A Pro's Guide to Refinishing
Hardwood Floors

A Pro's Guide to Refinishing Hardwood Floors

Refinishing hardwood floors takes time, expertise, and the right equipment, creating a dramatic end result. Follow our guide to ensure your customers enjoy the transformation of an old hardwood floor into something fresh and beautiful.

A pro painter refinishes a hardwood floor.

The right determination and expertise can often restore neglected hardwood into a distinctive showpiece.

Your first task should be to determine the full scope of the job before you start: Will this be a basic sanding and new topcoat (called a “screen and recoat”)? In other words, is the floor in good condition? Or is there damage or a color change that will require a more involved project? Remember that a polyurethane top layer is, by its nature, sacrificial. Polyurethane is meant to protect the floor from the everyday wear of foot traffic, pets and minor spills that could otherwise damage the stain or even the wood itself. Damage to the polyurethane layer is normal and does not necessarily mean the wood underneath is damaged.

Carefully inspect the condition of the floor: Is there any bare wood visible? Are there uneven wear patterns in the stain coat? Are there any signs of the wood cupping (plank edges higher than the middle) or crowning (plank middle higher than the edges) from moisture imbalances? Are there any water or pet stains? If the answer to any of these questions is yes, then you can expect to have a more detailed job on your hands.

The type of floor you’re working with will also inform the project’s scope:

Solid wood has a thick wear layer and can be refinished many times.

Prefinished or factory-finished wood has a thinner wear layer and can’t be refinished as much as solid wood.

Engineered wood, made up of several thin layers, can only be refinished once or twice at most.

Not sure which type of flooring you’re dealing with? You can assess the material by removing an HVAC floor grate or by checking the border between the wood floor and carpet to get a good look at the end of a plank. The amount of wood above the tongue and groove (the interlocking ridges and valleys on the sides of the plank) shows the thickness of the wear layer, which will show you whether it is solid wood, prefinished or factory-finished, or engineered.

Important
Safety Note

Make sure to use goggles or glasses, ear plugs, respirator mask and kneepads to protect yourself.

The right determination and expertise can often restore neglected hardwood into a distinctive showpiece.

Your first task should be to determine the full scope of the job before you start: Will this be a basic sanding and new topcoat (called a “screen and recoat”)? In other words, is the floor in good condition? Or is there damage or a color change that will require a more involved project? Remember that a polyurethane top layer is, by its nature, sacrificial. Polyurethane is meant to protect the floor from the everyday wear of foot traffic, pets and minor spills that could otherwise damage the stain or even the wood itself. Damage to the polyurethane layer is normal and does not necessarily mean the wood underneath is damaged.

Carefully inspect the condition of the floor: Is there any bare wood visible? Are there uneven wear patterns in the stain coat? Are there any signs of the wood cupping (plank edges higher than the middle) or crowning (plank middle higher than the edges) from moisture imbalances? Are there any water or pet stains? If the answer to any of these questions is yes, then you can expect to have a more detailed job on your hands.

The type of floor you’re working with will also inform the project’s scope:

Solid wood has a thick wear layer and can be refinished many times.

Prefinished or factory-finished wood has a thinner wear layer and can’t be refinished as much as solid wood.

Engineered wood, made up of several thin layers, can only be refinished once or twice at most.

Not sure which type of flooring you’re dealing with? You can assess the material by removing an HVAC floor grate or by checking the border between the wood floor and carpet to get a good look at the end of a plank. The amount of wood above the tongue and groove (the interlocking ridges and valleys on the sides of the plank) shows the thickness of the wear layer, which will show you whether it is solid wood, prefinished or factory-finished, or engineered.

Important
Safety Note

Make sure to use goggles or glasses, ear plugs, respirator mask and kneepads to protect yourself.

The Basic Project:
How To Screen and Recoat
a Hardwood Floor

The Basic Project:
How To Screen and Recoat a Hardwood Floor

Provided you have the right equipment and expertise, if the floor is in fundamentally good shape, a screen and recoat (basic sanding and a new topcoat) can have it looking brand-new in a minimal amount of time. As always, the right safety gear is important, so make sure you have goggles or glasses, ear plugs, respirator mask and kneepads.

