Whether your home is old and used plaster for the wall or you went for a higher quality wall material for a more stable home, painting over plaster can be tricky. Plaster is definitely more resilient than drywall is and it’s difficult to know just how well the paint will take to the wall.
Painting a plaster wall is very similar to painting drywall. The plaster will soak in paint in higher concentration and more sporadically. Plaster walls need a good primer to create an even paint job and the best paint to use is acrylic latex-based paint for hard surfaces to paint.
Plaster is a tricky material to work with and needs care when being used, especially with paint. To understand more about plaster itself and how to paint it effectively, keep reading.
What Is Plaster?
Plaster is a dried powder that when mixed with water creates a paste that can be used to create a smooth wall. This paste has been used efficiently since the mid-1900s but plaster itself dates back to thousands of years ago.
Plaster, when hardened, creates a wall that is both insulating and flame retardant. This is what made it such a popular choice in the 1900s and is a reason to still be used today. Many plasters will chip or crack over time, but is durable and is efficient in their uses.
Most plasters are made of gypsum but may also be made of lime, and can create a hardened effect when dried completely.
Do I Need To Prime My Plaster?
When you decide to paint your wall and you find out that it is plaster, this is a good question to answer. The natural makeup of plaster makes it a very porous material that will drink up the paint that you put on it.
This will make the paint sporadic and unreliable in its finished look. It will not look very clean and may cause the paint to have to be replaced in a short span of time.
To create a good base for the paint to last and will keep its integrity, you must prime the wall correctly. This base is essential if you want a clean-finished wall in your home.
Best Paint For Plaster Walls
Plaster, once it is primed properly, will take any high-quality paint that is used for walls. It really comes to choosing the color that you wish to add to your home.
So the question really becomes what is the best primer that can be used on a plaster wall. Below is a table for your needs to search for good high-quality primers to use.
|Rust-Oleum 2004 Zinsser Bulls Eye 1-2-3 Primer, 1 Quart, 946 ml, White
|KILZ 2 Interior/Exterior Multi-Surface Primer, Sealer & Stainblocker, White, Water-Based – New Look, Same Trusted Formula
|Adhesion 1 Gal. White Bonding Interior/Exterior Primer
Preparing The Wall For Painting
Whenever you take on a project to handle by yourself it is important to prepare your workstation to fit the right conditions to start right and finish with a good end product.
In regards to plaster, whether you applied the wall by yourself or someone else did it, it is likely to have some lumps and bumps because of the texture by which plaster is made. There is a simple and easy fix to this, but it takes time.
Simply take some sandpaper and sand the uneven sections of the wall down to an even layer of plaster. This will create a nice even look on your wall and will make the finished product look much better.
When sanding, you can do so by hand, or you can use a machine sander on a low power level. You don’t want to push too much, because this could ruin the plaster and create a bigger problem than you had to start with. Apply slight pressure to take off bumps, but leave the wall itself.
When it comes to corners, you can sand these down as well. You might see some metal edges on your wall and this normal. It is ok to see this, just make it smooth with the rest of the wall and the paint will go on fine to the corner with metal edges showing.
In regards to the type of sandpaper grit to use, begin with a lower grit, perhaps 80 grit or maybe even a 60 grit, and work your way to a higher grit ending at 120 grit. This will give you an edge at the beginning that will take off the uneven sections and then the higher grit will give a nice finished look to it.
If there are sections where the plaster seems to be missing or absent, simply take some plaster and fill in those spaces. These areas will most likely be near corners or windows and doorways. It’s not a hard fix and is easy to workaround.
Painting The Plaster
Now that you have prepared your plaster wall for painting it is time to prime the wall. You can’t just go into painting the wall because plaster needs a delicate process to get the paint to stay.
Priming The Wall
Priming the wall requires multiple layers consisting of a mist layer and then a base layer to create the perfect surface for the paint to have a long-lasting effect.
But before you start applying the mist layer you should probably decide how you are going to apply it. By paint roller, or by paint sprayer. Each has its pros and cons and hopefully, the next sections will give you enough information to make your decision.
The sprayer gives a nice clean look to the plaster, it will look as though a mist covered the wall, not entirely covering it but creating a clean place to start the base layer. The sprayer will only be used for the mist layer and then maybe for the base layer but might be advised against it later on in this article.
