How To Properly Skim Coat Over Wallpaper: My Experience

Reviving your walls by skim coating over wallpaper doesn’t have to be a complex task. As someone experienced in drywall work, I’m here to simplify the process for you. In this detailed guide, we’ll take a deep dive into every step, providing straightforward tips to help you achieve that smooth, fresh look. By the end of this article, you’ll not only have beautifully prepared walls but also the confidence to tackle similar projects.

1. Assess and Prepare Your Wallpapered Walls

Start by examining your wallpapered walls. Look for loose areas and bubbles. Use a sharp utility knife (I highly recommend this Sheetrock Cutting Utility Knife) to cut out any problem areas. Remember, preparation is key.

If you notice any wallpaper that is loose, sticking out, or bubbling, this should be addressed before proceeding. If the wallpaper is not securely adhered to the wall, it will cause problems when applying the skim coat. The moisture of joint compound will cause bubbles to become larger.

2. Choosing the Right Primer and Sealer

Selecting the appropriate primer and sealer is essential to the success covering wallpaper. An oil-based or shellac primer and sealer work best for this task, but due to recent regulations, these primers may not be available in gallons; but quarts only. These heavy-duty primers are heavily regulated due to their VOC content. Until companies figure out a way to minimize the VOC on some of these compounds, you will have to use a high-quality water-based formula or grab the available quarts.

My Go-To Primer for Wallpaper

To lock down that old wallpaper adhesive so it doesn’t bubble your skim coat, you need a heavy-duty sealer. BIN Shellac Primer is my absolute favorite for guaranteeing the moisture from the mud won’t reactivate the old wallpaper glue.

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3. Applying Primer and Sealer: A Must-Do Step

Once you have your primer and sealer ready, it’s time to apply them to your walls. The primer and sealer application is a crucial step because it creates a sealed surface that protects your skim coat from potential issues related to the wallpaper.

Use a paintbrush or a roller and brush set to apply the primer and sealer evenly across the wallpapered surface. Make sure to cover every inch thoroughly. Allow the primer and sealer to dry completely before moving on to the next step.

4. Let’s Get Started with Skim Coating

With your wallpapered walls now properly primed and sealed, it’s time to dive into the world of skim coating. Skim coating involves applying a thin layer of joint compound to create a smooth and uniform surface. This technique is particularly effective for concealing wallpaper textures and imperfections.

For the first skim coat, you’ll use thinned all-purpose joint compound. Taking it one step at a time is essential to ensure a smooth finish. Here’s how to proceed:

• Begin by mixing the joint compound with a little bit of water (2 cups water per 5 gallons joint compound) until it reaches a creamy consistency using a mixing paddle. The goal is to achieve a texture similar to pancake batter.
• For faster application, use a 3/4 inch nap paint roller to apply the thinned joint compound to the walls. It’s important to work on one area at a time to ensure that you can smooth out the compound before it starts to dry.
• Pay close attention to achieving an even and consistent layer of joint compound. This is crucial for a successful skim coat.

5. The First Skim Coat: Easy Techniques

Achieving a smooth and even skim coat requires attention to detail. Here are some tips for a successful first coat:

• Maintain a consistent thickness: Keep an eye on the thickness of the joint compound as you apply it. You want to avoid creating uneven patches.
• Work systematically: Start in one corner of the room and work your way across the wall in manageable sections.
• Check for bubbles and imperfections: While the compound is still wet, inspect the surface. Use a taping knife to gently remove flaws.
• Feather the edges: To blend the edges of the skim coat with the surrounding wall, feather the edges by applying less pressure on the outer edges of your trowel.

6. The Best Tools for Skim Coating

While a 12-inch taping knife can be used, there are more efficient tools available. Using a large skimming blade is a massive game-changer for speed and smoothness.

7. Sanding: Getting Ready for Round Two

After the first coat has dried, it’s time to prepare the surface for the second coat. Use a sanding sponge or sandpaper with a grit of around 150+ to lightly sand the surface. Sanding helps smooth out any uneven spots. Wipe down the wall with a damp cloth afterward to remove the dust.

8. Achieving Perfection with Lightweight Compound

For the second skim coat, it’s a good idea to switch to a lightweight joint compound, such as Plus 3 Lightweight Joint Compound. Lightweight compounds are easier to work with, shrink less, and provide a much smoother final sanding experience.

9. Final Sanding: The Polishing Touch

Once the second skim coat has dried, it’s time for the final sand.

• Begin by inspecting the surface for any remaining imperfections. TIP: Use an LED worklight angled against the wall to reveal hidden ridges.
• Use an electric sander (like the WEN Drywall Sander) to gently sand the entire surface. Work in even strokes.
• After sanding, wipe down the walls with a damp cloth. If you notice any remaining divots, apply a tight, thin layer of compound to those spots and re-sand.

10. Applying the Final Primer & Paint

To ensure superior paint adhesion, apply another coat of the same primer you used at the beginning. This seals the joint compound so your expensive top-coat paint doesn’t soak straight into the wall.

Once dry, it’s time to paint! Use a smooth nap roller, maintain a wet edge, and apply two coats for maximum depth. Step back and admire your beautifully transformed walls!

Conclusion

Congratulations! You’ve completed the journey of skim coating over wallpaper, transforming your walls into a smooth and fresh canvas. From assessing and preparing your wallpapered walls to selecting the right tools, you’ve mastered the art of wall transformation.

Remember, skim coating over wallpaper may seem like a challenging task, but with patience and the right tools, you can achieve professional-quality results. Happy renovating!