Basic Refinishing Supplies Checklist

Scraper

Vacuum

Buffer

Maroon buffing pad

Screen

Sandpaper

T-bar and coater
checkmark icon

Natural bristle brush

Rags

Polyurethane topcoat
checkmark icon

Watering can
checkmark icon

Painter's tape

Goggles or glasses
checkmark icon

Respirator mask
checkmark icon

Ear plugs

Kneepads

Basic Refinishing
Supplies Checklist

Scraper

Vacuum

Buffer

Maroon buffing pad
checkmark icon

Screen

Sandpaper

T-bar and coaster
checkmark icon

Natural bristle brush
checkmark icon

Rags

Polyurethane topcoat
checkmark icon

Watering can
checkmark icon

Painter's tape
checkmark icon

Goggles or glasses
checkmark icon

Respirator mask
checkmark icon

Ear plugs

Kneepads

1. Prep the Room

Correctly preparing the surface is just as important as what you put on it. Start by removing all contents of the room, including furniture, any floor-mounted HVAC grills, pipe collars around radiator supply lines, shoe molding (the strip of molding where the baseboard meets the floor), and any other obstructions.

Use painter’s tape or masking tape to protect baseboards from sanding equipment. Be sure to countersink any nails or screws a quarter inch below the floor surface—any protruding nail heads will damage the sandpaper, which will then leave imperfections in the floor. Vacuum thoroughly, then spray the floor with hardwood cleaner or a solution of one part white vinegar in 10 parts water, and then gently and thoroughly wipe it down with a terry-cloth mop or a towel.

Finally, open windows and exterior doors for ventilation, and tape plastic sheeting over any interior doors or other openings to prevent dust from entering the rest of the house. Even if you keep interior doors closed, wedge towels underneath to keep dust from spreading through the gap.

Helpful Tip

When removing baseboard shoe molding, number each piece and its corresponding spot on the baseboard to make reinstallation easy.

1. Prep the Room

Correctly preparing the surface is just as important as what you put on it. Start by removing all contents of the room, including furniture, any floor-mounted HVAC grills, pipe collars around radiator supply lines, shoe molding (the strip of molding where the baseboard meets the floor), and any other obstructions.

Use painter’s tape or masking tape to protect baseboards from sanding equipment. Be sure to countersink any nails or screws a quarter inch below the floor surface—any protruding nail heads will damage the sandpaper, which will then leave imperfections in the floor. Vacuum thoroughly, then spray the floor with hardwood cleaner or a solution of one part white vinegar in 10 parts water, and then gently and thoroughly wipe it down with a terry-cloth mop or a towel.

Finally, open windows and exterior doors for ventilation, and tape plastic sheeting over any interior doors or other openings to prevent dust from entering the rest of the house. Even if you keep interior doors closed, wedge towels underneath to keep dust from spreading through the gap.

Helpful Tip

When removing baseboard shoe molding, number each piece and its corresponding spot on the baseboard to make reinstallation easy.

2. Sand the Perimeter

Starting with very fine sandpaper or screen (a mesh with embedded abrasive particles that is less aggressive than sandpaper), hand sand the perimeter of the room. You should sand out a good six inches from the baseboard to take care of any areas the buffer won’t be able to reach. (See the chart below for grit recommendations.) You want to be sure to sand in the same direction as the wood grain, going over each board until a powder forms from the finish you’ve removed.

2. Sand the Perimeter

Starting with very fine sandpaper or screen (a mesh with embedded abrasive particles that is less aggressive than sandpaper), hand sand the perimeter of the room. You should sand out a good six inches from the baseboard to take care of any areas the buffer won’t be able to reach. (See the chart below for grit recommendations.) You want to be sure to sand in the same direction as the wood grain, going over each board until a powder forms from the finish you’ve removed.

3. Buff or Scuff the Floor

The object of buffing, also called scuffing or screening, is to remove only a tiny fraction of the existing finish and create enough texture to allow a new coat of polyurethane to bond.

If you’ve never used a buffer before, you should practice on scrap wood or in the middle of the floor to get a feel for how to move the machine with control and constant motion. You want to be very careful not to cut through the finish into the color coat.

Using a maroon-colored buffing pad, a standard grit level designed to only remove the topcoat, guide the buffer across the floor in the same direction as the wood grain, overlapping each pass by six inches. The old finish will turn to powder, making it easy to see what areas you’ve already done. About every five minutes or so, you should stop to clean the pad with a vacuum.

