[BIFE ENG ver.] History of the facade 2/4

Masonry system

1) Materials

Typical masonry materials (Bricks, stones, mud)

Brick is a very common and popular building material. The brick building is a typical masonry structure. (However, the tall brick buildings that are built today are usually decorative bricks, so we can not call them masonry structures.) Not only bricks but also mud blocks and heavy stones are represented masonry material.

Diverse sized bricks

Bricks, mud blocks, stones. Let's find out what these materials have in common. Don't you think these materials are all "stacking" optimized? Heavy stones, as well as brick houses, were used to build walls. In Seoul, the Hanyang Fortress Wall built during the Joseon Dynasty, it was also built by stacking heavy stones one by one.

If you look closely at the size of the materials, you can see the characteristics of them again. The brick size is about 190mm wide, 90mm long, and 57mm high, making it easy for workers to hold it with one hand. In other words, the size of bricks has been processed and developed according to the construction method of masonry.

 

2) Structure

Load-bearing masonry wall 

We found out that masonry buildings are built by stacking materials. Then let's think about the structural features of the masonry buildings. 

 

As the building is built, various loads will now act on the building. Not to demolish, the building has to withstand the loads that are occurring. The most basic load type, that a building has to withstand, is the weight of the building itself. This is called self-weight(self-gravity).

 

Cross-section of masonry wall

 

The Masonry building uses its solid wall to withstand its own weight. If you look at the cross-section of the Masonry building, you can see that the walls get thicker as they go down, because it has to withstand their increased own weight. On the other hand, the wall gets thinner as they go up, as the weight is getting lighter.

 

3) Openings

 

Windows with lintel

Windows with arch

Making openings in masonry buildings is a matter of caution. As the walls of the building itself are the main structures that withstand the weight of the building and all kinds of other loads, therefore, creating openings can pose a risk to the stability of the entire building. For this reason, the windows of a normal masonry building are relatively small. The bigger the windows, the more unstable the building will be. 

 

Then here's the question. How can we make a hole in masonry buildings?

 

4) Making openings

There are two most representative ways. The first one is to place a lintel on top of the opening, and the other one is to make an arch. Let me introduce two methods one by one.

 

Adding lintel

 

• Lintel:

If you think of a lintel as a solid stick on top of an opening, it will work. In other words, I'll call it a horizontal member on top of the openings. The lintel bears upper loads and then transfers load downward. By distributing the load toward around the opening, we can create the opening on the wall.

 

Making arch

 

• Arch:

The second method is arch. Arches are a wonderful form. The force coming down from the top of the opening is transferred to the bottom along with the shape of the arch. Arches do not require special additional elements to create openings. The well-proportioned form alone can distribute the force well and deliver it to the bottom. Isn't it amazing? Compression forces applied between the arched bricks, make it possible to transfer forces along with the shape.

Because of this efficient nature of the arch, in Europe, where the masonry of stone was the main material, the arch was actively used whenever a large span space such as a cathedral, was needed. It is no exaggeration to say that the construction of the cathedral is a fluent variation of the arch.

 

However, in both cases - the lintel and the arch - it's a "job" to make openings in the building. However, on the other side of masonry architecture, there's an architectural system, in which the openings are "made by themselves". And it's the column - beam system. In the next chapter, we will discuss the column and beam system.