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How do you Sand and Refinish a Hardwood Floor?

A hardwood floor gives a classic feel to your home. It looks beautiful and adds an elegant appeal to your living space. As all the beauty in this world, whether natural or man-made, needs adequate maintenance, so do these hardwood floors. You need to take care of this vulnerable yet stylish floor to keep it attractive for years to come.

Bare wood exposure of your floor is susceptible to decay and warping caused by water or moisture. This can happen when a liquid spills or when cleaning a wooden floor with water-based methods. It is essential to protect the natural material with multiple coats of sealant.

Most home-owners spend thousands of dollars on refinishing and re-coating their hardwood floor to prevent it from any damage and decay. A re-coating involves the addition of a protective finish layer over the existing layer of hardwood floor. A refinish, however, includes sanding and adding multiple layers of coat.

How to Sand a Hardwood Floor

Sanding the hardwood floor requires numerous steps. But before performing sanding, you need to prepare your floor for the process.

Step 1: Preparing your floor

  • Keep all the furniture in some other room to clear the floor completely for the process.
  • Remove your floor carpet, if any.
  • Remove all the gripper rods that held your carpet in place.
  • Hammer all the nails you find in your hardwood floor 2mm deep into the surface to avoid tearing of your sandpaper.
  • Don’t forget to check for nail heads and bits of grit stuck in the joints.
  • Sweep and vacuum the hardwood floor and mop it with a damp cloth to ensure cleanliness before the process.
  • Wear eye protection and a face mask to prevent inhalation of dust particles.
  • Wear ear protection to protect yourself from the noise produced during sanding.
  • Also wear gloves to avoid any injuries from splinters and other harmful objects.
  • Determine the grit sequence your floor requires. An old floor with multiple holes that have not been sanded for 25+ years might need coarser 24grit sequence whereas a 36grit sequence would suffice a newly installed floor.

Step 2: Sanding process

  1. Sand all over your hardwood floor with the help of drum sander. For achieving professional results, 4 sanding passes are a must. You are also required to follow a sequence to get a smooth floor. So, if you start with a 24 grit pass, your sequence would look like 24 > 36 > 60 > 80grit. You cannot start the sanding process with a 60 or 80grit pass, as they are used only for smoothing out the surfaces. Though 80grit is a final pass for most American hardwood floors, you can go for a 100grit too for the best results. Finish the whole area you are planning to sand before proceeding to the next step.
  2. The drum sander won’t reach the edges of your room. You would require an edger to do sanding jobs in the areas where drum couldn’t reach. The edger can sand out the drum marks which are left while transitioning through the walls, so you must edge after drumming. Use the same grit on the edger that you used for the whole area. Finish up all the rooms on which you used drum sander.
  3. Vacuum and sweep all the sanded rooms before continuing with the next grit session.
  4. Once you have removed all the debris from the previous grit sanding, start with sanding your hardwood floor with the next finer grit as per your determined grit sequence.
  5. Follow sanding at the corners of the room with an edger with the grit used in 4th step and clear all the debris again before proceeding for the next grit in the sequence.
  6. Continue this process following your determined grit sequence till you get the desired results. You can stop either at 80grit or perform a 100grit pass for even better results.

Useful tips

  • Use wood sander parallel to the ground for avoiding excess shredding of wood off-grain.
  • For extremely old floors that are severely scarred and uneven, consider using the wood sander at a rough angle of 10-20 degrees off parallel. It will scrape off more wood and speed up your sanding process.
  • If you have the opportunity to involve another person in the process, do not perform drum sanding and edger simultaneously in the same room. Edger will help in removing any visible effects of drumming near the walls. Also, you don’t want your electric wires to mingle resulting in a hazard.
  • Never try to jump your grit sequence. Follow it on both the machines or else you might get ugly results.
  • If you perform an angular pass, follow with a parallel pass with the same grit and continue with your sequence thereafter. So, if you performed 36grit angular pass, your sanding sequence would be 36 angular > 36 parallel > 60 > 80 > 100.
  • If you find that the perimeter of a room has more finish and require more sanding, use the next coarser grit on the edger for speeding up the process. Move quickly over the perimeter’s surface for removing about half of the finish. Continue sanding the remaining finish with the grit you used on your drum sander. 

How to Refinish Hardwood Floors

Once you are done with the sanding process, it is time to refinish your hardwood floor and make it beautiful. You can also do away with the sanding process if your floor is in good condition and only seems to require a new look due to some stains here and there. The unsightly scratches and marks can also be removed with a new coating over the old finish.