Important
Safety Note

Sawdust is flammable and can spontaneously combust or even cause an explosion. To be safe, always empty the vacuum into a trash container outside of the home.

3. Buff or Scuff the Floor

The object of buffing, also called scuffing or screening, is to remove only a tiny fraction of the existing finish and create enough texture to allow a new coat of polyurethane to bond.

If you’ve never used a buffer before, you should practice on scrap wood or in the middle of the floor to get a feel for how to move the machine with control and constant motion. You want to be very careful not to cut through the finish into the color coat.

Using a maroon-colored buffing pad, a standard grit level designed to only remove the topcoat, guide the buffer across the floor in the same direction as the wood grain, overlapping each pass by six inches. The old finish will turn to powder, making it easy to see what areas you’ve already done. About every five minutes or so, you should stop to clean the pad with a vacuum.

Important
Safety Note

Sawdust is flammable and can spontaneously combust or even cause an explosion. To be safe, always empty the vacuum into a trash container outside of the home.

4. Clean and Tack the Floor

Don’t rush past this step: Nothing can undo all of your hard work on a hardwood floor like neglecting to clean it thoroughly before applying your coating. Once sanding is complete and the dust has settled, use a vacuum with a clean filter to thoroughly vacuum up all debris. Do one pass following the direction of the flooring, paying special attention to any gaps in the floorboards, then sweep across them at a 90-degree angle. Finally, use a microfiber mop, pushing with the grain, to dry tack the floor and remove any remaining dust.

4. Clean and Tack the Floor

Don’t rush past this step: Nothing can undo all of your hard work on a hardwood floor like neglecting to clean it thoroughly before applying your coating. Once sanding is complete and the dust has settled, use a vacuum with a clean filter to thoroughly vacuum up all debris. Do one pass following the direction of the flooring, paying special attention to any gaps in the floorboards, then sweep across them at a 90-degree angle. Finally, use a microfiber mop, pushing with the grain, to dry tack the floor and remove any remaining dust.

5. Apply the First Coat and Dry

Polyurethanes come in two types: oil-based and water-based. Although oil-based polyurethanes are typically less expensive, they produce more odor, take longer to dry, and present more cleanup challenges.

Before you start, be sure to cover your shoes with booties to avoid tracking debris on the floor, and use a respirator mask for protection.

Using a watering can to avoid drips, pour a four- to six-inch-wide stream of finish along the starting wall. Start by cutting in with a natural bristle brush along the wall. Then apply the coat to the open floor with the T-bar, holding it at a slight angle and snowplowing the finish up and down the entire floor with the grain.

Helpful Tip

Always maintain a wet edge to avoid lap marks.

5. Apply the First Coat and Dry

Polyurethanes come in two types: oil-based and water-based. Although oil-based polyurethanes are typically less expensive, they produce more odor, take longer to dry, and present more cleanup challenges.

Before you start, be sure to cover your shoes with booties to avoid tracking debris on the floor, and use a respirator mask for protection.

Using a watering can to avoid drips, pour a four- to six-inch-wide stream of finish along the starting wall. Start by cutting in with a natural bristle brush along the wall. Then apply the coat to the open floor with the T-bar, holding it at a slight angle and snowplowing the finish up and down the entire floor with the grain.

Helpful Tip

Always maintain a wet edge to avoid lap marks.

6. Apply the Second Coat and Dry

A second coat is usually recommended for durability, however, the wet film thickness of the first topcoat will affect the dry time and your ability to recoat. A normal recoat time is within three to four hours—any longer between topcoats will require additional sanding to get proper adhesion. After the second coat has dried, evaluate the consistency of the finish to see if it needs a third coat, but don’t apply more than two topcoats per day. Keep rugs and furniture off the floor for 15 days to fully cure. You can also paint wood floors if you want to transform the natural look of the wood.

6. Apply the Second Coat and Dry

A second coat is usually recommended for durability, however, the wet film thickness of the first topcoat will affect the dry time and your ability to recoat. A normal recoat time is within three to four hours—any longer between topcoats will require additional sanding to get proper adhesion. After the second coat has dried, evaluate the consistency of the finish to see if it needs a third coat, but don’t apply more than two topcoats per day. Keep rugs and furniture off the floor for 15 days to fully cure. You can also paint wood floors if you want to transform the natural look of the wood.

