Causes of Paint Bubbles, Blistering & Cracks on wall-How To Easily Fix Them

I’m sure you have all had the experience of having a Paint Bubbles on wall. It could be pretty frustrating to deal with, but it is possible to get rid of them. Blisters are a common problem, this mainly happens on exterior wall and causes niceness to the people living in the house.

We are assuming that you are suffering from paint blisters on the wall. So, we will highlight the probable causes of this problem and discuss how we can fix it.

What are the Causes of Paint Bubbles on wall ?

Many factors contribute to this problem. The following are the top ones that may happen to your home.

Painting over  oil based paint

It is possible that blisters will appear on your walls if the paint was applied over latex paint or patches of wallpaper or adhesive. In this can, we can fix the problem by removing and scratching off all the old coating and paint. After then apply the putty, and then prepare  to get a new finish or coat of paint.

Painting on a dusty surface

Dust interferes with the adhesion of paint. As  excess moisture evaporates from the inside, so it pushes the paint film away from the surface, which is poorly adhered and stretches, due to the dust, and ends up forming bubbles.

To prevent additional dust from settling on the surface, it is therefore important to use abrasive sandpaper and clean to remove all the existing dust. The area will also need to be scraped and prepared for re-painting in this case.

Using putty in areas near water

Putty prevents the swelling up of water bubble from inside . Eventually it gets “flashed” and ends up falling apart because it absorbs so much water. The water evaporates and forces the paint to push upwards, creating bubbles.

In most cases, paint bubbling appears on new painted walls  due to the issue of humidity. Painting cannot be carried out until the humidity issues are resolved. In few cases plaster may be require to be redone.

Painting under humid surfaces

Applying slurry can also form air bubbles in humid environments, such as when applied to humid environment. In some cases ,bubble can form on wet surface or when the air is over 85% humid, or after a rain.

Paint without sanding the previous layer

Without sanding  and scrubbing the shiny previous layer, the new paint will not adhere properly and will cause bubbles to appear.

As a result, it will be necessary to  sand it, and then proceed with repainting.

Humidity forms mold growth

Each material that has mold must be washed with chlorine before painting, left in place for 1 hour, and then wash it with a damp cloth. Before applying new layer of paint, it is necessary to dry completely.

Unless you solve the humidity source, you will continue to get eruptions and mold , even with fresh paint.

Painting over crumbling or loose boards

When painting has been done on crumbling or loose boards, blisters are bound to appear. Scraping the plaster and coating completely with a spatula is the best way to solve the problem.

Poor preparation

If the surface has not been properly prepared  and if it is not properly sanded and cleaned, may cause  blistering paint and peeling also.


Hot temperatures (usually over 29oC) or exposure to the sun may cause paint bubbles.

Excessive application of paint or putty

The best results are found when paint is applied in thin, uniform layers, following the manufacturer’s directions. This must happen in order to prevent bubbles to form.

How fix the problem of  paint blistering ?

We should try to understand why the bubbles appear , as we said at the beginning. Since the cause of the bubbles will have to be determined, the solution will not simply include repainting – as in the case of moisture, which requires removing the source of the moisture to eliminate the bubbles.

As a rule, blisters formed on painted walls which originates from an inadequate adhesion between the paint and the wall. Therefore, there are a few tips you can apply in your home to help solve the problem in general. Please see the tips below.

You will need the following items to solve the  bubbles:

– Steel spatula;

– Wall sandpaper;

– Slurry or Alkyd paint;

– paint.

Follow the step-by-step

After separating the materials, you will need:

  1. Use a putty knife or steel spatula to scrape off imperfections and bubbles from the entire damaged surface. The  slurry or  paint should be used to repair very deep holes. Regardless of which slurry you choose, make sure to follow the instructions on the package. 
  2. Water proof the wall after drying the slurry. Prevent appearing of new bubbles.
  3. Apply another layer of slurry to ensure a good finishing;
  4. As soon as the slurry dries, you should sandpaper to smooth out any irregularities. Then use a damp cloth to remove all the dust;
  5. You can now apply a new coating of paint.
  6. In the case of  any problem due to incorrect slurry you need to follow these steps.
  7. Totally remove the slurry from where the blistering is occurring;
  8. Then apply a layer of water based primer for preparation
  9. Fill in the imperfections with acrylic filler;
  10. Begin repainting.


Bubbles may have been caused by humidity, which must be eliminated before repainting. The plaster should be corrected with a 1:3 mixture (cement and sand).

Remove the damaged material, apply a coat of primer, correct any irregularities with the filler indicated for your wall (inside or outside), and then proceed with the repainting.

Be careful, since repainting only in the bubble’s place may result in a different tone!.

The wall needs to be repainted if the color tone changes. There may be slight variations between cans of paint, since the paints mixed in the store are usually mixed by hand.

How to avoid blisters on the walls and other problems?

The walls in your home can also get sick, for example, a cracked stove, a cracked ceiling, mold and even blisters. The best way to avoid these issues is to prevent them from happening.

To paint successfully, you need to prepare the walls, including any new ones. Here are some essential tips.


Newer buildings commonly have plasterboard walls. As a result, plaster paint should be applied before using a primer, because of the presence of loose particles that will adversely affect the paint’s adhesion.

Masonry walls

Is  prepared for painting in three ways:

  1. Use of a primer or sealant for sealing;
  2. Slurry application;
  3. The finishing process (paint or texture).

Sealing primers fill porous surfaces since they penetrate and expand, resulting in uniformity. It is instructed to use on new plaster, concrete blocks, concrete blocks exposed to the weather, and fiber cement.

Sealers improve finishing and enhance the performance of products applied afterward (such as putty, texture, and paint).

The primer is used to strengthen plaster, remove peeling paint, repair damaged crumbling boards, or to add durability to weak walls.

As the particles are fixed into the primer, the surface can be painted. This makes the paint adhere better because it agglutinates the loose particles. Due to this, it should be applied before painting – this will help to prevent bubbling.

What other problems can happen?

Apart from blisters, incorrect painting can cause other problems as well. Here are some of the most common.

Fissures and cracks

When cracks and fissures with openings exceeding 0.5mm are present, they are often structural in origin and the result of inadequate foundation calculations.

A civil engineer can help in this case by assessing the property’s structure and recommending appropriate techniques.

In cases where the cracks and fissures are less than 0.5mm, polyester tape can be applied, which is specially designed for this type of repair and eliminates the possibility of new cracks forming.

Make the surface smooth and hide the polyester after the tape is applied with the slurry. After that, apply a color to your desire.


Needs to be removed from the surface by dilution bleach in water at a 1 to 1 ratio, followed by thorough cleaning.

The paint can only be applied after the area has been cleaned, rinsed, and dried. You should always do this process on a sunny day.


It is a similar problem to bubbles and tends to occur when there is an issue with waterproofing.

Apply a coat of acrylic sealer after scraping off any loose sections with a steel spatula. then wait for the slurry to dry before you proceed with the repair. After sanding, seal with one coat of paint, then paint.


There are several causes for blisters , as you’ve seen throughout this content. It is most common for the paint to adhere poorly . So the blistered part will have to be scraped off and before painted again.

Proper preparation before painting is always the best option for preventing this problem. Consider hiring a professional if you need any help regarding to fix it !

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