Exposed to the wind and sun for a long time
Because the top floor is exposed to the sun for a long time, the soil expands and contracts when it is cold, and the building materials inside the roof are easy to relax, so cracks are easy to occur.
The concrete is uneven during construction.
It may also be because the concrete is uneven during floor construction, which leads to uneven stress and cracks.
Crack repair method
When cracks appear on the top floor, first check the width of the cracks. If the crack width is not very large, not more than 3 mm, it will not affect the use safety of the house. However, if the crack on the top floor is more than 3 mm, we need to take the method of joint filling or high-pressure grouting to repair it.