One Hundred Years Ago, Thomas Edison Built Houses Out of Concrete

©. Google Street View, Montclair concrete house

The housing is in flux; in China they are 3D printing houses out of concrete and in North America and Europe they are building high-rises out of wood. A hundred years ago Thomas Edison tried to mass-produce houses out of poured concrete; that google street view above is one in Montclair, New Jersey. Rebecca Onion writes in Slate:

Edison’s idea: a house that could be built with one pour of cement. The process could eliminate not only the traditional work of erecting walls and roof but also much of the labor involved in finishing the interiors. Given the right mood, “stairs, mantels, ornamental ceilings, and other interior decorations and fixtures” would all be formed by the same giant piece of concrete.
Patent drawing

US Patent 1219272/Public DomainUnlike how concrete is usually poured today, floor by floor, Edison did it all in one shot. Reading the patent issued in 1917, the process is described where the mold or formwork is built of a double wall of cast iron sections held together by bolts. It is all done in one pour, slowly enough so that the concrete at the bottom is hard before the pour reaches the second floor so that there is not that much pressure on the lower parts of the form, which makes the formwork less expensive. “ An important feature of my invention consists in so regulating the rate of pouring the cement into the mold, ‘taken in connection with the hard-setting used.”

Unlike modern construction, everything was built into the formwork; “all its parts, including the sides, roofs, partitions, bath tubs, floors, etc, being formed of an integral mass of a cement mixture.”

Edison with model

Edison with model/Public Domain

According to Adam Goodheart, writing for Discovery,

Concrete homes, he [Edison] said, would revolutionize American life. They would be fireproof, insect-proof, easy to clean. The walls could be pre-tinted in attractive colors and would never need to be repainted. Everything from shingles to bathtubs to picture frames would be cast as a single monolith of concrete, in a process that took just a few hours. Extra stories could be added with a simple adjustment of the holding forms. Best of all, the $1,200-dollar houses would be cheap enough for even the poorest slum-dwellers to afford.

Alas, that formwork was expensive, “nickel-plated iron forms containing more than two thousand parts and weighing nearly half a million pounds. A builder had to buy at least $175,000 in equipment before pouring a single house.“ That’s a lot of money even today in a business where all you really need is a nail gun and a magnetic sign on your truck.

Edison also developed a lightweight concrete mix that he was going to use for furniture, including bedroom sets and even concrete pianos. This, fortunately, never caught on either; when designers tried to bring it back a few years ago I wrote that we should nip this design trend in the bud.

See also Archdaily.