Bricks are cheap. It is the concrete that determines their cost. Concrete is not as abundant as brick-making clay or limestone. But it is more abundant than bricks.
Buildings encourage demand for concrete, which encourages use of cement, which pushes up the price of cement, which in turn raises the price of bricks.
A good deal of the concrete we see in buildings is simply a form of waste. New York City has a huge surplus of cement and is building an enormous new campus on landfill, which will use up a lot of the raw material. But some concrete is still needed to hold buildings up, especially if they are not very tall.
The greatest demand for concrete is for the walls of houses, so that’s where most new buildings are going to be made. The walls of houses are usually made from hollow concrete blocks, which are somewhat easier to lay than solid concrete walls and don’t need rebar to hold them together. They also mix more easily with mortar when you’re making a wall and less easily when you’re putting a floor down.
So it’s pretty easy to make houses with hollow blocks: just make a hole in the ground, dig a hole up through the ground, dig another hole down into the first one and pour concrete in it; then pour sand around the edges. It turns out that this is a great way to meet demand for both houses and cement, since there is no reason why any homeowner needs walls that can’t be put up quickly or easily.
If you want good concrete – strong enough to hold up big buildings without any steel reinforcement –
What cement does is to make a “concrete” out of sand and water, by binding them together with the effort of chemical reactions. The secret is that cement doesn’t really do anything except hold the sand and water together chemically. There’s nothing magical about it.
Cement is just a concrete, after all-that’s what it does. And if you’ve done any architectural work, you know that buildings don’t fall down. Buildings fall down when people stop using them.
If you want to build a new building, then you have to buy cement from someone else. And if you want your children or grandchildren to live in your building, they too have to buy cement from someone else. After all, there’s no point in having lots of bricks lying around if no one can use them.
But Houses don’t just sit on the ground waiting for people to buy them; they are bought on the assumption that they will be used again. A house is bought not because it’s useful but because it’s beautiful-and beautiful things are bought because they’re useful. So buildings must be sold as an investment, not as a necessity. If they were only useful, people wouldn’t have to have as much money as they did to buy them: they could
One way to think about the cement industry is to imagine that it is a “building industry.” Just as no one would design a house without the help of an architect, no one would build a structure without the advice of a building contractor. This is not just metaphor: in fact, both architects and contractors are licensed professionals who must pass exams and gain experience on the job.
When you hire an architect to design or supervise your new home, you are hiring someone with specialized knowledge who is uniquely qualified to advise you about what kind of foundation you will need for your new house, how strong it should be, how much insulation it should have, how tall the roof should be, what kinds of windows and doors you want, etc.
Similarly, when you hire a concrete brick contractor to lay down your foundation-and which one you should hire depends on what kind of foundations your home will need-you are hiring someone with specialized knowledge who is uniquely qualified to advise you about what kind of foundations they should put in your new home.
The fact that builders have professional licenses means that there will be significant differences in the plans they give their clients. Professional planners know enough about construction techniques that they can understand when builders are making bad suggestions. For example: if a builder says
The first use of concrete was as a building material. The walls of ancient Egyptian tombs were made of it. Greek and Roman buildings used it too. It was essential for the construction of the pyramids, and is even still used today in the design of tall buildings.
But the supply of concrete was limited to what was available locally, and so the demand was limited too. There were usually no more than a couple of builders in any one city with enough materials to build anything more than one or two houses at a time.
Not anymore. Modern technology allows us to make cement wherever we want it, and on a scale that can turn whole cities into giant factories. The result is that nearly everyone has unlimited access to cheap housing, and almost everyone wants more.
The fact that bricks are made of concrete and look like bricks is not enough to make them a building product. A brick has to have the property of being able to go into a hole and hold itself up. The word “cement” comes from the Latin for “grains that stick together.” Cement is a substance that will stick to itself and other things, but only in small quantities, so it must be mixed with some other substance that will take care of this problem.
X-rays were discovered by Roentgen in 1895, but it wasn’t much used around the turn of the century until it became clear that X-rays would penetrate many substances, not just glass. As those substances became more commonplace in buildings, they made it harder for X-rays to penetrate them, so they started being used on large scale again. However, very few X-ray machines were available at the time; X-ray technology was just being developed as a countermeasure against insects.
The first effective way to build high-rise buildings was with steel girders. These could support much heavier loads than concrete or wooden frames could handle, but their weakness was that they had no internal structure except what provided rigidity for the floor. Steel girders had
Of course you can build a house using bricks, or a wall using bricks. But what you can’t do is buy a building or a wall.
How could you buy them? The way real estate agents do it is by asking: “Have you ever tried to sell your house?” If they have, they know that the best way to sell a house is to go out and find someone who wants one.
The question of whether you want a house is one of the most important questions there is. And yet it doesn’t occur to us that we might ask it before we build one. There’s no need for it, because we don’t even think of houses as products. They are always free: they are given to us. But if they were not given to us, how would we know whether we wanted them?