The very first step is actually educating yourself on the process—what machines to use, how to use them, and what each step is intended to accomplish.
The amount of time and effort a homeowner will need can easily be three to five times greater than that of a professional C-15 licensed flooring contractor. If you are not accustomed to physical labor, that makes the job considerably harder.
After you have educated yourself on the process and how to operate the machines, you can move toward the actual start of the project.
It All Starts With a Floor Assessment
When assessing the hardwood floor, you are looking for a few things.
Species Identification
Identifying the species will help determine your options. One of the first decisions is whether you want to keep the hardwood a natural color or stain the floor to change its color.
Different species of hardwood respond differently to sanding and stain, so knowing what you are working with is important before you begin.
Look for Physical Problems With the Floor
Inspect the floor for:
- Discoloration
- Broken boards
- Termite damage
- Water damage
Any problems with the floor should be corrected before dropping a sanding machine onto it.
Floor Preparation
The Rooms Must Be Empty
The entire floor should be cleared of all furniture and obstructions.
If you plan on sanding one room that connects to another room with hardwood flooring, there are some serious potential hurdles you can encounter. My recommendation is to sand all connecting floors so everything matches at the end of the project.
Remove floor vents and place a small towel in each opening to help prevent dust from entering the ductwork.
Check the Floor for Protruding Nails
If you find any protruding nails, set them below the surface. A single nail can cause serious damage to the sanding machine's drum.
Thoroughly Sweep the Floor
The floor must be thoroughly swept. Any small object can interfere with the sanding process and potentially damage not only the sanding machine, but the floor as well.
Choosing the Right Equipment
Most people don't own professional-grade floor sanding equipment, so they turn to rental yards.
Rental-yard representatives are not necessarily experts in the operation of every machine they rent, so any advice you receive should be carefully scrutinized.
I'm sure there are plenty of YouTube videos available to watch, but videos can only take you so far. Properly operating professional sanding equipment requires hands-on experience.
To put that into perspective, a contractor in training at National Floors will usually participate in sanding somewhere between 25 and 50 floors before working unsupervised.
That should give you some idea of the learning curve involved.
The Bare Essential Equipment You Will Need
- Belt sander
- Edger
- Buffer
- Sandpaper for all of the machines
Materials Needed
- Wood filler that matches the species of hardwood
- Sealer
- Finish
If you are new to this, I would avoid using a water-based finish because it dries very fast. An oil-based finish will give someone without professional experience more working time.
Other Tools You Will Need
- Putty knife
- Scraper
- Additional sandpaper
- Maroon burnishing pads for the buffer (240 grit)
- Sanding screens for the buffer
- Pole-type finish applicator
- Hand applicator
- Vacuum and bags
- Garbage bags
- Broom and dustpan
- Non-marking shoes
- Knee pads
- Work gloves
- Nail set
- Hammer
Sanding Strategy
Roughing the Floor
Roughing the floor is essentially the first cut. Its purpose is to remove the old finish and flatten the floor.
The grit used should be aggressive enough to accomplish this, but this is also where a lack of experience with a belt sander can become catastrophic. A professional floor sander is an extremely aggressive machine, and mistakes can damage a hardwood floor very quickly.
The belt sander is used in the field, while the edger reaches the areas the belt sander can't reach.
The belt sander is always used in the direction the floor is laid. Never sand across the boards.
Once the initial roughing has been accomplished, the edger is used around the perimeter of the room where the belt sander could not reach.
The edger is also a very aggressive tool and doesn't necessarily require the same aggressive grit used on the belt sander.
Vacuuming and Applying Wood Filler
Once the perimeter of the room has been edged, it's time to vacuum.
After the floor has been thoroughly vacuumed, it's time to apply wood filler.
This is not putty. This is a thin wood filler designed to be spread into small cracks and imperfections in the floor. It is intended for hairline imperfections, not substantial gaps.
If you apply this type of filler into large gaps, it will eventually crack and come out. You don't want that.
The Second and Third Sanding Passes
After the wood filler has dried, it's time to use the belt sander again.
This time, the grit is a little finer. You cannot skip more than one grit during this process.
After the floor has been sanded a second time, it's time to go finer again with the belt sander. I recommend finishing at 100 grit.
After the field has been sanded three times in total, it's time to edge the floor again. Again, I recommend finishing with 100-grit paper.
Scraping and Sanding the Corners
After the perimeter has been sanded with the edger, use a paint scraper to reach the corners of the room.
This requires relatively aggressive scraping. Your goal is to remove all of the old finish from the corners and level those areas with the adjacent floor.
Then use sandpaper to repeat the same sanding sequence you used on the field.
For example, if you started with 50 grit in the field, use 50 grit in the corners. If you progressed to 80 and then 100 grit, treat the corners the same way.
The goal is to create uniformity throughout the entire floor.
Buffing the Hardwood Floor
Once the sanding and scraping are complete, it's time to buff the floor.
Using a buffer is not simple. A professional floor buffer is strong enough to throw a grown man into a wall if it is used incorrectly.