A beautiful light refinished hardwood floor in a home.

The Advanced Project:
How To Refinish a Hardwood Floor

The Advanced Project: How To Refinish a Hardwood Floor

A customer will likely want a projection of how long a more advanced job will take. Be very clear that this project will take a significant amount of time. A typical hardwood floor refinishing project will have at least four different sanding passes, each with a different type of sanding equipment: drum sander, rotary sander, orbital sander and, finally, an edger to get as close to the baseboard as possible. Additionally, furniture and rugs should not be returned to the room for up to 15 days to let the finish fully cure.

Full Floor Refinishing Supplies Checklist Tools and Materials:

Drum sander
checkmark icon

Rotary sander
checkmark icon

Orbital sander
checkmark icon

Edger

Sandpaper, various grits
checkmark icon

Hand sander

Scraper

Vacuum

Buffer

Maroon buffing pad
checkmark icon

Screen

T-bar and coater

Natural bristle brush
checkmark icon

Rags

Finish stain
checkmark icon

Polyurethane topcoat
checkmark icon

Watering can
checkmark icon

Painter's tape

Googles or glasses
checkmark icon

Respirator mask
checkmark icon

Ear plugs

Kneepads

Full Floor Refinishing
Supplies Checklist Tools and Materials:

Drum sander
checkmark icon

Rotary sander
checkmark icon

Orbital sander
checkmark icon

Edger

Sandpaper, various grits
checkmark icon

Hand sander
checkmark icon

Scraper

Vacuum

Buffer

Maroon buffing pad
checkmark icon

Screen

T-bar and coater
checkmark icon

Natural bristle brush
checkmark icon

Rags

Finish stain
checkmark icon

Polyurethane topcoat
checkmark icon

Watering can
checkmark icon

Painter's tape
checkmark icon

Googles or glasses
checkmark icon

Respirator mask
checkmark icon

Ear plugs

Kneepads

1. Prep the Room

As with the simple recoating, you need to start by emptying everything from the room, including furniture, floor-mounted HVAC grills, pipe collars, and any other obstructions like shoe molding. You then need to tape off baseboards and countersink all nails and screws, carefully vacuum and mop with hardwood cleaner, open windows for ventilation, and tape plastic over interior doors to control dust.

1. Prep the Room

As with the simple recoating, you need to start by emptying everything from the room, including furniture, floor-mounted HVAC grills, pipe collars, and any other obstructions like shoe molding. You then need to tape off baseboards and countersink all nails and screws, carefully vacuum and mop with hardwood cleaner, open windows for ventilation, and tape plastic over interior doors to control dust.

2. Rough Cut with a Drum Sander

A drum sander is a powerful, labor-saving piece of machinery that can easily remove cupping and crowning—but can also do a significant amount of damage to a floor if you don’t know how to properly use it. Start by installing 36-grit sandpaper on the drum sander and testing it first on a scrap piece of plywood to get comfortable with its operation before you try it on real floorboards.

When you’re ready to try it on the real floor, start in the middle of the longest wall, about six inches out from the baseboard. Make sure the drum sander is in the raised position when you start it, then carefully lower the drum as you move forward. Keeping the machine in constant motion, sand in a straight line following the direction of the grain, until you reach a point about one foot from the far wall. Raise the drum as you stop, then move it over to do a return pass with minimal overlap. As you do successive passes, try to stagger your ending points so you don’t create a sanding pattern, and replace the sandpaper as needed. Once the room is fully sanded, vacuum thoroughly before the next step.

Helpful Tip

Sanding across the wood’s grain can cause splintering or shedding—but it might be necessary to remove damage from water or pet stains. Just be sure to always sand with the grain on your final pass.

2. Rough Cut with a Drum Sander

A drum sander is a powerful, labor-saving piece of machinery that can easily remove cupping and crowning—but can also do a significant amount of damage to a floor if you don’t know how to properly use it. Start by installing 36-grit sandpaper on the drum sander and testing it first on a scrap piece of plywood to get comfortable with its operation before you try it on real floorboards.

