While we encourage homeowners to attempt their own hardwood floor projects in order to save money, we believe that there are a handful of projects that are often too frustrating for a DIY project. Among them, one of the more difficult projects is sanding your hardwood floor and prepare the boards for staining.
The problem with sanding is that imperfections are not always visible right away. You may think that everything went right, only to discover, when you apply the stain or the finish, that marks, waves or dips in the floor appear out of nowhere. This has something to do with the reflective quality of the sealer and with the tendency of the stain to highlight imperfections. However, the root cause is often the lack of experience in handling the sander.
Sanders are large, heavy and noisy machines that use a sanding drum or sanding belt to remove the worn sealer and the uppermost layer of the wood. These machines need to be maneuvered with both patience and skill. The challenge consists in controlling the movement of the sander and advancing in a steady way around the perimeter of the floor, for uniform results. This is a learned ability that takes some time to master, so arm yourself with a lot of patience and do not expect everything to go smoothly if this is the first time you use a sander.
If you decide to sand your own hardwood floors, prepare yourself by learning as much as you can about the process. Here are a few common problems when using a drum or belt floor sander.
Using a low quality sander
If you are renting a sander, chances are that it is not of the best quality. It does not help that rental sanders are badly abused, out of tune machines that have seen better days. There is not too much you can do to avoid this problem, short of hiring a contractor. Hardwood floor professionals use pricey, quality machines that are not available in a rental shop, they tune it accordingly, make sure that the drum is not sand clogged, add and correctly align the sandpaper etc.
Not knowing what to expect
You may not be aware that, when the drum touches the floor, the sanding machine starts on its way. This confusing moment is enough to create some problems and leave the floors with unsightly marks.
Another problem is going too fast. Sanding hardwood floors is a question of patience. Unfortunately, if you impose a strict deadline on yourself and plan to do too much in too little time, rushing through the job only increases the probability that you’re going to end up with a marred floor.
Using the wrong grit
In an attempt to not damage the boards or remove too much wood from the floor, you may use a finer grit than necessary. However, this sandpaper may not be enough to remove the sealer. Because it is hard to tell if the floor is properly sanded (especially if this is your first time doing it), you usually find out when you try to apply the stain. With the sealer not properly sanded away, the stain cannot be absorbed into the wood and you end up with adhesion problems or with a patchy stain job.
Thinking that you need to sand only once
A common mistake is to believe that only passing once with the sanding machine over the floor will get the job done. Sadly, things are different. You have to progressively use a finer grit and sand your floor repeatedly and as many times as necessary (usually around four, but your floor may need more).
It is hard enough to obtain a uniform look throughout the floor when using one sanding tool, but it is even harder when using more. Many times, the areas around the perimeter of the room where you use a floor edger to sand the boards end up looking different than the rest of the floor, giving the impression of a picture frame. Buffing the overlapping areas is one way to avoid this problem.
Stopping with the drum still working
A common and costly mistake is stopping on the same spot with the drum still in motion. This usually causes drum marks and ridges. In fact you should only lift or lower the drum when the sander is already in motion, to avoid this problem.
If you attempt to sand your floors for the first time, the details that go into the process may get overwhelming fast. From evaluating the state of the wood floors to deciding on the right grit, and from knowing what sandpaper to use or where to get it from to where you should start sanding and in which direction, all these are only complicated by having to deal with a huge sanding machine that is not inclined to listen and behave.
In fact, we have been summoned many times by frustrated homeowners to fix badly damaged sanded floors. While we encourage you to take on projects that you are comfortable with, we strongly think that, if you don’t have the experience or the time that such a project requires, your best bet is to hire a hardwood floor sanding professional, and avoid costly damages to the floor.