How to repair cracked plaster walls for charm and patina

red wall

Clemence Taillez via Unsplash

In this video I show you how to repair cracked plaster walls for charm and patina. With a few tools like a putty knife, drywall (joint) compound, a five in one tool, water, and a sponge, you can make your old, cracked plaster walls a work of art.

You can have fun repairing cracks in your old plaster. Especially if you see the imperfections as charm and patina.

Interestingly textured plaster walls are timelessly classic and old worldy feeling. I’m not talking about icky popcorn or orange peel textures! Think Provence and Morocco, instead…

If you prefer to read, I’ve written it all out for you just below the video. Thanks for watching or reading.

Prep Work Before Repairing Cracked Plaster

I have finished removing all the wallpaper in this room and I have cleaned the walls with a Dirtex and hot water solution.

Repair Cracks in Plaster Walls

And now I am left with all of the cracks in the plaster walls. In spots, I’ve got crumbling plaster, too.

This room has quite a a few up high, and down low, and they all have to be filled in before we can get to painting. It’s a lot of cracks, but it’s really going to go pretty fast. Patching plaster is actually kind of fun, especially after washing walls. Which is … not fun.

Tools You Will Need

First up, you need a putty knife. Anything like this. This is a great size if you have bigger cracks. You can use something bigger, but this size is pretty much a universal. It’ll do pretty much everything you want. Even something like that back there.

You’re gonna want a tub of some water and a couple of these nice soft sponges. You’ll also need a dry, clean paintbrush. And then the last thing is the good old five and one tool.

Widen the Cracks in the Plaster

Let’s say, for example, you have a couple of cracks like this, and they’re pretty wide. So before you try to fill this in, you actually want to sort of make it wider ,so you kind of like, perfect the crack so that you can fill in more. I’m going to take my tool and I’m going to just widen the plaster crack a little bit with the pointy edge.

And I’m going to do that so that when I put in my joint compound, it sinks deep into the crack, and then I can smooth it over like that. Instead of the crack being really tight and trying to smooth over, it like let’s say I did this one, and I just tried to smooth over.

I’ll give you an example. I tried to smooth that over. The joint compound is not going to be able to get in there, and it’s just going to kind of be on the surface, and very chunky, and the crack might even sort of push it out as the wall moves more.

We have cracks because the walls are moving, so it’s going to happen again. So the way to to to mitigate that is to actually make your crack bigger before you start, so I’ve done that. It’s quite the crack.

Once you have widened your crack, just take your brush and brush away any loose plaster mess so that you can put your new plaster on nice and neat.

Smooth Joint Compound Into Cracks

And then I am simply using joint compound. Just load up your putty knife. This putty knife has a little bit of give to it. It flexes a little bit and that is much easier to work with than, for example, the five in one tool, which is quite rigid. As much as I love this tool, it’s not the best for applying plaster. These little putty knives are better, just because of that slight give. It gives you flexibility. It’s just like frosting a cake. You just you want a flexible spatula. It’s the same concept.

I’m just going to take my joint compound and I’m going to smooth it into my crack just as if I were frosting a birthday cake. Then once it’s filled, scrape off the excess back into my bucket. Then I’m going to take my clean knife, and I’m going to come over here and I’m going to smooth out the excess, just like I was smoothing out the top of a cup of flour before I dumped it in a bowl.

Just take that off of the trim, if a little bit gets it down on your baseboard, that is no biggie. You can wipe it away before it dries, and even if you find some after it dries it’ll come right off with water.

Wash Over Joint Compound with Water

Now it’s time for my sponge.

I’m just going to take that and I’m going to smooth out the rough spots, there. You can see it got all the way into the crack, but then there’s roughness because the skim coat broke off, and we’re left with the – I don’t know what that’s called, that, that layer of rough plaster with sand in it. That’s showing through, and we don’t want that. I don’t want that to show, so I’m going to cover that up too.

Now that I’ve got that deep crack filled in, I’m going to smooth it out. A very light touch with the sponge. You can see it’s covered somewhat so, scraping off the excess and then smoothing it with my slightly damp sponge, ever so slightly damp, the lightest of motions over.

The Charm & Patina of Old Plaster Walls

The great thing about smoothing out all of your patchwork with a sponge is that it really minimizes the need to sand it later. You could sand it if you wanted to. You could also not. It depends what you want your wall to look like. Some people want their walls to look perfect and some people see the slubs and variations as a feature.

I fall into that category, so I’m covering up these cracks to enhance the strength of the wall, for structural reasons, but I am not concerned that it looks bumpy because I think that’s part of the charm of an old plaster wall.

I like it when it looks like you were trying to make it nice and neat and you were patching some cracks, but I don’t like this sort of, like, oh I’m going to do this sculptural wall. I don’t care for that. If you want to do that kind of thing, go for it.

But someday I’ll show you my hallway where they did that. I think it gets old really fast. I think the old – I like the look of, this has been repaired, and we’re not hiding that fact, but we’re not trying to fancy it up, either.

That’s my goal with these walls. They’ve been patched; they’re old; they’re venerable; they’ve got cracks that have been repaired; we’re not hiding that by re-skimming, or anything like that, but, um, we’re also not trying to make it fancy, or into something that it’s not, or changing the texture over much. I’ve scraped off enough with the knife.

Now I’m going to take my slightly damp sponge and I’m just going to barely touch it to the wall down there. I’m going to press a little because I got some on the woodwork, which I don’t want.

I’m going to go back and just kind of go vertically down without any pressure at all, just letting it drag along by gravity’s force alone and that you can see these weren’t – they are in the plaster that’s not a mark that was left by my putty knife. This crack is covered.

The plaster is nice and deep in there. It is not going to come out, or get squeezed out as it moves. That is the character of the wall right there.

Why I Think Uneven, Patched Plaster Walls Have Charm and Patina

I wanted to go in a little more detail about what I mean about the character of the wall without overly texturizing but also not hiding the fact that you had to do repairs, either.

I thought I’d show you this other wall with these larger cracks, and show you what our philosophy is. You can see over here these cracks start way up at the ceiling and they continue down. Diagonal cracks. We’ve started to work on them right here at our eye level and there’s just, there’s some deep cracks. They look like that. We have covered them and filled them with plaster and we are not going to put tape on them or re-skim coat or anything.

I also dislike using mesh tape, fiberglass mesh. I don’t think it works well with these old plaster walls. It doesn’t look right, and the repair doesn’t last, either. And you can always see the mesh pattern. I don’t use old lime plaster, either. It’s just joint compound. We have just done the repair. We’ve simply done the repair, and we are going to let that texture stay.

We might sand lightly some of those lumps and bumps there, but the overall texture, we are going to let that stay, and we are going to paint that.

We think of that kind of texture as the patina and the beauty of the old plaster walls. Here’s some dings and things, as well, that we might not even fill in.

If you can let yourself look at these kind of imperfections as a feature, and not a problem, or where you need to re-skim coat and just have this perfect wall, you will enjoy working on your old plaster walls a whole lot more. Plaster repair can be a fun, creative process.

More Ways to Repair Cracked Plaster Walls

To be perfectly frank, my method described here will probably raise a few eyebrows with purists. I did not use lime plaster. Only modern materials.

If you’d like more information about repairing old plaster walls, Victorian Project has an extensively detailed post all about it. They go into the differences between lime plaster and gypsum, and using lime plaster for repairs.

Stacy from Blake Hill House has a great post about how to replace, as well as repair, plaster using plaster patch and joint compound. She also takes you through the decision making process of why you’d use modern materials, when you’d use historically accurate materials, and why it’s probably ok to do both, and learn as you go.

If you’d like to know about some all natural, breathable paints that look great on rough plaster walls, check out my post, Milk Paint On Walls.

Thank you so much.

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