Flooring professionals can sand away as much as 1/16 inches of wood with the coarsest paper. However, some engineered floors cannot sustain more than one heavy-duty sanding, as they may have a surface veneer of only twice that thickness. Refinishing these floors more than once poses a risk of wear-through.
Unfortunately, floorboards are only so thick. Too much sanding can wear them down until they're too thin. When you refinish hardwood too many times, it becomes less structurally sound and more likely to crack. After a few refinishes, it's probably time to get a full replacement.
Hardwood flooring can be re-sanded up to 10 times, depending on how bad the floor is and how skilled the person doing the sanding is. It costs about $2.50 per square foot to refinish a floor, plus $50 an hour for patching and thresholds.
Most solid hardwood planks are thick enough to be refinished up to ten times. Refinishing is essential to caring for your solid hardwood and helps it last longer. However, while solid wood can take multiple refinishing over the decades, we can only refinish engineered hardwood once or twice.
The Golden Rule of Sanding
The golden rule for choosing your sequence is to never skip more than 1 grit. For example, if you start with P80, and need to finish at P240, rather than using every grit from P80 – P220, you can do P80 – P120 – P180 – P240. This sequence cuts out P100, P150 and P220.
This is recommended when the surface imperfections penetrate the finish and affect the bare wood underneath. Once you sand the surface of the floor too many times, you will reach out to the point when the floor is beyond sanding and it is already too thin. Continuing to sand the floor at this point is not recommended.
Floor sanding removes at most about 1/16 inch of wood, and damage that is deeper than that usually will still be evident, though less obvious.
What is this? If you have really, really uneven floorboards, you should start by sanding (with the large drum sander) diagonally to the floorboards to even the floor out and then move on to sanding in the direction of the boards. As a general rule, you always sand with the grain of the wood!
Never use water to clean your newly-sanded hardwood floor. In fact, once they've been sanded, don't use any cleaning products for about 10 to 14 days. Once that time has passed, just use a soft brush to sweep them daily to keep on top of the dirt and dust that naturally occurs.
Sanding jobs can be completed in either three or four passes with different abrasive grits, depending on the condition of the floor being refinished. For old floors, the first pass is to remove the old finish and level the floor. This will be the heaviest sanding and will make heavy scratch marks.
You want to give the new finish time to harden and cure. We recommend waiting a minimum of 24 hours before you walk on your floors– and 48 hours is even better. Start with socks only and keep pets off the floors for a few days.
If you're using both the electric sander and the edger in 140 square-foot floor space, it will take you roughly 5 hours to do three sanding passes. Another thing you must take into account is how old your house is. If yours is 50 years old or more, you'll need extra time to complete it.
If wood gets over-sanded in one spot, it starts to become uneven, with a distorted sort of appearance. This can happen to even the most experienced woodworker. Usually this starts simply by attempting to sand out a discoloration, defect, scratch or gouge.
1-Lightly shade the over-sanded spot
In this step, you need to start by marking the troublesome spot with a pencil, then give the small area around the penciled spot a light shadow. The pencil marks outside the divot will go away as well as the light shadow area. Once they are gone, the wood is good to go.
Buffing mainly addresses damage and imperfections in the sealant layers protecting your hardwood floors. You may want to buff your floors instead of sanding them if the finish of the floor is looking dull and scratched. You can also buff floors made of other materials, like tile, to bring back their luster.
It happens with sanding machines with different grains of sandpaper. Typically, it takes no more than one millimeter of the surface of the boards. It means that if the boards have a thickness of 22 millimeters, they can be sanded more than 5-6 times.
Uneven or sloping floors are very common in older homes, and while it's often a sign of structural damage, it doesn't have to be a dealbreaker.
Your floor needs to be sanded in stages with progressively finer abrasives for the best finish. Starting with grit 40, then grit 60 and finally grit 100 is tipically a good procedure for most wood floors. The goal with the first coarse abrasive is to remove the old surface coating and to flatten the surface.
Professional floor sanding and polishing generally takes a short amount of time — for instance, a typical three-bedroom house with flooring in good condition would take three days for the floor sanding professionals to sand and polish.
In the same respect, most properly maintained hardwood floors can go anywhere from 20 to 30 years without needing any significant work done. Their longevity makes hardwood floors a great investment for any house. However, there will come a time when every hardwood floor will need to either be refinished or replaced.
Sanding wood floors & refinishing yourself will definitely save money, and even an inexperienced homeowner can likely do a better job than the lowest bidding handyperson who quotes on it. Once you understand the basics, a quality final result on your wood floor is more about patience than anything else.
If you sand past 180 grit, the wood dust created by the sandpaper starts getting incredibly small. This wood dust can work its way into the wood pores, and clog them up. This prevents the wood from absorbing stain and finish properly.
If your new floor has a wear layer thinner than two millimeters, it may not be ideal for sanding. However, floors with a wear layer two millimeters or thicker respond well to sanding.
Sanding your hardwood floors takes three sessions with progressively lighter grit sandpaper. To begin, use a coarse 30-40 grit, then a medium 50-60 grit, and finally a fine 80-100 grit.