When you’re ready to try it on the real floor, start in the middle of the longest wall, about six inches out from the baseboard. Make sure the drum sander is in the raised position when you start it, then carefully lower the drum as you move forward. Keeping the machine in constant motion, sand in a straight line following the direction of the grain, until you reach a point about one foot from the far wall. Raise the drum as you stop, then move it over to do a return pass with minimal overlap. As you do successive passes, try to stagger your ending points so you don’t create a sanding pattern, and replace the sandpaper as needed. Once the room is fully sanded, vacuum thoroughly before the next step.

Helpful Tip

Sanding across the wood’s grain can cause splintering or shedding—but it might be necessary to remove damage from water or pet stains. Just be sure to always sand with the grain on your final pass.

3. Sand the Perimeter with an Edger

The edger will let you get as close as possible to the wall, typically covering the last two to three inches of floor. Use the same grit sandpaper as you used with the drum sander in Step 2. Make sure to start the edger with it tilted onto its back caster or wheel, so the sandpaper isn’t touching the floor, then slowly lower it to bring the paper in contact with the floor surface. Any direction is fine, just be sure to keep the edger moving as you work your way around the border areas of the floor.

At first, try letting the weight of the edger be the only pressure; if that isn’t enough, maintain steady, light pressure and avoid pushing down with your weight on the sander. When you’ve sanded all along the perimeter of the room, tilt back the sander so the paper isn’t in contact with the floor before switching off the machine.

The edger creates a round sanding pattern, so you will still need to use a sharp paint scraper or hand sander to touch up any hard-to-reach areas along the edge of the room that the sanders couldn’t reach.

Helpful Tip

Drape the edger power cord over your shoulder. This will not only prevent you from running it over with the sander, it will let you keep precise control with both hands on the handles of the edger.

3. Sand the Perimeter with an Edger

The edger will let you get as close as possible to the wall, typically covering the last two to three inches of floor. Use the same grit sandpaper as you used with the drum sander in Step 2. Make sure to start the edger with it tilted onto its back caster or wheel, so the sandpaper isn’t touching the floor, then slowly lower it to bring the paper in contact with the floor surface. Any direction is fine, just be sure to keep the edger moving as you work your way around the border areas of the floor.

At first, try letting the weight of the edger be the only pressure; if that isn’t enough, maintain steady, light pressure and avoid pushing down with your weight on the sander. When you’ve sanded all along the perimeter of the room, tilt back the sander so the paper isn’t in contact with the floor before switching off the machine.

The edger creates a round sanding pattern, so you will still need to use a sharp paint scraper or hand sander to touch up any hard-to-reach areas along the edge of the room that the sanders couldn’t reach.

Helpful Tip

Drape the edger power cord over your shoulder. This will not only prevent you from running it over with the sander, it will let you keep precise control with both hands on the handles of the edger.

4. Medium Cut with a Rotary Sander

Many pros will only use a drum sander throughout a floor refinishing project, however using a few more specialized tools like an orbital or rotary sander will give you more reliable results. As with the drum sander, if you are not already comfortable with the rotary sander and the amount of torque it can produce, you should first test it out on scrap lumber. Although not as powerful as a drum sander, a rotary sander is also useful for flattening wood, only slower and with more precision. Movement is controlled by the slightest up or down tilt on the sander’s handle.

You are using this sander to provide a more precise cut, so you also want to upgrade your sandpaper to a finer grit—see the chart below for recommended grit levels. As with Step 3, you want to start halfway down the wall and move with the grain of the wood to the end of the wall, then do a return pass with minimal overlap. Repeat in parallel passes until the room is complete.

At this stage, you should again use the edger, with the same grit level of sandpaper you just used with the rotary sander, to also do a medium cut for the perimeter. Then you can touch up corners with a scraper or hand sander. Once this is done, carefully vacuum up all debris.

4. Medium Cut with a Rotary Sander

Many pros will only use a drum sander throughout a floor refinishing project, however using a few more specialized tools like an orbital or rotary sander will give you more reliable results. As with the drum sander, if you are not already comfortable with the rotary sander and the amount of torque it can produce, you should first test it out on scrap lumber. Although not as powerful as a drum sander, a rotary sander is also useful for flattening wood, only slower and with more precision. Movement is controlled by the slightest up or down tilt on the sander’s handle.

