Painting new plaster can be tricky, but you can achieve a flawless, long-lasting finish with the right technique. Proper preparation is essential, whether updating a fresh wall in your home or preparing newly plastered surfaces.
Skipping steps or rushing the process can lead to peeling, cracking, or uneven texture. In this guide, we’ll walk you through the best methods for painting new plaster—from allowing it to dry fully to applying the essential mist coat—so you can get beautiful, smooth walls that last.
Let’s get straight to the point.
To paint new plaster:
- Ensure it’s fully dry before starting (typically 2-6 days).
- Begin with a mist coat—diluted contract emulsion paint—which acts as a primer.
- Apply the mist coat, let it dry for 24 hours, and then proceed with the topcoat.
- Use the right paint to avoid peeling or mould, especially in humid areas like bathrooms.
- Avoid common mistakes like painting too soon or skipping the mist coat to ensure a smooth, long-lasting finish.
How Soon Can I Paint New Plaster?
Before starting any painting on new plaster, it’s important to ensure it is completely dry. Painting too soon can lead to peeling, cracking, or an uneven finish. Here are the key points to keep in mind:
Colour Indicators For Dry Plaster:
- Wet plaster: Dark grey or brown.
- Dry plaster: Gradually lightens to a creamy pink.
- The plaster is ready for painting once the entire surface shows an even, light pink appearance.
Drying Time:
- The time it takes for plaster to dry depends on the environment (temperature and humidity).
- General drying time: 2 to 6 days.
- Tip: It’s better to wait longer than paint over damp plaster, which can lead to problems later.
When In Doubt:
- If you need clarification on whether the plaster is fully dry, it’s advisable to wait a few extra days.
- Ensuring the plaster is completely dry provides a solid base for the paint, resulting in a longer-lasting, smooth finish.
These guidelines will help you achieve the best results when painting new plaster.
Painting New Plaster Walls: Step-By-Step Guide
Painting new plaster requires some preparation to ensure a long-lasting finish. Follow these simple steps to avoid complications like chalky textures, peeling, or cracks.
1. Let The Plaster Dry Fully
Allow the new plaster to dry completely before starting. Use natural air circulation or heaters to speed up the drying process, but do not rush it. As mentioned, the plaster should be consistently light pink before you start.
2. Apply A Mist Coat
A mist coat is essential when painting new plaster. This primer layer seals the plaster and ensures that subsequent paint coats adhere properly.
To make a mist coat, dilute standard contract emulsion paint with water. Contract emulsion works best for this purpose—avoid using vinyl matte emulsion, as it won’t absorb into the plaster effectively.
Mist Coat Ratios
The dilution ratio varies, but here are three commonly used ones:
- 70% emulsion, 30% water
- 60% emulsion, 40% water
- 50% emulsion, 50% water
The ideal ratio depends on the room’s specific conditions. For example, a 50:50 mix will work best if the room is empty, as it reduces splatter. A 60:40 ratio is a good balance in most cases. For plaster repairs in furnished rooms, opt for a 70:30 ratio to minimise mess.
3. Apply The Mist Coat
Once your plaster is dry, apply the mist coat using a roller or brush. A roller allows you to cover the surface quickly, but it can be messy, while a brush takes longer but results in fewer drips.
If you notice any drips or streaks, paint over them immediately before they dry. Once the mist coat is applied, allow it to dry for 24 hours before moving on to the next step.
4. Apply The Topcoat
After the mist coat has dried, you’re ready to apply your topcoat. This is the final step in painting new plaster, and it’s straightforward now that the base preparation is done.
Use the “V” technique for an even spread—move your roller or brush in a “V” shape for complete coverage. Depending on your desired paint and finish, you may need to apply multiple coats for the best result.
What Is A Mist Coat?
A mist coat is simply a diluted emulsion used to prime fresh plaster. The standard emulsion is too thick for newly plastered surfaces, so diluting it helps the paint absorb into the plaster. The paint won’t dry properly without a mist coat and could peel or flake off. A mist coat helps to seal the plaster, providing a smooth surface for the final layers of paint.
