Why latex paint cracks the next day after painting

Wall latex paint plays a very important role in decoration, but it is prone to problems. Recently, while we were renovating, we discovered that the latex paint was cracking the day after it was painted. At first we thought it was the workers' responsibility, but after inspection we found out that the problem actually lay with us.

First, one cause of latex paint cracking is indoor humidity that is too high or too low. Indoor humidity has a great impact on latex paint, especially in summer and winter, when the air humidity is not suitable and may affect the effect of latex paint.

When the indoor humidity exceeds 85%, latex paint cannot be painted. When the humidity is too high, latex paint is difficult to dry and the surface quality will be affected, causing the wall to be easily damaged. Problems such as whitening, uneven color and reflection may also occur. Similarly, latex paint cannot be painted when the indoor humidity is too low (less than 20%).

If the indoor humidity is too low, the latex paint on the wall will dry quickly and cracking will occur easily, leaving many small cracks on the wall.

Therefore, when applying latex paint, you need to pay attention to the indoor air humidity and choose appropriate humidity conditions. If the indoor humidity is too high, you can consider using a dehumidifier to reduce the humidity; if the indoor humidity is too low, you can place several basins of water indoors to increase the humidity before applying latex paint.

Secondly, another cause of latex paint cracking is opening windows too early or ventilating for too long. After painting the wall with latex paint, there will be a peculiar smell in the room. In order to eliminate formaldehyde and odor in the room as soon as possible, many people will open windows to ventilate immediately after painting latex paint. However, this is incorrect.

If you open a window for ventilation immediately after applying latex paint, the indoor air humidity will drop rapidly. At this time, the latex paint has not completely dried, and it is easy to crack when blown by the wind, causing small cracks to appear on the wall.

Under normal circumstances, you should wait at least 24 hours after applying latex paint (72 hours in winter), and wait until the latex paint on the wall is completely dry before opening the windows for ventilation. When opening windows for ventilation, be careful not to open them too wide to prevent the wind from directly cracking the latex paint.

To sum up, there are two main reasons for cracks in latex paint the day after painting: opening windows too early or ventilating for too long, and indoor humidity that is too high or too low.