You are using this sander to provide a more precise cut, so you also want to upgrade your sandpaper to a finer grit—see the chart below for recommended grit levels. As with Step 3, you want to start halfway down the wall and move with the grain of the wood to the end of the wall, then do a return pass with minimal overlap. Repeat in parallel passes until the room is complete.

At this stage, you should again use the edger, with the same grit level of sandpaper you just used with the rotary sander, to also do a medium cut for the perimeter. Then you can touch up corners with a scraper or hand sander. Once this is done, carefully vacuum up all debris.

5. Fine Cut with an Orbital Sander

Orbital sanders (sometimes called jitterbug sanders) let you get closer to the edge of the wall with much finer control, so they have less of a chance of damaging the floor than a drum sander. As such, they are the easiest sander to use; they are also very slow. This makes it a perfect tool to use with a finer grit sandpaper to blend different scratch patterns from your previous sanding steps, which will prevent leaving a hat banding pattern with a different finish around the edges of the room.

One advantage of an orbital sander is that you don’t have to sand with the grain, so you can work your way around different floor areas in succession. Be sure to replace the sandpaper as it becomes worn down or clogged. As with the previous steps in your sanding sequence, once the room is done, be sure to carefully vacuum up all debris before moving to the next step.

5. Fine Cut with an Orbital Sander

Orbital sanders (sometimes called jitterbug sanders) let you get closer to the edge of the wall with much finer control, so they have less of a chance of damaging the floor than a drum sander. As such, they are the easiest sander to use; they are also very slow. This makes it a perfect tool to use with a finer grit sandpaper to blend different scratch patterns from your previous sanding steps, which will prevent leaving a hat banding pattern with a different finish around the edges of the room.

One advantage of an orbital sander is that you don’t have to sand with the grain, so you can work your way around different floor areas in succession. Be sure to replace the sandpaper as it becomes worn down or clogged. As with the previous steps in your sanding sequence, once the room is done, be sure to carefully vacuum up all debris before moving to the next step.

6. Final Cut with an Orbital Sander

For this precision sanding step, you want to use the same orbital sander as you did in Step 5, but with a finer sandpaper to feather out any remaining ridges or uneven areas. Be sure to look for borders between where different sanders were used, and spend extra time sanding those areas to blend them, if necessary.

6. Final Cut with an Orbital Sander

For this precision sanding step, you want to use the same orbital sander as you did in Step 5, but with a finer sandpaper to feather out any remaining ridges or uneven areas. Be sure to look for borders between where different sanders were used, and spend extra time sanding those areas to blend them, if necessary.

7. Clean and Tack the Floor

As with the basic project, skipping this step can trap dust and debris in your finish, undoing all of your hard work. Now that all the sanding is complete, use a vacuum with a clean filter to thoroughly vacuum up all dust and debris. Do one pass following the direction of the flooring, then sweep across the floorboards at a 90-degree angle to remove all dust from between the planks. Finally, dry tack the floor with a microfiber mop, pushing with the grain, to remove any remaining dust.

7. Clean and Tack the Floor

As with the basic project, skipping this step can trap dust and debris in your finish, undoing all of your hard work. Now that all the sanding is complete, use a vacuum with a clean filter to thoroughly vacuum up all dust and debris. Do one pass following the direction of the flooring, then sweep across the floorboards at a 90-degree angle to remove all dust from between the planks. Finally, dry tack the floor with a microfiber mop, pushing with the grain, to remove any remaining dust.

8. Stain the Floor

Once the floor is clean and dry, you can now apply your customer’s stain color of choice. Starting at one side of the room, use a rag or sponge to carefully spread the stain over the wood a few boards at a time, working with the grain. As you work your way across the room, wring out the rag or sponge frequently to prevent the stain from pooling on the floor and to keep coverage even. After the stain has been on the wood for five or 10 minutes, use a clean rag to wipe up any excess stain—the length of time the stain soaks into wood will determine how dark the finished floor ends up.

8. Stain the Floor

Once the floor is clean and dry, you can now apply your customer’s stain color of choice. Starting at one side of the room, use a rag or sponge to carefully spread the stain over the wood a few boards at a time, working with the grain. As you work your way across the room, wring out the rag or sponge frequently to prevent the stain from pooling on the floor and to keep coverage even. After the stain has been on the wood for five or 10 minutes, use a clean rag to wipe up any excess stain—the length of time the stain soaks into wood will determine how dark the finished floor ends up.

