When the roof is bricked, why don't the bricks fall without support? What is the principle?

This has a lot to do with the structure of the roof. When bricklayers need to build a roof with bricks, they generally don't directly build it into a plane, but pile it into an arch or pyramid shape, or pile it with bricks, or squeeze and embed it with arches, which requires bricklayers to have skilled technology and rich experience, otherwise it will be difficult to complete.

In the future, bricklayers need to calculate the area of the roof and the ratio of pressing bricks, but this method is not suitable for that kind of large-area roof. Usually, the roof built by this method will have some edges and corners, which are somewhat similar to the Mayan pyramids and are stepped, like some European brick houses. This method is often used, but it is not particularly common in China. Due to the influence of region and climate, the domes of most houses in China are shingle structures.

The mutually squeezed arches and the inlaid domes test the skills of bricklayers, which is different from the method of piling up walls and cannot be completed in one day. Bricklayers need to calculate the roof. After the calculation is completed, mix the concrete according to a certain proportion, then spread a thick layer of cement on the edge of the roof, and then stick bricks on the cement. After the cement hardens, paste the second lap and then the third lap. So repeatedly. To build this kind of roof, it is necessary to ensure that the viscosity and hardness of cement are moderate, and the thickness and angle of cement between bricks need to be adjusted in real time to ensure that the bricks at the same level will form an arch after cement hardening.

The construction principle of this kind of wall is similar to that of the ancient China, that is, several bricks form an arch, and the middle is connected with cement or concrete, and the bricks are supported by each other, eventually forming a whole dome. In daily life, igloos like Eskimos and the top of graves in some areas are built in this way.