Mixing The Perfect Mist Coat
The mist coat ratio can vary depending on the paint and the environment, but a 70/30 ratio is a safe bet in most cases. If the mixture feels too thick, add more water until it runs smoothly from your roller or brush.
Use a non-vinyl, water-based emulsion for the mist coat, and always check the manufacturer’s recommendations on the paint tin. Diluted paint is messy, so dust sheets protect your floors and furniture.
Should You Apply Two Mist Coats?
While one mist coat is usually sufficient, applying a second one won’t harm the surface. It’s a good idea if you want an extra layer of protection. Follow the same steps as the first coat and wait another 24 hours for it to dry before proceeding with your topcoat.
Common Mistakes To Avoid When Painting New Plaster
Several common mistakes should be avoided when painting new plaster. Avoiding these can save time and effort and ensure a durable, professional finish.
- Painting Too Soon
- The most common mistake is painting before the plaster is fully dry. Here’s why:
- Paint will peel or flake if applied to wet plaster.
- Wet plaster forms an airtight seal under the paint, trapping moisture.
- Trapped moisture can cause mould growth and efflorescence (white, salty deposits on the wall).
- Always allow the plaster to dry completely—waiting an extra day or two is better than rushing.
- Using the Wrong Paint
- Choosing the correct paint is vital for proper adhesion and a smooth finish. Key points:
- Avoid vinyl-based paints for mist coats, as they don’t absorb well into plaster.
- Use contract emulsion for mist coats—it’s thinner and absorbs into plaster properly.
- For high-humidity areas like bathrooms and kitchens, always opt for moisture-resistant paints. This prevents issues like peeling or mould formation due to humidity.
- Skipping the Mist Coat
- Skipping the mist coat is a significant mistake. Here’s why:
- The mist coat acts as a primer, allowing the top layers of paint to adhere correctly.
- The paint will sit on the surface without a mist coat, leading to flaking and peeling.
- Though it may seem like an extra step, the mist coat is essential for a durable, long-lasting finish.
By avoiding these mistakes, you can ensure a flawless finish when painting newly plastered walls.
Conclusion
Painting new plaster can seem daunting, but following the right steps can achieve a professional and durable finish. The key is to be patient—allow the plaster to dry completely before starting and never skip essential steps like applying a mist coat.
Using the right paint, particularly in high-humidity areas like kitchens and bathrooms, will prevent peeling and mould growth, ensuring your walls remain in top condition.
You’ll create a smooth and long-lasting surface by avoiding common mistakes such as painting too soon, using incorrect paint, or skipping the mist coat. With careful preparation, choosing the right tools, and a systematic approach, painting new plaster can be straightforward, resulting in beautifully painted walls that will stand the test of time.
FAQs About Plaster
What Kind Of Paint Do You Use On Plaster Walls?
The best paint for plaster walls is whatever colour appeals to you! Once properly patched and primed, plaster walls can easily take any colour or finish. Satin and eggshell finishes are very popular, and lighter, neutral shades of cream and white are ideal if resale value is a concern.
What Do You Paint New Plaster Walls With?
All you need to do is get some white emulsion paint and thin it out with water – it’s that easy! Three parts paint to one part water should work. If you don’t fancy watering down your paint, use a sealer for plaster.
Will Primer Stop Peeling Paint?
If moisture causes peeling paint, protecting your newly painted area from the same problem is important. Primer can help seal the surface to protect against moisture and allow the paint to stick properly.
How Do You Keep Paint From Peeling Off Plaster?
I suggest sanding and then coating with watered-down PVA glue to achieve a seal over the surface. I also recommend this in the first instance on newly finished plaster to prevent flaking, peeling, or cracking.
Can You Paint Directly On Plaster Walls?
Painting new plaster isn’t just a case of slapping on a coat of emulsion. New plaster gives a nice smooth finish to walls and ceilings, making it the ideal surface for painting, but painting directly onto plaster can cause issues that lead to paint not adhering and flaking off.