9. Apply the First Clear Coat

Once the stain is dry, it’s time to apply the first coat of polyurethane as outlined in the above section. Be sure to cover your shoes with booties, and use a respirator mask for protection.

Pour a four- to six-inch-wide stream of finish along the starting wall with a watering can, then cut in with a natural bristle brush along the wall. Use a T-bar to apply the coat to the open floor, snowplowing the finish up and down the entire floor with the grain until the surface is covered. Allow to dry for three to four hours, keeping in mind that your exact drying time will be determined by humidity and the thickness of your first coat.

9. Apply the First Clear Coat

Once the stain is dry, it’s time to apply the first coat of polyurethane as outlined in the above section. Be sure to cover your shoes with booties, and use a respirator mask for protection. If you’re using the preferred Lenmar^® ClearCoat PRO, shake the can thoroughly and let it rest for 15 minutes to allow bubbles to break before use. Pour a four- to six-inch-wide stream of finish along the starting wall with a watering can, then cut in with a natural bristle brush along the wall. Use a T-bar to apply the coat to the open floor, snowplowing the finish up and down the entire floor with the grain until the surface is covered. Allow to dry for three to four hours, keeping in mind that your exact drying time will be determined by humidity and the thickness of your first coat.

10. Buff and Clean

To ensure the second coat of polyurethane will bond fully, you should use a buffer with a maroon buffing pad (equivalent to a 320-grit abrasive) to gently scuff the first coat. Keeping the buffer in constant motion, guide it across the floor in the same direction as the wood grain, overlapping each pass by six inches. Every five minutes or so, stop to clean the pad with a vacuum.

10. Buff and Clean

To ensure the second coat of polyurethane will bond fully, you should use a buffer with a maroon buffing pad (equivalent to a 320-grit abrasive) to gently scuff the first coat. Keeping the buffer in constant motion, guide it across the floor in the same direction as the wood grain, overlapping each pass by six inches. Every five minutes or so, stop to clean the pad with a vacuum.

11. Apply a Second Clear Coat

Apply a second coat in the same manner as the first, beginning with cutting in along the wall with a brush and then using a T-bar to spread polyurethane throughout the rest of the room. After the second coat has dried—typically three to four hours—evaluate the floor to make sure the finish is even and see if it needs a third coat, but don’t apply more than two topcoats per day. Keep rugs and furniture off the floor for 15 days to allow the floor to fully cure.

11. Apply a Second Clear Coat

Apply a second coat in the same manner as the first, beginning with cutting in along the wall with a brush and then using a T-bar to spread polyurethane throughout the rest of the room. After the second coat has dried—typically three to four hours—evaluate the floor to make sure the finish is even and see if it needs a third coat, but don’t apply more than two topcoats per day. Keep rugs and furniture off the floor for 15 days to allow the floor to fully cure.

A beautiful dark refinished living room floor.

Match Your Sandpaper Grit to the Steps of the Project

The more damaged the floor and harder the wood, the coarser your first grit pass should be. When refinishing a wood floor, the sandpaper grit can range between 12 and 120, so it’s important to find the optimal level to strike the right balance between productivity and precision. With sandpaper, the coarser or lower the grit, the more productive the sanding. You want to avoid leaving deep cuts in the floor that can pool stain or leave unsightly inconsistencies in your clear coat.

When in doubt about where to start, use 36-grit on an area that has the most visible damage to see if it will give you a clean, bare floor with no signs of previous finish or imperfections. As a general rule, you want to use the finest grit that will get the job done—if the sandpaper is clogging or leaving a lot of finish behind, move to a coarser grit. Try not to skip more than two grit sizes in your sequence. This chart gives an ideal breakdown of grit sizes through the steps of a project.

Sanding step:	Grit:

Rough Cut with Drum Sander	36

Rough Cut with Edger	36

Medium Cut with Rotary Sander	50

Medium Cut with Edger	50

Corners by Hand	50

Fine Cut with Orbital Sander	80

Final Cut with Orbital Sander	100

Buffer	120

Match Your Sandpaper Grit to the Steps of the Project

The more damaged the floor and harder the wood, the coarser your first grit pass should be. When refinishing a wood floor, the sandpaper grit can range between 12 and 120, so it’s important to find the optimal level to strike the right balance between productivity and precision. With sandpaper, the coarser or lower the grit, the more productive the sanding. You want to avoid leaving deep cuts in the floor that can pool stain or leave unsightly inconsistencies in your clear coat.

