I got interested in colored cement when I was renovating a house in the English countryside. One of the rooms was four-poster, and I wanted to paint it cream with a red border; that would look great against the green of the woodwork. But I didn’t like the idea of damaging the ancient timbers by painting over them, so I started looking for alternatives.
I discovered a simple material called “colored cement.” It was made from crushed stone: quartz, granite, marble, and what have you. The colorants came from crushed or powdered minerals as well.
There were two kinds of colored cement. One was a liquid, and had to be mixed with water before use. The other was dry and could be trowelled on. Both kinds were available in very large quantities, so it wasn’t difficult to buy them online or in the warehouse of a building supply store.
I experimented with different colors for my cream walls. But then I realized that colored cement wasn’t just for walls: it could also be used as a low-cost floor covering on kitchen counters and bathroom tiles. The food coloring was too strong to use on furniture, but even diluted with water it worked beautifully as an edge trim on chairs, tables and so on;
There are a lot of different kinds of cement, and they’re all different in their strengths and weaknesses. I like the look of colored cement, so I have spent a fair amount of time researching it.
The basic problems are:
Colored cement makes concrete that has too much texture for some uses, such as floors. Most people don’t realize that colored cement is not the same as colored concrete, which is a product sold by some manufacturers (such as L&G) and which doesn’t usually need to be mixed with cement at all.
Colored cement can create new problems. For example, the pigments used in it sometimes react with iron oxide in Portland cement making iron sulfate – an undesirable substance that can cause staining and other problems in concrete.
Cement is a good example of how you can use coloration to enhance the strength of concrete in ways that are invisible. For example, in the illustration, we show four “ages” of gray-colored cement. We think of gray as a neutral tone. But when it comes out of the mixing plant, it still has the proportions of concrete mixed with other pigments and additives and impurities. Very early in the process, it’s already colored.
We have a whole chapter on “colorants” (page 48) in our book Coloration: From Dust to Designer, which is about all kinds of color enhancement in concrete and stone work. In this chapter we call them colorants but they are also called pigments , and they are also called dye-stabilizers , and they are also called extenders . They are there to make the finished product stronger.
One pigment that was common in concrete mix was iron oxide . It’s not very important for “natural” stone like marble or granite, where most of the color is from white quartz or feldspar . But for colored stone like granite or limestone , iron oxide gives more depth and warmth.
Cement is not just an example of concrete but also an example of a class of materials that require more than one application of colorant.
The most common uses for cement are in concrete, where it adds strength and durability. But the material is also used in paints and stains to provide color, as a filler and reinforcement in such things as plastics, wood, paper and textiles, as a binder for silica sand and glass, as a binding agent for leather and other fabrics, and as a thickener to improve the flow of liquid through pipelines.
Colored cement has been around since at least 1811. The first patent was granted to James Thompson in England in 1848.
If you are interested in coloring concrete, it helps to know what the different kinds of cement are. There are two kinds: portland cement and colored cement. Portland cement is made of rock and water, and takes at least three days to set up. The ingredients for colored cement don’t have to come from the earth and don’t need the time to set up. They don’t take that long to harden either; they are made of sand and water, so they can be mixed and poured within a few minutes.
Fiberglass in the 1950s was a very different thing than fiberglass today. Of course, it had glass in it then, too. But by the 1960s, fiberglass had become a generic term for anything made of plastic that was light, strong, and durable. It seemed to be a kind of magical substance. What is fiberglass anyhow? It doesn’t make you feel good to say it’s “made of glass.”
The secret is that fiberglass isn’t made of glass at all: it’s made of polyvinyl chloride, or PVC. It’s not clear why the name stuck; maybe because if you mix PVC with an oil called polyvinyl acetate, you get something that looks like glass.
When people talk about “weaving”, they mean the practice of making cloth from yarn, and there are many techniques for doing that. The ones I’m going to talk about today are plaiting, braiding, and twining.
Plying is simply weaving two threads together. The technique was invented in ancient Egypt and probably originated with basket-makers who wanted more textile surface for the same amount of cloth. Braiding is interlacing multiple strands of yarn into a rope-like structure. Twining is like braiding but uses three or more strands instead of one or two.
These twining techniques are all used to make different kinds of fabric: cables, then horizontal strips, then vertical strips, and so on. All were invented thousands of years ago. They were not invented by the ancient Egyptians or Chinese or Indians or Romans, though some were certainly inspired by them. The first modern text on weaving using these techniques was written in 1670 by a Frenchman named Theodore de Mayerne, whose father had been a Jesuit missionary in China.