Now that the exterior siding, windows and doors, and roof are done on the Fixer Upper Main House, it’s time to get moving on the interior. While the walls are in decent shape, the knock-down texture from the 80’s is really dated. I want the calming, modern look of smooth walls! But I don’t want to pay big money for that. This post will show you how to DIY skim coat smooth old textured drywall for a modern finish.

Here is a photo where you can really see the 80’s knockdown drywall texture. This texture covered the whole house and was painted with white semi-gloss paint everywhere. Time for an upgrade!

Steps for DIY Skim Coat Smooth Old Textured Drywall:

These the basic steps to DIY skim coat old textured drywall for a modern smooth finish.

1. Clean walls and ceilings with TSP substitute cleaner to get rid of grease, dirt, and grime.
2. Prime walls and ceilings with an all-purpose primer such as Kilz. This creates a surface for better adhesion of the joint compound.
3. Spread drywall joint compound on the walls and ceilings. Use a drywall taping knife or trowel to smooth and spread the joint compound. Depending on the amount of texture, you may need up to 3 coats to create a smooth finish.
4. Sand walls and ceilings smooth.
5. Prime and paint walls and ceilings.

Those are the basic steps. Now I’ll go into more detail on each step to show you what tools I used, why I did certain things, and give you some tips and trick I learned along the way.

1. Clean Walls and Ceilings:

If you want to smooth old textured and painted walls, it is very important to clean off built-up grease and grime to create a surface that the new joint compound will stick to.

I used concentrated liquid TSP substitute from Home Depot and diluted it in wide bucket per directions on the label. Then I wiped down the walls and ceilings using a flat microfiber wet-dry flip mop.

The label for the TSP substitute cleaner says that it, “leaves surface clean without rinsing.” But I wanted to make sure that I gotten as much grime off as possible and that nothing would interfere with the primer, so after the TSP cleaning, I did another round of mopping using water only as a rinse. Then I also toweled off the walls and ceilings to dry them and clean them off one more time.

I’m not a tall person, so a work platform was handy to stand on when mopping the ceilings. To towel off the ceilings, I wrapped a towel on the flat mop and rubbed it around. If you had a lot of extra flat mop covers, that could work too.

Be sure to let the walls and ceilings dry before moving on to the next step!

2. Prime Walls and Ceilings:

This next step is pretty straight forward. You simply want to prime your cleaned and dried walls and ceilings. I used Kilz all purpose primer applied with a roller and a brush. It took a few days to paint the whole interior of the house by hand. If I were to do it again, I’d use a paint sprayer and be done in a day. But you live and learn! One coat was all I used and that’s worked fine.

3. Spread Joint Compound:

Joint compound, also known as drywall mud, is what’s used to finish drywall joints and corners. This is what we’ll spread all over the walls and ceilings to create a smooth finish over the old textured drywall.

I’d recommend premixed joint compound. That way you’ll avoid any chunks of unmixed powder that you’ll inevitably find if you mix your own.

I used Westpac all purpose joint compound. It is a pre-mixed, vinyl-based compound with about a 24 hour drying time. I chose to use this compound because it is inexpensive for the 4 gallon bucket, and I liked that is has a vinyl additive. The vinyl supposedly allows the compound to flex slightly and helps it resist cracking under temperature changes during it’s lifetime.

There are a number of ways to spread joint compound when covering a drywall texture. A lot of other blogs recommend mixing some water to the joint compound to get it thin enough to apply with a paint roller. While this does allow you to cover a lot of wall space in a short amount of time, I was concerned that the added water would increase the likelihood of cracking as the mud dried. I was particularly concerned about this because the old knockdown texture was relatively deep when compared to say an orange peel texture. So there would be thicker areas of joint compound between the knockdown texture. Thicker layers = more likelihood of cracking anyway, so I decided to NOT add water.

Instead, I troweled the joint compound onto the walls and ceilings. I know what you’re thinking! OMG, didn’t that take FOREVER? Yes, yes it did. It was a real slog. A never-ending journey. A dark night of the soul. Haha, no it wasn’t that bad, but it did take a long time. I put on some good podcasts and got to work. Thankfully, I had a few months to slowly apply the joint compound while I worked out my plans for the kitchen and bathroom.

Here are the basic tools I used to apply the joint compound. Just keeping it simple with a 14 inch mud pan and a variety of taping knives.

Here I am troweling away on the ceiling in the living room. Spot lights help a lot to see divots and missed spots when applying the drywall mud. You can see the texture still visible under the first layer here.

You really need about three coats with drying time in between to get the walls nice and smooth. Here I am applying the compound to the ceiling while standing on a work platform. This is tedious work(!) any my arm often started to fall asleep. Just keep going. You’ll get there eventually.

The good news is that you don’t need to keep a wet edge with the mud. You can apply a section of wall, let it day, and keep going the next day.

However, make sure each layer is dry before you apply a new one.

4. Sand Walls and Ceilings:

Once all the joint compound it dry, it’s time to sand off any bumps or lines. Note: this means bumps or lines in the applied drywall mud. If you still have bumps from the actual drywall or old texture, you need to apply more mud.

The easiest way to do this would be to rent or buy a drywall sander with a vacuum. I wish I’d done this! But I was going through a true DIY by hand phase and was trying to keep costs very low, so I went the insane route and sanded this all by hand. It saved money and was a good workout, but I won’t be doing that again.

I did try a handheld drywall sander with a vacuum attachment. It worked fairly well, but I felt like I got a better finish with a pole sander. I kept the shop vac running to pick up extra dust.

Here I am in my sanding safety gear. A head lamp to see the bumps in the finish and a really good dust mask are critical. I kept having trouble with my goggles fogging up, so eventually I just wore more open air safety glasses and accepted that some dust would get in my eyes.

Here I am dusting off outside after a heavy round of drywall sanding. It gets everywhere!

You’ll probably want to quit sanding when they drywall looks good enough. Word to the wise, smooth drywall shows all it’s imperfections! So if you don’t sand it, you will see it…forever. Sorry. But it’s true. If you get tired, take a break and come back to it refreshed.

5. Prime and Paint Walls and Ceilings:

With the sanding finally done, YAY!, it’s time to prime and paint. Before you do that, you want to make sure all the dust of off the walls and ceilings. Otherwise, the paint won’t adhere as well.

I used the shop vac to quickly go over everything and then dry mopped with the flat microfiber mop to pick up any last dust.

By this time, I’d given up on doing everything by hand and splurged on an airless paint sprayer. This thing is an amazing time saver! I was able to do a coat of primer over the all walls and ceilings in one day. Hallelujah!

Here is my favorite, well-used paint sprayer. I’d recommend it if you have any sort of paint projects coming up.

With everything painted, the smooth drywall looks AMAZING! I could hardly believe the job was actually finished, lol. Who knew we could smooth old textured drywall and have it look so good? It is so much more modern and calming.

But, it’s tough to show the finish on camera. So here is a comparison of the before photo with the smooth drywall after. It’s that amazing? Yes, that’s the old textured painted drywall just smoothed over.

DRYWALL UPDATE: I am happy to report that three years after applying the joint compound and smoothing the drywall, it still looks fantastic. There have been no chips or cracks or anything, and the house has been through some large temperature swings – from high 90’s F. in the summer before we had air conditioning to nearly freezing when we left for Christmas to visit family and no one was left to feed the wood stove. It’s holding up great.