When in doubt about where to start, use 36-grit on an area that has the most visible damage to see if it will give you a clean, bare floor with no signs of previous finish or imperfections. As a general rule, you want to use the finest grit that will get the job done—if the sandpaper is clogging or leaving a lot of finish behind, move to a coarser grit. Try not to skip more than two grit sizes in your sequence. This chart gives an ideal breakdown of grit sizes through the steps of a project.

Sanding step:	Grit:

Rough Cut with Drum Sander	36

Rough Cut with Edger	36

Medium Cut with Rotary Sander	50

Medium Cut with Edger	50

Corners by Hand	50

Fine Cut with Orbital Sander	80

Final Cut with Orbital Sander	100

Buffer	120

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Stays Clear®

Get a durable, non-yellowing finish for your final finish coat.

See Details

Top Interior Add-Ons for Customers

Offer your customers these add-ons while you’re on the job site.

Benefits of a Bonding Primer

See why bonding primer reduces time and effort on the job.

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Stays Clear®

Get a durable, non-yellowing finish for your final finish coat.

See Details

Top Interior Add-Ons for Customers

Offer your customers these add-ons while you’re on the job site.

Benefits of a Bonding Primer

See why bonding primer reduces time and effort on the job.

Get Advice

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A Pro's Guide to Refinishing Hardwood Floors

A Pro's Guide to Refinishing Hardwood Floors

Important Safety Note

Important Safety Note

The Basic Project: How To Screen and Recoat a Hardwood Floor

The Basic Project: How To Screen and Recoat a Hardwood Floor

Basic Refinishing Supplies Checklist

Basic Refinishing Supplies Checklist

1. Prep the Room

Helpful Tip

1. Prep the Room

Helpful Tip

2. Sand the Perimeter

2. Sand the Perimeter

3. Buff or Scuff the Floor

Important Safety Note

3. Buff or Scuff the Floor

Important Safety Note

4. Clean and Tack the Floor

4. Clean and Tack the Floor

5. Apply the First Coat and Dry

Helpful Tip

5. Apply the First Coat and Dry

Helpful Tip

6. Apply the Second Coat and Dry

6. Apply the Second Coat and Dry

The Advanced Project: How To Refinish a Hardwood Floor

The Advanced Project: How To Refinish a Hardwood Floor

Full Floor Refinishing Supplies Checklist Tools and Materials:

Full Floor Refinishing Supplies Checklist Tools and Materials:

1. Prep the Room

1. Prep the Room

2. Rough Cut with a Drum Sander

Helpful Tip

2. Rough Cut with a Drum Sander

Helpful Tip

3. Sand the Perimeter with an Edger

Helpful Tip

3. Sand the Perimeter with an Edger

Helpful Tip

4. Medium Cut with a Rotary Sander

4. Medium Cut with a Rotary Sander

5. Fine Cut with an Orbital Sander

5. Fine Cut with an Orbital Sander

6. Final Cut with an Orbital Sander

6. Final Cut with an Orbital Sander

7. Clean and Tack the Floor

7. Clean and Tack the Floor

8. Stain the Floor

8. Stain the Floor

9. Apply the First Clear Coat

9. Apply the First Clear Coat

10. Buff and Clean

10. Buff and Clean

11. Apply a Second Clear Coat

11. Apply a Second Clear Coat

Stays Clear®

Top Interior Add-Ons for Customers

Benefits of a Bonding Primer

Stays Clear®

Top Interior Add-Ons for Customers

Benefits of a Bonding Primer

Stays Clear®

Top Interior Add-Ons for Customers

Benefits of a Bonding Primer

Looking for more business info?

A Pro's Guide to Refinishing
Hardwood Floors

Important
Safety Note

Important
Safety Note

The Basic Project:
How To Screen and Recoat
a Hardwood Floor

The Basic Project:
How To Screen and Recoat a Hardwood Floor

Basic Refinishing
Supplies Checklist

Important
Safety Note

Important
Safety Note

The Advanced Project:
How To Refinish a Hardwood Floor

Full Floor Refinishing
Supplies Checklist Tools and Materials: