Why Are There Hairline Cracks in Your Painted Wall?

Home Painting Home Repairs

You just renovated your home by painting your walls to get a cozy feel. But after some time, you see hairline cracks appearing on your painted walls! Confused and anxious, you’ve started searching for answers, to no avail. Do not worry; we’ve got you covered with all the information on the causes and how to repair hairline cracks in your paint job. Please read on to learn more!


What causes hairline cracks in your paint at home?

You need to understand how hairline cracks occurred in your beautifully painted wall in the first place. Some common causes are listed below:

  • Improper preparation of the paint surface

When you do not prepare the paint surface properly beforehand, inter-coat peeling and hairline cracks will be inevitable. This is because a rough and uneven wall surface texture will not allow your paint to adhere correctly to it. In addition, your preparation will depend on the type of your wall. For instance, the procedure will not be the same for walls with wallpapers on them or walls that have been damaged. Also, whether you are repainting your wall or not will count. The steps for exterior painting may differ from painting indoors! Even if the surface preparation process is time-consuming, you should not skip it!

  • Aging paint causes cracks.

Did you know that temperature changes and excess humidity cause the contraction of materials used to build your strong home walls? So, it is evident that the paint on your walls expands and contracts according to humidity changes. Your old paint will sometimes give in to this pressure and crack. It is because aging paint lacks the flexibility to contract or expand! For instance, you may notice hairline cracks on the walls of an air-conditioned room or walls exposed to direct sunlight during the day.

  • Using low-quality paint

Another common cause of hairline cracks in your paint is the use of paint of inferior quality. The reason for this is a low-quality paint also does not have good flexibility to withstand temperature changes. Also, low-quality paints do not adhere properly to your wall surfaces, hence causing peel-offs within a short time of application. For example, a friend of mine used a type of paint with a high solvent ratio for his garage walls but was disappointed after seeing the hairline cracks in it a few weeks later. Experts advise us to use paints with high pigments and resin levels for better results. In addition, applying expired paint might be even more disastrous! As you know, too much cost cutting might sometimes cost you more!


  • A poor paint job causes cracks.

It is good to be creative and paint your walls by yourself. But have you ever wondered how your enthusiasm and lack of knowledge might make you rush through the task leading to an ordeal in the end? It is true as a poor paint job is one of the leading causes of hairline cracks in the paint. Some examples of poor painting jobs are:

  1. Not allowing the proper cure of the cement plaster prior to applying your paint.

  2. Applying fresh paint over a previously peeled-off coat of paint.

  3. Not giving enough time for initial coats to dry completely.

  4. Using poor painting methods: applying thin layers of paint or not using the right brushes.

How to repair hairline cracks yourself at home?

Hairline cracks are not difficult to fix. You must follow the steps below to do it:

Step 1: With the help of a screwdriver, remove the loose debris of concrete, paint, or plaster to make the crack bigger.

Step 2: Clean the crack either with a vacuum cleaner or a fine brush. Then, wipe the crack with a damp cloth and wait for it to dry.

Step 3: After thoroughly cleaning, fill the crack with a filler or a joint compound.

Step 4: You have to wait for the area to dry to avoid further cracks!

Step 5: It is crucial to sand the surface for a perfectly smooth and even texture.

Step 6: Now, your repaired wall is ready for painting!


When should you hire painting contractors?

For more serious cracks in your wall, especially due to structural damage, you can call experts for help and guidance. However, if you identify these signs, you need to hire painting contractors to do the job:

  1. The cracks in your wall are rough with protruding sharp points and go in different directions.

  2. Your windows and doors are not closing well.

  3. Sagging ceilings and floors.

You have learned much about the causes of unpleasant hairline cracks on your painted walls. You can also try fixing the cracks yourself if you know the techniques. However, it would be necessary to call a structural engineer for help in case your home has major structural problems. Then, you can hire painting contractors for a perfect finish! Please share your comments below!

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