How To Varnish Stairs: A Step-By-Step Guide

Are you planning on varnishing your stairs? If so, then there are sure to be things you do not know, such as which varnish is the best to use, which temperature is the best to varnish in, and how to properly prepare your stairs. Below, all of your questions are sure to be answered in this step-by-step complete guide.

To varnish your stairs, purchase new materials, stir the varnish, set the temperature to 70 degrees, remove any pre-existing carpeting, sand down the stairs, clean up the stairs, thin the varnish, thinly apply the varnish, and allow the varnish to set.

Varnishing your stairs does not have to be a difficult task. By following the steps below, the process will be much simpler and a quality result will be guaranteed.

1. Purchase New Materials

The first step to successfully varnish your stairs is to purchase all new materials. Purchasing new materials will allow for a cleaner finish, and will inhibit visible and preventable mistakes. Do not use the materials that you have had for years simply for convenience.

Below is a list of the materials that you will need to purchase in order to varnish your stairs:

  • Polyurethane varnish
  • Wide foam brush
  • Stirring stick
  • Paint tray

Polyurethane varnish is commonly used for stairs. This varnish is durable and will protect your hardwood flooring. Polyurethane varnish is oil-based and therefore is not sensitive to the wear and tear of everyday life. This varnish is resilient and is the reason it is used for stairs.

Although this varnish can last an exceptional amount of time, it is recommended to purchase a new varnish. Use a brand new varnish in order to avoid the possibility of lumps appearing after you have finished varnishing your stairs.

In addition to purchasing a new polyurethane varnish, remember to purchase a new brush. When varnishing stairs, a wide foam brush will be needed. Do not use an old, pre-used brush. This may compromise the results of your varnishing when it could be easily avoided. Your brush will greatly impact the overall results of your stairs, so it is important to not settle for the first option you may have available.

2. Stir The Varnish

The second step includes stirring the varnish and pouring out enough of the varnish for your first layer. Remember to never shake your varnish. Instead, stir it gently. Shaking your varnish will cause bubbles that could have otherwise been avoided.

To stir your varnish, use a newly purchased stirring stick that is commonly used for paint. After the varnish has been gently stirred, pour the varnish out into a tray. You should pour out just enough varnish that will be needed for one layer. Repeat this step for every additional layer of varnish.

3. Set The Temperature to 70 Degrees

The third step is setting the temperature. Believe it or not, the temperature you varnish your stairs in is very important. Varnishing your stairs at the correct temperature allows for quality results. When you varnish your stairs, you will want to set the thermostat to seventy to seventy-five degrees Fahrenheit, or twenty-one to twenty-four degrees Celcius.

If the temperature is too cold, then the varnish will dry slowly. If the varnish dries slowly, then there is an increased chance that dust will appear in the finality of your project. Imperfections will be more prevalent within colder temperatures.

When the temperature is too cold, the varnishing process is forced to be extended because of how slowly it will dry. Although you do not want to rush the process, there is no reason to make the process slower than it needs to be.

If the temperature is too warm, the varnish will dry quicker than it is supposed to, which may cause unnecessary imperfections to its finish. The solvent within the varnish may evaporate quicker than expected which causes messy results.

4. Remove Any Carpeting

The fourth step is to remove any carpeting from your stairs. If your stairs happen to have carpeting, then they will need to be removed before varnishing.

Below is a guide to removing the carpeting from your stairs, using just five simple steps!

  1. If there is carpet on the floor above the top stair, cut the carpet under the nose of the top stair using a utility knife. The nose is the lip that extends out over the riser.
  2. Using the locking pliers and the utility knife, cut the carpet into manageable sections and pull the carpet free of the riser. Continue across the riser until all of the carpeting has been removed.
  3. If the carpet padding is tacked on, simply pull it up and dispose of it in a contractor bag. If the carpet padding is glued down, use a putty knife to scrape the glue and carpet padding off the stairs.
  4. Slide a putty knife under the tack strip to help protect the stair, then place the edge of a pry bar on top of the putty knife and under the edge of the tack strip.
  5. Use a hammer to tap the pry bar under the tack strip, then pry the tack strip away. Proceed along the entire strip until it lifts away from the stair. Carefully place the tack strip and any pieces or tacks into a contractor bag. Source:

5. Sand Down The Stairs

The fifth step is sanding down the stairs. Before varnishing your stairs, ensure they have been sanded down. Sanding your stairs is important because of the traction from footsteps. The wear and tear your stairs are subject to make sanding a pivotal part of the varnishing process.

No matter how careful you are, depletion is sure to occur. Sanding will remove any stains or scuffs that will appear on your stairs. Also, sanding your stairs will remove the previous paint and varnish.

When sanding your stairs, use medium-grit sandpaper. Medium-grit sandpaper is rough enough to ensure a course surface after sanding. Using sandpaper that has less grit will be unable to remove the previous varnish on the stairs. Use sandpaper that has a grit of 100 or less.

6. Clean Up The Stairs

The sixth step is cleaning up your stairs. After sanding your stairs, there will be dust everywhere. Make sure all of the dust is removed before varnishing your stairs.

Below are tips to clean up your stairs before varnishing:

  • Vacuum the stairs
  • Use a cotton rag
  • Use a damp mop
  • Use a tack cloth
  • Sweep the stairs

7. Thin The Varnish

The seventh step is thinning your varnish. Thinning the varnish is not required for the first layer, particularly with polyurethane varnish, as it is oil-based. Although thinning the varnish for the first layer will cause no detriment to the final product, it will result in having to apply more layers.

For the other coats of varnish, add a thinning agent. Diluting the varnish will result in fewer streaks and bubbles in the finished product. Although it depends on the varnish and thinning agent being used for your stairs, it is recommended that your varnish should be a mixture of 95% varnish and 5% thinner. A combination of thinly applied coats and a leveled-out varnish will result in little to no imperfections in the end result of your stairs.

8. Thinly Apply The Varnish

The eighth step is thinly applying the varnish. When you apply your varnish, do so in thin coats. Doing lighter coats will result in a cleaner finish. To improve the quality of your finish, apply the varnish in many thin coats rather than a few thick ones

To successfully apply the varnish to your stairs, follow the steps below:

Only the tip of your brush should bend. If you’re right-handed, start in the upper-left corner of the surface. Varnish a one-foot-square area, brushing in the direction of the wood grain—never back and forth—then move on to an adjacent square of similar dimensions. Proceed in this way until you have a full coat. Source:

9. Allow Varnish To Set

The ninth step is allowing the varnish to set. When applying the varnish to your stairs, allow the coast to set in between each application. The amount of time your varnish needs to set depends on the thickness of your application and the temperature of the room.

At times, your varnish will be able to dry in just four hours. However, it is recommended to wait twenty-four hours in between each application. Waiting for the allotted amount of time will ensure your varnish is finished drying, and will not compromise the results. Not waiting enough time will inhibit the results of your varnishing.

10. Repeat Steps 5-9

Once you have finished your first application of varnish, you are ready to continue with the process.

Below are a list of the steps that need to be repeated for the best results:

  1. Sand down the stairs
  2. Clean up the stairs
  3. Thin the varnish
  4. Thinly apply the varnish
  5. Allow the varnish to set

Repeating these steps is sure to provide your stairs with a quality finish. The amount of times these steps need to be repeated depends on the thickness of your applications. However, it is recommended to repeat this process three to four times.

Ricky Kesler

With all of the projects I've done over the years, you'd think that I work on my house full-time. But I actually enjoy other things like spending time outdoors and time with my family.

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