What Causes Hairline Cracks in Plaster?

Recently, I noticed little cracks in certain places of my wall's plaster. I thus hired a NoBroker painter to fix it. I even questioned him what causes hairline cracks in plaster. He told me that these thin cosmetic cracks result from several factors like poor paint quality, poor paint application, climate fluctuations, and so on. 

He went on to say that the hairline cracks in my wall occurred due to climate variations because it caused the plaster to expand or contract. Moreover, he informed me about a few more reasons and how to fix it. I have included it below for your reference.

What are the Reason for Hairline Cracks in Plaster?

As previously stated, the occurrence of contraction and expansion is the primary cause of hairline cracks in plaster. Paint's constant cycles of expansion and contraction over time occur basically due to variations in temperature and humidity. It eventually weakens the plaster's structural integrity. When the plaster expands, it provides pressure on the surfaces around it, and when it contracts, it separates from them. This constant process eventually leads to hairline cracks

The use of poor-quality paint according to the NoBroker painter, is another factor. He explained to me that paint applied on plaster surfaces that are not good quality will not have the required durability. It eventually results in hairline cracking. 

A lack of patience throughout the plastering process is another cause. Before adding any further layers or finishes, plaster has to get enough time to dry and set after mixing. Nonetheless, it is common to observe that labourers become impatient with the drying process in an effort to finish construction or renovations sooner. It leads to such cracks later.

Cracks can also occur by hurrying during the painting job or by not letting previous coats dry. For example - When a thick paint is applied and the drying time between applications is insufficient, stress is created on the surface that results in hairline cracks.

How can I Repair Hairline Cracks?

Let's look at the simplest method my NoBroker painter recommended for fixing hairline cracks:

• This type of crack can be repaired by the use of high-quality or long-lasting paint, giving sufficient time for paint and cement plaster to dry.

• If your structure is made of concrete, you need to fill the space with something that will adhere to the concrete properly to avoid hairline cracks in the future.

Moreover, if cracks are more than hairline-sized, expanding or developing quickly, then I would suggest to take the NoBroker Home Renovation Service.

I hope you got what causes hairline cracks in plaster.