When using the sprayer you will want to hold it 18 inches from the wall and use long slow swipes. This will ensure that you cover the entire wall and really get the paint to soak into the plaster itself.
Using the sprayer will be much faster than the roller, and will give you a more even finish. But it has its own setbacks, the main one being that it will get paint everywhere in the room that you are painting. Make sure to lay down drop cloths and to cover any outlets, windows, doors, or even outlet screw holes.
The paint roller has a higher functionality of precision when it comes to applying paint, but it may not be the best for putting on the mist layer. It may create an uneven layer that will cause problems later on in the painting process, not giving your paint the even finished look that you will want.
The roller will also be slower as it will require you to go back and forth to replenish paint more often. This may not be a huge deal, but it might be worse in the long run.
The Mist Layer
The mist layer, as was explained above, is what soaks into the plaster itself. Plaster is very thirsty for the paint that it will receive, which can make it uneven if not primed correctly.
The mist coat will act as part of the primer that must be applied to create an even finished look. It is actually best to use a 1-1 ratio of primer and water to have it soak in nicely to the plaster itself. So for every gallon of primer, mix it with 1 gallon of water.
This mixture will still dry well enough and create a good surface for the base layer to be added on top and will prevent the final paint job from peeling off.
You should plan to do at least 2 layers of this mist layer and to make it methodical. You need to get a good enough surface for later. Doing more layers might be beneficial, but it is up to you to decide how many layers you would like to apply. Each layer needs to be dry before moving on.
The Base Layer
The base layer is meant to prepare the wall for the final coat of paint and will look almost like a final paint job itself, just white. Having that nice neutral background will help the final color be more vibrant and look more like the actual color that it is.
This baselayer will use the same primer, just with less water mixed in. By doing this it will still soak into the plaster where it needs to but create the perfect conditions for your paint to finally go on.
But it can be tough to use the sprayer for this layer. Because you are using thicker paint it may create clogs or other such problems with your sprayer that may be bothersome. It might be simpler to begin using a roller at this point.
Make sure to apply multiple layers of this base to prepare for the finishing paint layer to be added without flaw. Make sure that each layer is dry before applying the next layer on and moving to the final step.
The Paint Layer
Now that you have finished priming the wall you can begin to paint the wall with its final layers. This will need some additional tools that will make it easier, and give it a better look.
You will need to have a paint roller, and a hand brush that can be used in spots that the roller won’t be able to get to. Use the hand brush to get these tight areas nicely applied with paint.
I would suggest starting with the corners, putting on a thin layer of the color that you are going to put on, and let it start to dry. Then begin to put the first layer of the paint onto the wall with the rollers.
When using a roller, use long methodical strokes without putting too much pressure onto the wall. If there are beads of paint being pushed out each side of the roller then you are most likely pushing too hard. These beads are easy to fix. Just blend them into the other layers that you have already added.
When it comes to a corner with the roller keep it roughly 1/2 of an inch from the corner and then go back and fill in the corner with the hand brush. This will give the corner a nice blend with the rolled paint.
The paint layer will need multiple layers, each adding to the final product. It will be pivotal to let these dry to give it this look. Make sure to blend any extra paint by going back over it. Also, it is important to avoid thick lines from showing through the paint. That is why long slow strokes are important when using a paint roller.
Old Plaster Vs. New Plaster
Old plaster can be easily recognizable as it will most likely look rugged and cracked in multiple spots. Others may have tried to hide it up with paint, but the old primer breaks down and often will need to be replaced.
But old plaster gives a house the feel of a masterpiece. High-quality plaster finishes are something that many people respect and will try to preserve the best they can. Old plaster, though it may be less durable due to its years can give a home a nice old-time feel with plenty of stability.
Though efforts to preserve old plaster occur, it may be that new plaster needs to replace the old plaster. The process is not too difficult and will leave your home looking nice afterward.
If you are removing old plaster, make sure to cover up your mouth and nose with a face mask to avoid breathing any of the plaster in. Also, it’s advised to wear protective goggles.
New plaster provides a great new look to your home that is not too difficult to apply to your walls. Whether you do it yourself or have a professional do it, the finished look will satisfy you, especially if it is painted correctly.