Can I Paint Plaster?

Can I Paint Plaster?

Are you staring blank-faced at your newly plastered walls, eager to add a personal touch to your room without a clue where to start?

You’re not alone!

Many DIY enthusiasts are in the same exact situation as you, asking themselves: ‘Can I even paint plaster’?!

Not only is painting plaster possible, but painting can also be straightforward with the right approach.

In this blog post, I will tell you everything you need to know about painting newly plastered walls, including everything from the tools and materials you need to paint fresh plaster to why you need to let it dry before painting!

Let’s get to it!

Painter and decorator rolling a freshly plastered wall

Can I Paint Plaster Walls?

Yes! You absolutely can paint over new plaster walls.

The only real difference between painting new plaster and decorating a regular wall is the added step of sealing the surface before applying a fresh coat of paint!

How To Paint Plastered Walls For The First Time?

So far, we’ve discovered that painting plaster is totally possible!

But how do you actually paint new plaster? I’ve got you covered. In the next section, I will share all the steps you must follow to paint newly plastered walls.

But before you start to paint, it’s crucial to let the plaster completely dry first.

If you don’t let the fresh plaster dry completely, you will encounter various problems when you decorate your walls. When the plaster is dry, the colour typically changes to pale pink – so look out for this.

Tools & Materials Needed

These are all the tools and materials you will need for a superb DIY finish when painting a plastered wall:

  • Angled Paintbrush
  • 12” Paint Roller
  • Paint – you can choose any interior wall paints you like!
  • Primer or White Matt Emulsion
  • Paint bucket 
  • Stirring stick
  • Sandpaper
  • Filler 
  • Filling knife
  • Masking tape

How Do You Prepare Plaster Before Painting?

When painting fresh plaster, the preparation work you’ll do before a drop of paint ever touches the walls is crucial for a quality finish. 

Think of preparing your walls as tuning an instrument before playing it, fine-tuning it for the best quality performance. That’s exactly what preparing your plastered walls before painting will do!

Here’s all the prep work you need to complete on a plastered wall before applying paint:

  1. Cover any furniture or flooring in the room with protective sheeting. Use masking tape along the edges of the wall to give you sharp lines along the skirting boards and ceilings.
  2. The second step is to fill any imperfections in the walls. Take your filler and fill these areas with your filling knife.
  3. Next, you need to seal the plastered walls. You have two choices for sealing newly plastered walls. The first choice is to apply a mist coat of white matte emulsion watered down (by 50%). Alternatively, you can use a primer to seal the newly plastered surfaces. The sealant can be applied with either brushes or a roller.
  4. The final step is to sand down the plaster walls. I’d recommend using a 180-grit sandpaper for the job.

Painting Plaster Walls

Now that you’ve prepared your walls, you’re ready to channel your inner decorator and get to painting your newly plastered walls with precision!
Follow these steps to get the best paint finish possible:
  1. The first step is to cut in your walls. To cut in your walls, load your angled paintbrush with paint and position it at the edge of the wall, leaving about a 2cm gap between the walls and ceilings. Apply the first stroke of paint across the wall from this point. Without loading up with the brush with more paint, apply the second stroke of paint straight across the edge of wall, leaving no gap. 
  2. After you have cut-in the edges of the walls, you are ready to roll the rest of the surface. When painting with your rollers, apply the paint in either an ‘M’ or ‘W’ pattern. 
Male decorator using a brush to paint a newly plastered ceiling

Can i Paint Plaster Ceiling?

Just like your walls, painting a newly plastered ceiling is absolutely possible. You can follow the above steps, simply substitute walls for ceilings and voila!

But again, you need to wait before painting until the plaster is dry.

Newly plastered walls with plaster that is still wet

What Happens If You Paint Over Plaster That Is Not Dry?

If you don’t wait for the newly plastered wall to fully dry before painting, it can ruin your paint finish.

Let’s look at the issues you’re bound to face if you don’t let the plastered walls dry before painting.

Painting new plaster that isn’t fully dry will prevent the plaster from ever drying properly. That’s because the coats of paint will act as a barrier that stops the plastering from drying. When this happens, it results in trapped moisture beneath the layer of paint, causing mould or mildew growth on the walls.

Also, the trapped moisture will really affect the quality of the paint finish. For instance, it will result in the paint drying at different rates on the surface, leading to visible streaks and patches on the painted surface.

Not only that but when you apply paint to plaster that hasn’t dried, it can cause the plaster to soften. As a result, the plaster will deteriorate, and you’ll probably need to make repairs or replaster the walls before painting.

As you can see, it’s crucial to let the plastering dry before you decorate!

What happens when you don't mist coat a newly plastered wall before painting

What Happens If There’s No Mist Coat?

When you try to paint new plaster without mist-coating your walls and ceilings, you will quickly find yourself in a DIY disaster.

For example, when walls are not mist-coated before painting, the paint doesn’t adhere to the surface properly.

That’s because fresh plaster can be super porous. If you apply paint to a porous surface, the plaster will absorb the water in the paint without covering the wall. When this happens, the paint finishes tend to flake, crack, and bubble over time.

Also, if you don’t mist coat before painting plaster, you will end up with an uneven top coat of paint with patches and streaks on the walls.

So, if you want the same professional finish that painters and decorators can achieve, apply one coat of primer to your plaster before painting.