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Can You Use Joint Compound on Plaster? (Explained)

Joint compound is a type of drywall mud that is used widely for construction purposes. The use of joint compound is vast as it can be applied on different surfaces and trims. Joint compound can even be used to repair holes on the wall. 

Today, we are going to discuss and find out whether one can use joint compound on plaster. 

Can you use joint compound on plaster?

Joint compound can be effectively used on plaster surfaces including plaster walls and plasterboards. The adhesiveness of joint compound gives it the ability to be used for repaired jobs on plaster. Multiple layers of joint compound have to be applied on plaster for the best possible result.

Let’s see if joint compound can be used on different types of plaster surface. 

Joint compound on plaster walls:

Plaster walls sometimes need repair work done on them. When it comes to repairing holes and cracks on plaster walls, joint compound is highly suggested by experts because of its adhesive quality. 

Joint compound is one of the strongest drywall muds available in the market and they are very effective on many different kinds of surface. Plaster walls belong to the list of surface joint compounds that can be used on. 

But one of the challenging things when it comes to applying joint compound on plaster walls is to match the joint compound with the texture of plaster walls. 

It can often create uneven texture on the repaired areas due to the difference between components of joint compound and plaster. 

Joint compound on plasterboard:

Plasterboard is an alternative to plaster walls. Instead of applying plaster on walls, you can directly add plasterboards. The component of plasterboards is more or less the same as plaster. This is why joint compound can be used to fill holes and cracks on plasterboard too. 

How will joint compound or drywall mud stick to plaster?

Joint compound is famous for its hardening quality and adhesiveness. Most often than not joint compound or drywall mud sticks to plaster without any added pressure

But mesh tape is added onto the joint compound coat to make sure that the adhesiveness of the joint compound reaches its full potentiality. 

You can even use a second layer of joint compound after the first layer has dried if you have any doubt about the adhesiveness of the joint compound on plaster. 

Can you skim coat plaster with joint compound?

Sometimes plaster walls and surfaces need to be skim coated in order to hide the unevenness of some areas. Joint compound is a good choice when it comes to skim coating plaster

But the layer of joint compound applied as skim coating has to be excessively thin. It does not need thick layers of joint compound like repairing jobs as hiding unevenness and hairline cracks is a small gig. 

However, multiple layers of thin joint compound have to be applied for the overall success of the process.

Can you patch holes in plaster with joint compound?

The holes in plaster can be effectively and easily patched using joint compound. You can use premixed joint compound to repair any holes on plaster walls. You will have to give the joint compound enough drying time on the plaster surface. 

Otherwise, the process will not be a success. 

You will have to use another layer of joint compound if the first layer does not do its job properly. Grit sandpapers can be used to smooth the repaired holes. You can also apply a skim coating technique to blend the texture of joint compound on plaster walls. 

How to apply joint compound on plaster walls?

Applying joint compound on plaster walls might seem like a daunting task if you do not have any prior experience. However, there are some steps and methods you can follow to implement this task. Let’s discuss them in detail. 

Identify the holes and cracks:

First of all, you will need to identify the holes and cracks on your plaster walls. After you have successfully identified those holes and cracks, you can begin the repairing process by scraping out excessive dirt, debris and paint from those holes and cracks. 

Apply the joint compound:

In this step, you will need to use joint compound on those holes and cracks. You can take the help of a putty knife to apply the first coat of joint compound on the holes and cracks. You will need to put out an extra bit of joint compound using the putty knife. 

You will have to attach mesh tape on the applied joint compound. The application of mesh tape can be done using the putty knife.

Let it dry:

Joint compound needs a huge amount of time to dry. You will need to give it at least twenty four hours before you can start working on it again. You can use the dehumidifiers to fasten the drying time. The joint compound will change its color slightly when it fully dries. 

You will need to apply a second coat of joint compound if the first coat does not do its job smoothly. 

Use sandpaper:

After the joint compound has completely dried off on the plaster walls, you will need to use a fine grit sandpaper to smoothen out the layer of joint compound on the plaster walls.

Skim coat it:

If the repaired holes and cracks look uneven after applying joint compound, you can skim coat those areas. It will give a more satisfying texture on those areas.

Is plaster the same as joint compound?

Plaster is not the same as joint compound as there are many differences between these two products. First of all, plaster is used to cover the entire wall for construction and decoration purposes. 

But joint compound is not used on such a large scale as their primary job is to repair holes and cracks on the walls. 

Plaster and joint compound function differently too. Joint compound takes longer than plaster to dry off completely. Plaster is also more flexible than joint compound and can be smoothen out more easily. 

The only common trait between these two products is that both of them have gypsum as one of their core elements. Other than that, plaster and joint compound are very different from each other.

What is the difference between plaster and joint compound?

Sometimes people get confused between plaster and joint compound. But there are some distinctive differences between both of them. Let’s discuss them in detail. 

The core difference:

Joint compound is one of the most famous drywall muds in the construction industry. It is used to repair holes and cracks on the wall. On the other hand, plaster is not used for repairing purposes. The primary use of plaster is to work as a filling material on walls. 


The main component of joint compound is gypsum. Gypsum gives the joint compound a texture similar to cake frosting. On the other hand, Gypsum, cement and lime – any component out of these three can be the main component of plaster. 

Drying process:

Joint compound takes a huge amount of time to dry off. The more joint compound you apply, the more time it takes to dry off completely. But time is not a concern when it comes to applying plaster. 

Plastic takes significantly less time to dry off when you compare it with joint compound. 


Joint compound hardens when it dries off. That makes it impossible to shape it to your liking or preference. Most of the time you will have to apply multiple layers of joint compound in order to get the perfect texture. 

This is not the case for plaster as you can shape it to your liking and preference. Because plaster does not harden as much as joint compound.


Joint compound often comes in pre pre-mixed container and you can apply it directly out of the container. But plaster has to be mixed manually beforehand and it requires you to be cautious. Because mixing it in wrong proportions can hamper the job. 

Can you paint over the joint compound?

You can definitely paint over joint compound if you follow the correct steps. First of all, you will need to sand the joint compound after it has dried off with grit sandpaper. You will have to get rid of extra dirt and debris after you have sanded the entire area. 

The next step is pretty crucial as it will dictate the success of the painting process. You will need to prime coat the joint compound before you can apply the paint over it. You will have to refrain from painting before the prime coat dries off completely.

Final Thoughts

Joint compound is usable on plaster walls due to its adhesiveness. It is applied to hide cracks and holes on plaster walls and plasterboards. Mesh tape, sandpaper and skim coating can be applied to blend joint compounds on plaster surfaces. But joint compound needs enough time to dry on plaster.