How to Skim Coat a Textured Wall


February 5, 2023

I'm a Latina DIY mom living in Texas.  I'm a retired RN and autism mom using DIY as my creative outlet.  Join me on this journey as I learn and share the things I am learning along the way. Thank you for being here!
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skim coated wall

Skim coating a textured wall, or any wall for that matter is not for the faint of heart. Just saying! 😊

A “skim coat” is a thin layer of joint compound that’s applied to a wall to create a smooth surface. In this Texas house, all our walls have knockdown texture. I wanted a smooth surface for an accent wall so I decided to skim coat.

textured wall
This is knockdown texture

My little girl has been asking me for a pink room for almost a year. She is outgrowing her toddler bed and wants a “big girl” room like her brother. I’ve been avoiding this project altogether because I actually think her room is really cute and doesn’t need to be redone. But I redid big brother’s room when he turned 5 so it’s only fair I give her the same thing even if it’s almost a year late. 🙂 So this is the beginning of her room makeover and it begins with learning how to skim coat a textured wall!

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I will be adding an accent wall to one side of her room, which means I have to prep the walls. We have knockdown texture on our walls and I would like for the walls to be smooth because I will be adding picture mould. Having a smooth wall isn’t “necessary” – it’s mainly a preference. There’s a couple ways to get your walls smooth – either use eucaboard over the existing walls or skim coat. I decided to try skim coating for the first time! I’ve never done it before and let me tell you, it was a huge learning process.

Supplies (You can find these on Amazon or any big box store):

Drywall skim coating supplies
10" Joint Knife
Basic Supplies for mudding

1. Prep the Room

I moved all of the furniture to the middle of the room to give me space to work. There is carpet in this room so I laid down plastic drop cloths along the edge of the wall I was working on to protect the carpet. I used painter’s tape around the edges of the wall to contain the drywall mud to only the area of the wall I needed to skim coat.

drop cloths, prep for skim coating
I made sure the edges were sealed well so I wouldn’t have mud leak onto baseboards.

2. Prep the Joint Compound

Add Dawn dish soap and water to the joint compound (also referred to as mud). To be honest, I only added the dish soap to the joint compound because I saw someone else doing it. I also added water until I got a pancake batter consistency. Apparently adding dish soap helps reduce the amount of bubbling that tends to happen when you are skim coating over existing texture. I chose to go with Dust Control joint compound because I read that it is not as dusty as the other joint compounds and because I was working in my little girl’s room, I wanted to minimize dust at all costs. Not sure if it was the type of joint compound I used or the Dawn soap, but I had no bubbling whatsoever when I put the first coat of mud on the wall.

Mixing joint compound
Dust control joint compound with Dawn soap and water.

3. Start mudding (1st coat)!

I added smaller amounts of mud to the mud pan and spread the mixture across the wall. For the first coat I used a 6-inch joint knife (do not use a 6-inch joint knife to do this because it will take you foreverrr – you live, you learn. Use a 10 inch knife or wider). Because our walls are so textured, I figured I would need to put at least 2 coats of mud on the wall. So I planned on my first coat not looking perfect. Once you have put the first coat of mud on the wall, depending on the type of joint compound you use, you will want to wait 24 hours for the mud to completely dry before applying the second coat.

Mudding a textured wall, skim coating a textured wall
1st coat of mud on textured wall
This is what the wall looked like after the 1st coat of mud

If you’re like me and don’t work out consistently because #momlife, plan on being sore the next day. I woke up the next morning with my arms so sore I thought they would legit fall off.

4. Sand the first coat.

There are 2 ways you can sand. You can go traditional and use a sander to smooth out the major areas where the skim coat went on unevenly or you can do a wet sand. If you choose to go the traditional route with a regular sander, be prepared for a LOT of dust. It’s also very important that you wear the proper PPE because you don’t want this stuff getting in your lungs. Cover everything, including any vents.

I chose to do a wet sand because it’s not as messy. However, wet sanding does require some elbow grease. What you do is you take a grout sponge and soak it with warm water, and basically “rub” the areas on the wall that are the most uneven. I used a grout sponge that had a rough side and a smoother side and I found it to be easier to use the rough side on the areas that had a lot of uneven spots while the rest of the wall was ok with me using the smooth side. Remember, the first coat will not be perfect, so just sand the “high spots.” The final coat is where you want to be more “picky.”

wet sanding after skim coating

5. Add second coat of joint compound.

For the second layer of joint compound I ended up using all purpose joint compound but I’m not
sure I loved it more than the dust control. I say this because as I started applying the mud to the wall, I noticed I started getting a lot of bubbles and I didn’t know how to make them go away! While it’s basically the same process as when applying the first layer, this time I didn’t add Dawn soap. So for the second batch I mixed, I added Dawn soap to the mixture. But I didn’t notice a substantial difference so I kept going and tried not to apply as thick of a layer. I also used the 10-inch joint knife which made the process go by quicker. When applying the second layer, this is where you need to be a little more picky so you don’t have to do as much sanding when it dries.

My final coat went a lot faster and it also looked really good until it dried the next day and I could see the major imperfections. Hehe. . . I did a final wet sand and decided to live with what I had. From start to finish this small wall took me 3 days to do. It’s not perfect, but it definitely gives me something to work with for the accent wall that I will be adding there!

DIY skim coating or mudding of a textured wall

6. Prime time, baby!

The last and final thing you are going to do before you apply paint, is apply a good primer. There are a ton of different options when it comes to Primer. I went with Zinsser 1-2-3 because I had a gallon leftover from a previous project. I painted one coat but depending on the type of primer you go with, you may have to do 2 coats. Follow whatever the instructions say on the can. 🙂

priming after mudding

Mudding is an art. I have a new appreciation for the people who do this for a living – it’s a lot of work and takes time to perfect your craft. Much respect to you all!

Here is the link to the reel where I share my experience with how to skim coat a textured wall. It’s a doable DIY that in my opinion, is harder than it looks. 🙂 But it was definitely worth the money I saved by doing it myself. As always, let me know if you have any questions! Happy skim coating!

skim coated wall
Hooray for smooth walls!

If you’d like to see how the room turned out you can check out the post about my daughter’s bedroom glow up!

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