The perimeter is buffed first, followed by the field. The screen used depends on the color choice.
Let's say you are moving toward a natural color and will not be applying stain. In that case, the buffer screen should be approximately 100–120 grit.
The finer the grit, the tighter the grain will be.
If you are staining the floor, keep in mind that a finer grit will make the stain lighter than you may have intended.
Preparing the Floor for Sealer
Once the floor has been buffed, it's time to vacuum again.
A thorough vacuuming is absolutely necessary to avoid contamination when applying the sealer and finish.
Now it's time to start applying the sealer.
Follow the directions on the label. Start at the furthest point of the room so you don't paint yourself into a corner.
Apply the sealer in the direction of the flooring.
If you choose to use a roller, make sure the roller is designed to accept the sealer or finish without breaking down and contaminating the floor.
Also, make sure the roller nap is thick enough to achieve the manufacturer's required spread rate.
For example, if a quart of finish is intended to cover approximately 100 square feet, you need to apply enough material to achieve that coverage. If you press too hard on the applicator and stretch that same amount of finish over 150 square feet, the floor may initially look great, but you haven't applied enough protective material.
Less protection equals less life.
Burnishing After the Sealer Dries
After the sealer is dry, it's time to burnish the floor.
Wetting hardwood creates what is known as grain raise. If you run your hand across the floor, you will be able to feel the raised grain.
We need to knock that grain back down.
Using approximately 240-grit paper, lightly sand the perimeter by hand. This is a relatively quick process. Your goal is simply to knock down the raised grain, not remove the sealer.
Then do the same thing to the field using the buffer.
Using a maroon pad on the buffer, work the perimeter first and then the field, overlapping your buffing pattern.
Clean the Floor Again
After the floor has been buffed, it's time to vacuum again.
After vacuuming, get a flat mop and a small white towel. Pour a small amount of mineral spirits onto the towel and mop the floor in one direction using an "S" pattern.
This is vital for picking up anything the vacuum didn't get.
Applying the Finish
Now it's time to apply the finish.
Again, read the directions.
The finish is applied the same way as the sealer. Start at the furthest point of the room, first cutting in the edges with a hand applicator.
After that, use the pole applicator to apply the finish.
Think of it like ketchup. If you don't have enough on the floor, you can always add more as needed. It's much the same as ordering fries—you don't dump the entire bottle onto the plate. Add more as needed.
Again, there is a spread rate you should attempt to match.
Non-professional products are typically lighter in viscosity and contain a lower solids content. Essentially, this means over-the-counter finishes generally won't last as long as professional-grade products.
Make sure the windows are open so the room can ventilate and dry properly.
Take your time when applying the finish. Have the lights on in the room, if possible, and use the reflection across the floor to inspect your work.
Make sure you don't leave swirl marks or other application marks in the coating. If you see any, straighten them out while the finish is still wet.
Let the Finish Dry
This is an extremely important part of the process because you will need to burnish the floor again before applying the next coat.
A floor can appear dry on the surface before the finish has dried sufficiently to be safely burnished. If you attempt to burnish the floor too soon, the coating can gum up and create a major problem—potentially requiring you to sand the floor again and repeat much of the finishing process.
My recommendation, particularly for someone doing this for the first time, is simple: let the floor dry for an entire day.
Don't become impatient because the surface looks dry. Giving the finish additional drying time is far better than discovering during burnishing that it wasn't ready.
Keep the temperature in the house at least 70 degrees Fahrenheit.
Burnish Between Coats
After the finish has dried for the entire day, it's time to burnish the floor again. Don't forget the edges.
The purpose of this step is to knock down the grain raise and prepare the existing finish so the next layer can mechanically bond to it.
If you skip this step, you risk the floor delaminating in the future. So don't skip it.
After burnishing, thoroughly clean the floor again before applying the next coat.
Use Light and Reflection to Check Your Work
Use light and reflection to inspect your work frequently.
This is especially important while applying the finish because once you move away from a section, you may not be able to walk back onto the wet floor to correct it.
Let the Floor Dry
After the final coat, let the floor dry.
You will generally be able to walk on it in 24 hours and put the furniture back in approximately 48 hours.
When replacing furniture, lift and place it. Never drag it across a newly finished hardwood floor.
So, How Difficult Is DIY Hardwood Floor Refinishing?
That's it. I hope your floors turned out well.
If this sounds like a lot of work, that's because it is.
Sanding and refinishing hardwood floors isn't simply a matter of renting a sanding machine, removing the old finish, and applying a new coat. Every stage affects the next one. A mistake made during the sanding process may not become obvious until stain or finish is applied, when correcting it becomes considerably more difficult.
That's why I rank DIY hardwood floor refinishing a 10 out of 10 in difficulty if your goal is to produce professional-grade results.
The major concern should be, what if my hardwood floors don't turn out to the expected appearance? Well, that means it's probably a do over! When National Floors sand and finishes your floors, you get a 2 Year Warranty.
