue and groove. This measures 6 millimeters or about ¼ inches on ¾ inch hardwood. The average floor refinishing takes off about 3/64 of wood. So let’s look at this chart of how much wood is left as the refinishes take place.
At Six Refinishes, you are down to nothing left. You really can’t take it down to nothing. So realistically, you would be looking at 4-5 refinishes on the average floor. Sometimes you will be able to get away with more if you’re dealing with a floor that is very flat.
So how does evenness play into all this?
The biggest factor that decides how many refinishes you are going to get is evenness. The most difficult part of sanding a floor down is getting everything even. If some boards have shifted up and others down, you may have to sand a full 1/8 of an inch off in some places to get rid of any sharp edges on boards. That means you instantly cut the wear layer in half. You would probably never have to cut an 1/8 inch of the entire floor, however, there are situations where you might have to.
Many pre-finished woods (wood that comes with the factory with a finish already on it) have bevels on the edges. These bevels are to protect the wood as it is installed. When you don’t have the bevel, you will have a sharp and easily damaged edge. This is not a problem for site finished flooring (raw wood that is installed then sanded) because you can sand and fill to take care of any damage. Once the sharp edge is closed into the floor on a site finished floor, it can no longer be damaged and makes for a much tighter and better looking floor than pre-finished with bevels. There is a reason we are talking about this. When you go to refinish a pre-finished floor with bevels, those bevels will go much deeper into the wood than you would like to go while doing your average refinish. I typically recommend just leaving the bevels when you refinish. You can still sand the top off and change the color. If you decide to have someone sand the bevels out, just know, you are cutting the life of your floor down by several refinishes.
Let’s talk about wood thickness
We already covered that traditional wood flooring is ¾ of an inch thick with a 6mm (.24 inch) wear layer. 90% of solid hardwoods will fall into this category. It does not apply to just Oak flooring. Many homes have Pine, Douglas Fir, Walnut, Hickory, Brazilian Cherry or Ash that measures exactly the same. Over the years there have been different thickness of flooring that have come out that you might have in your home.
5/16 Top Nail
Where I am in Southwest Michigan, (St. Joseph to be exact) you never run into this stuff. However, in Indianapolis for example, we sanded it almost every week. It was used in many homes built in the early 1900s. It is just thin little boards traditionally made out of White or Red Oak. Many of them are quarter sawn. (I’ll do one on this soon) It measures 5/16 thick and came in a few various widths. Many hardwood companies that are not familiar with it, think it cant be refinished. This is false. We would get typically 3 or so refinishes out of a 5/16 top nail floor. These floors are very beautiful but not very practical. They moved a lot and don’t feel solid at all like traditional ¾ wood.
3/8 Tongue and Groove (T&G)
Occasionally I will run into an early 1900s home that has a very thin Oak flooring that measures about 3/8 thick and has a tongue and groove. These floors are practically garbage. Because they have a wear layer of 1/8 (or less). These floors usually cannot be sanded. Not because they are too thin though, it’s because they are always uneven, like we said before, when the floor is uneven you can easily take off an 1/8 of inch. If the floor is perfectly even. They have 1 sanding in them. A risky sanding. I would save my money and just invest in new ones though. It’s not worth it. You may run into new products that match this description as well. Just walk away. You will thank me later.
Engineered flooring means the floor is made in a factory with a plywood base with a tongue and groove. On top, you will have a layer of real wood. It can come as raw (finish on-site) or pre-finished. (like most new floors today) The question that’s crucially important is, “how thick is the wear layer?” If it has a 6 or 4 mm wear layer, it is good quality product that you will be able to refinish 4—6 times for the 6mm and 3-4 times for the 4mm. In well to do areas of the country like Boulder Colorado, Wood Wise Hardwood Flooring puts in tons of these beautiful high end engineered floors. In many instances, an engineered floor is more resistant to moisture allowing for wider planks. Many floors do not have wear layers this thick though. Many have a very thin 2 or 3 mm wear layer. These floors are very risky to attempt even one sanding on. If they are perfectly flat, then it is possible. Again, while possible for 2-3 mm wear layers, it is a poor investment to refinish them or to even buy them in the first place.
This is as simple as it sounds. How deep is the damage? If your floor had a piano pushed across it, I can tell you it is probably some pretty deep damage. You will have to sand possibly up to an 1/8 of an inch out in those areas to get all the damage. You can see how that deep damage can ruin a floor really quick. If you have deep damage in your floor, you might consider not sanding it all out at the time of a refinish. This will allow you to be able to get more years out of your floor. It just depends on how much that remaining damage will bother you. To prevent deep damage, you should be doing a new coat on top every couple year. The good thing about Oak, is that it wears quite well over time compared to softer woods like Pine and American Cherry.
How long do other woods last?
You may not have realized it, but the type of wood you have in your home will drastically effect how long it will last you. I’m talking about the species here and not the thickness. There is a thing called the Janka Hardness scale. (Google it) This scale measures how hard a wood is. The harder the wood, the more refinishes you will get out of it. A Pine or Fir flooring may only last for 2 refinishes simply because the softness of the wood allows the damage to penetrate deeper. I have seen Pine floors that only got one refinish out of them due to the depth of the damage. Compare that to a much higher hardness wood like Hickory. Hickory will last for probably 5-7 refinishes. That’s because Hickory is so hard that the damage can only penetrate the very top fibers in the wood.
So, what flooring can be refinished the most times?
There is no right answer to his question, but floors like Hickory, Brazilian Cherry and Pecan will typically last a couple more refinishes than Oak, and 2x as many refinishes as Pine or American Cherry.
Getting the most refinishes possible
If you care for you floor properly, you will get a lot of life out of no matter what it is. Things to avoid are:
- Lots of moisture (mopping your floor with water)
- Deep damage (pushing fridges across, dropping heavy items etc.)
- Heavy and energetic dogs (Doggies can destroy any floor)
- Pet urine (will turn spots black and require deep sanding or patching)
- Shoes (Socks keep even a pine floor nice)