Why is my paint bubbling? How to fix it properly

We’ve all been there. You’ve just finished decorating, everything looks lovely, but a couple of weeks later you spot bubbles starting to appear beneath the paint. Not exactly what you had in mind.

After all that time spent, the last thing you want is to have to do it all over again.

There are a few reasons paint can start bubbling and it’s something we see for a number of different reasons. Whatever the cause though, the important thing is working out which one you’re dealing with because painting over the bubbles won’t necessarily stop them coming back.

We’re going to cover:

• What does bubbling paint look like?
• What causes paint to bubble?
• How do you fix bubbling paint?
• How can you stop bubbling paint from coming back properly?

What does bubbling paint look like?

Bubbling paint is exactly what it sounds like, usually looking like small or large bumps that start to appear under the surface of the paint.

Sometimes it can only be a few small blisters but other times paint can begin to lift away from the wall if the bubbles are large enough.

The most common areas that you might spot bubbling paint in your home could be:

• Around windows
• Behind furniture
• In bathrooms or kitchens
• On ceilings

These are all areas where condensation can build up.

Even though this might seem like a cosmetic issue, bubbling paint can be a sign that moisture is trapped. If this is untreated, the bubbles can burst, crack or peel away.

So, before getting the paint brush back out, it’s really worth working out what’s caused those bubbles in the first place.

What causes bubbling paint?

Moisture in your walls

For paint to adhere properly, your walls need to be clean and completely dry. If moisture gets trapped behind the paint, it has nowhere to go, so it pushes against the surface and creates bubbles.

This moisture can come from:

• Condensation
• Damp walls
• Small leaks
• Painting before the walls fully dryCondensation

Condensation

Condensation can be a big contributor to bubbling paint, particularly in rooms where moisture regularly builds up on colder walls.

Everyday activities like cooking family meals, taking showers or drying clothes indoors all add moisture to the air. When that warm, damp air touches a cold wall, tiny droplets of water form on the surface.

Over time, this repeated build-up of moisture can cause paint to bubble and peel, while also creating the perfect conditions for mould to grow.

Poor surface preparation

If the surface isn’t properly prepared, the paint may struggle to stick, making it more likely to lift or blister later.

Some of the most common causes include:

• Painting over dust, dirt or grease
• Applying paint to damp walls
• Painting over loose or flaking paint
• Skipping primer on bare plaster

Taking extra time to prepare your walls properly will help create a smoother, longer lasting finish.

How can you tell what’s causing your paint to bubble?

Not sure what’s behind those bubbles? Even without too much experience, there’s a few clues worth looking out for that can help you find the cause of your problem.

• Bubbles appearing really shortly after decorating? This could point to poor preparation, moisture in the wall when you painted or an issue with how the paint was applied
• Bubbling alongside damp patches or staining? Moisture could be getting into the wall, either from an internal source like a leak, or an external source like penetrating damp
• Bubbling alongside black mould? Mould and bubbling paint can both be linked to excess moisture, particularly in rooms with poor ventilation, behind furniture or in rooms that don’t get heated as much as others
• Bubbles appearing around windows or on colder walls? Condensation could be contributing, particularly if you’re noticing large amounts of condensation in the mroning
• The same patch keeps bubbling? That’s a good sign the underlying problem hasn’t been properly dealt with

These clues won’t always tell you exactly what’s wrong, but they can help you work out what to investigate further before you do anything else.

How do you fix bubbling paint?

Before repairing the paint, it’s important to identify what’s causing the problem.

Once you’ve identified and dealt with the cause, here’s how to repair the affected area:

1. Remove any loose or bubbling paint
2. Allow the wall to dry completely
3. Repair any damaged areas with filler if needed
4. Sand the surface smooth
5. Prime where needed with a a suitable primer on bare patches or repaired areas (this is often missed)
6. Repaint the area – If condensation has been a problem, maybe think about using a paint designed to help reduce it, while it’s always important to follow the recommended number of coats and drying times of any paint you use

If moisture remains trapped within the wall, the bubbling is likely to return regardless of how carefully you repaint.

How can I stop paint bubbling from coming back?

Ultimately, you want to prevent the problem before it starts.

If the issue was poor preparation, the fix is fairly straightforward. Just make sure your walls are clean, dry and properly primed to give the next coat a much better chance than the last one.

Fixing bubbling paint is only half the battle, because if moisture is causing it and isn’t dealt with, there’s a good chance the problem will return.

If water is getting in through a leak or another damp problem, you’ll need to deal with that before redecorating.

If condensation is the problem, there are a few steps you can take to stop this happeneing again.

The first goal is to reduce the build up of moisture with a few simple habits like opening windows and using extractor fans to let the moisture escape easier.

But it’s not just about the moisture in the air. The temperature of your walls matters too because condensation is more likely to form on colder walls.

That’s where paints like Heroes Shield can help. By absorbing and holding onto the heat already in your home, they help keep the surface of your walls warmer, reducing the amount of condensation that forms.

With less condensation, your walls stay drier, making them a less welcoming environment for mould and helping reduce the moisture that can cause your paint to bubble.

Final thoughts

By now, you’ve probably noticed there’s a bit of a theme to our advice. The best way to stop bubbling paint coming back is to understand why it happened in the first place and take small steps at each point to reduce the risk of it happening again.

Whether it’s poor preparation, damp or condensation, dealing with the cause before picking up your paint brush again will give you a much better chance of getting a finish that lasts.

Still scratching your head over what’s causing those bubbles? Sometimes it’s easier just to talk it through with someone isn’t it?

We’ve got a friendly technical team here at Heroes who know a thing or two about paint and are always happy to help you work out what to do next. Give us a call on 01254 936151 or drop us an email at [email protected] and we’ll be happy to have a chat.

Frequently asked questions

Can mould cause paint to bubble?

Mould doesn’t directly cause paint to bubble but the damp conditions that allow mould to grow can also cause paint to blister and peel. If you’ve noticed bubbling paint alongside mould, excess moisture is usually the real cause. Tackling the moisture problem will help stop both from coming back.

Why does paint bubble in bathrooms and kitchens?

These rooms produce the highest levels of moisture from showers, baths and cooking. Without proper ventilation, condensation regularly forms on colder walls, increasing the risk of bubbling paint and mould.

How long should I wait before repainting after fixing bubbling paint?

Make sure the wall is completely dry before repainting. Painting over damp surfaces can cause the same problem to return, so it’s important to resolve the source of the moisture first.