Step 1: Preparing your floor

  • Preparation of your hardwood floor is essential to get the desired results. If you haven’t followed the above-mentioned sanding process because your floor doesn’t require it, you need to take a few steps before carrying on with the process of refinishing:
  • Clear up your floor completely and clean it with a vacuum.
  • Find the problem areas of your floor and evaluate them with your hands. This will help you know whether you need to sand the area or a re-coating will suffice.
  • Sand the areas with deep scratches for an even surface.
  • Roughen the old finish with sanding screens to ensure that the new finish sticks well to the floor. You can also use the walk-behind floor sander for the free surface and a hand-held power edge sander for sanding against the walls and corners. These are available for rent on a daily basis.
  • Even up the surface to the best you can. It will ensure an even coating and deliver better results.
  • Clean up the sanding dust with a vacuum. Mop the floor with a damp cloth to remove all debris properly.

Your floor is now ready to get a new finish of your choice.

Choice of finishes you have for a hardwood floor

The type of finish you choose for your hardwood floor depends largely on the final outcome you desire to have. The look you have in your mind will play a major role in choosing one type over the other. The other important factor for consideration is the durability that a finish offers.

Polyurethane – These are the most commonly used finishes due to the ease of application they offer. Other finishes are relatively difficult to work with for a DIYer.

Polyurethane offers versatile looks. You can get a polyurethane coating in various degrees of luster. You further got an option to choose between a water-based or oil-based coat keeping in mind the following factors:

  1. The oil-based are easier to work with as they dry slowly. You get more time to smooth out the finish before it dries. With water-based finish, you need to work quickly as it dries up faster.
  2. While working with oil-based finish, nasty vapor is released, so you need to wear a respirator before carrying on with this process. A water-based finish, however, does not pose any such issue.
  3. The oil-based finish will give a yellowish-hue to your floor that will darken slowly with time. Water-based polyurethanes have a milky color when you apply the finish and becomes crystal clear when the coating dries up. It remains clear over time. You’re less likely to miss the spots when working with the water-based finish due to the clear visibility in the form of milky color while application.

Depending on the look you desire, you can choose between these subtypes. Polyurethane finishes works extremely well with both high-traffic and high-moisture areas. It is, however, difficult to repair a spot that gets nicked accidentally.

Sealer – If you are on the lookout for a finish that can easily be spot-repaired, look no further. Penetrating sealer can be applied again on the unsightly spot to give a new look to your wood floor again. These sealers delivers a natural look to your hardwood floor by bringing out the wood’s grain. This finish, however, darkens with time. You can expect a good protection of your wood floor with a penetrating sealer, especially when waxed. One drawback of this finish is its durability. It is much less durable than polyurethane.

Varnish – If you are planning to give a glossy look to your hardwood floor, choose a varnish finish over others. Varnish also delivers a matte finish but it is less durable than the glossy one. With an increase in gloss, durability also increases. Like sealer, varnish also darkens over time. You can also carry-out spot-repairs with this kind of finish. Varnish is more durable than penetrating sealer.

Step 2: Refinishing process

  1. After cleaning up the dirt and debris from touch-up sanding or a full sanding process, apply the first coat of your preferred finish.
  2. For drying time between coats, stick with the directions mentioned on the finish container.
  3. Apply the second coat after the first one dries up completely.
  4. Follow with the third and fourth coats in the same manner.
  5. Move your furniture to the room after waiting for at least 48 hours to allow drying up of the final coat properly.

Useful tips

  • Do not forget to wipe clean the hardwood floor with a damp lint-free cloth after vacuum. When dust particles combine with the wet coating, tiny craters or bumps are formed, giving an ugly look to your floor. Also, ensure that the cloth used in cleaning has not been washed with fabric softener as in that case the finishing coat won’t adhere to the floor properly.
  • Use a high-quality brush to apply the coating. A good paint-brush ensures an even coating all over the surface. Apply the brush strokes in the direction of your floor’s wood grain.
  • If you experience any nasty odor from the finish paint, open all the windows to allow the dispersal of smell and wear a respirator to prevent direct inhalation.
  • While choosing a finish, consider the maneuverability of all the options you have. Working with a difficult finish to get a particular look for your wood might backfire. When you are spending your whole weekend and investing your hard-earned money on renting out the home-improvement equipment, your primary goal should be achieving the error-free look. Achieving an even look with correctly-done polyurethane is way better than getting a patchy floor with incorrectly-done varnish.   
  • To avoid your hardwood floor from holding moisture, refinish it the very same day you sand it. Open wood surface is more susceptible to damage, so you need to finish up the whole process as quickly as you can.
  • Apply the finish coating evenly throughout the floor using it enough to cover the surface. Applying excess coating will result in ugly spots as it will pool on the surface.
  • Clean the floor again after your first finish coat dries up. Avoid the use of damp cloth this time, only use vacuum to clear up the dust.
  • Do not try to reapply the finish on an ‘uneven coating spot’ as it will only further the unevenness. You can cover that spot later in your next coating session.
  • Do not forget to follow the wait-time mentioned on the finish container before applying the next coating. Beautiful things take time in their formation.
  • For normal traffic areas, three coats will suffice while a fourth coat is required for high-traffic areas like hallways.

Frequently Asked Questions

Here are answers to commonly asked questions about sanding and refinishing a hardwwood floor:

How long does it take to Refinish Hardwood Floors?

A complete sanding of a 10m² room can take around 5 to 6 hours if you are doing it for the first time. If you are just touching up your hardwood floor, it will take only an hour or two. A professional floor sander, however, can perform the same task in under an hour.

Refinishing is much less time-consuming than sanding. Even if you are doing it for the first time, you’ll be able to finish the same sized room in under an hour. Multiply this time with three or four depending upon the number of coats you are planning for the room. Also, consider the wait-time for the type of finish you are using. The total time spent on the process will depend on that too.

How much does it Cost to Refinish Hardwood Floor yourself?

The cost of refinishing varies from state to state. A professional will charge anywhere between $9 to $25 per square foot. But if you ‘Do It Yourself’, you can save a huge amount. You can expect to complete the whole job spending $2 to $12 per square feet by carrying it out on your own.

You will have to arrange for a drum floor sander and an edge sander from a home improvement store. Hire them for a day or a weekend depending on the area you are aiming to revamp. You will be charged anywhere between $20 to $80 as day’s rent. The cost varies considerably from state to state. Also, bargaining with your local hardware stores can help you avail great discounts.

You will also need to purchase sanding sheets for both the machines. The cost of these sheets depends on the area you are planning to cover. More coverage area means more costs involved.

Protecting yourself from inhaling dust should be your priority while performing the job. Dust masks can be purchased spending only a few bucks.

A finish might cost you between $30 to $60, again depending on your state along with the choice of finish you make. If you are planning for multiple coats or a large area, your finish cost will increase.

Precautions:

  • If your floor is made of an exotic wood, it is better to leave the refinishing job to a professional. These woods are very difficult to work with and require expert-level care for handling as their dust is injurious to health.
  • If the quality of the previous finish of your hardwood floor is superior, your refinishing costs tend to be lower. On the other hand, if you judged the quality wrong, you might have to bear the additional cost of sanding and refinishing instead of just a re-coat. In short, the quality of the previous finish of your wood floor is a major deciding factor in determining your refinish cost.
  • Refinishing stairs is tough and generally costs between $20 to $50 per step when outsourced. It is because carrying the machines over stairs is a difficult job. Moreover, some twists and turns poses a problem in creating a smooth surface. If you are not sure that you can carry out the sanding job well over your stairs, it is better to call an expert for the job. Else, you might end up bearing a cost yourself and then calling an expert to repair the mess you created.

Which is Cheaper, to Refinish or Replace Hardwood Floors?

For determining whether refinishing is cheaper for you or replacing the hardwood floor, we need to consider the situation of your wood floor.

In case of lightly-worn hardwood floor

If your hardwood floor has a few scratches here and there and some discoloration issue, your hardwood floor does not require a complete sanding process. You can touch-up areas where scratches are prevalent with a hand sander. You do not even need to hire costly sanding machines since your floor can be fixed without them. Just get a hand sander and 80 grit sheets to smooth out the lightly-worn surface.

After finishing up with touch-up sanding, you can continue with the refinish process. Replacement of hardwood floor is not required at all in such a case. If you find one or two holes in your floor while sanding, you can always replace those blocks with new ones.

Therefore, in the case of lightly-worn hardwood floor refinishing is cheaper than replacement of the floor.

In case of thick but worn-out hardwood floor

If your hardwood floor is very old and worn-out but is thick enough to carry out the sanding process, you should not consider a complete replacement. Your wood floor still carries the potential to be treated upon and renewed. Follow the sanding and refinishing process as described above and your floor will have all the new looks.

Carrying out a replacement procedure in this scenario would cost you much more than sanding. It is because you will be required to replace all of your wood blocks as these are very old. And replacing only a few of them here and there will make them stand out from the rest even after refinish.

In short, an extremely worn-out hardwood floor which still has sufficient thickness, shall be treated with sanding. Replacing the hardwood floor would be a costly affair for you.

In case of thin hardwood floor

Refinish is for you if your wood can be processed. If you have carried out sanding multiple times before, consider checking the thickness of your hardwood floor. Also, the thickness of modern-day polished wood floors is quite less. In such cases, it is advised not to perform sanding and refinishing as it will compromise with the strength of your floor. Your floor might also develop holes soon as there is not much volume left in it. With time, it will become a costly affair for you since you will again have to spend money on getting it repaired.

Replacing the hardwood floor is a great option in such cases. Invest in a complete overhaul of your floor and you will remain tension-free for decades to come. In other words, replacement will be a cheaper option for you, considering the long-term impact.

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