What is ferrocement?

Ferrocement is also written as ferrociment, ferrocemento, ferrocimento, and ferrozement.

What about Building Permits?

There is nothing tricky about building permits for structures made of ferrocement or any other building material. Codes set the minimum standard allowed for a permitted structure. This means that most homes are built to the minimum standard the law will allow. All one needs to do to obtain a permit is to have a set of plans with a licensed architectural stamp of approval. It’s as easy as that. Although locating an architect confident with use of the material requires a little persistence it is not impossible.

Food for thought; ferrocement houses pay for themselves more than once per generation (low maintenance and insurance costs). Ferrocement tanks and reservoirs pay for themselves over and over by simply outlasting any other material.

What are the mixing proportions?

The following proportions are dry measure. Three sand to one cement, written as 3:1 (three to one). 2.5:1 is very rich, above 3:1 is less so.

Add water until the consistency is such that a line drawn with the index finger settles only slightly. Draw the line on the surface of fresh mortar, make it 2 - 3 centimeters deep. (1" deep). Examine the speed and fluidity of collapse along the line, also known as "slump." Excess water reduces ultimate strength.

Add dry materials in measured proportion if too much water has been used.

Why is it called ferrocement if it is standard cement?

Much steel rather than much concrete. Ferrocement is sometimes referred to as thin-shell concrete.

It is also called ferrocement because the rich mixture makes it hard, like iron. Fibers such as hemp, jute, flax and cotton can be substituted for steel and sand (see bio-fiber in website map).

How much time is required for it to dry?

Concrete does not dry; it becomes strong chemically, in 28 moist days. If concrete dries before this period it will not reach maximum strength.

Where can I learn more about ferrocement?

This website has a graphic shape section to illustrate engineering concepts with shapes rather than words. The tank construction section contains many techniques which will be useful to everyone, including artist and builder. Each section of this website illustrates or explains from the actual experience of many people. Please contribute additions.

Why doesn't this website sell ferrocement or have advertisements?

The components of ferrocement are sold at masonry supply stores everywhere.

The caretaker of this website has built five ferrocement houses, helped on five or six more, and is the product of a large rural neighborhood. The region has frequent fires and earthquakes and techniques of ferrocement became part of the culture there in the 1950's. Many veterans inspected construction then. They knew ferrocement had helped conclude the war and were eager to assist an indigenous and vital young industry. Artistic and practical were blended. The goal was housing for everyone. Fire, hurricane and earthquake; no problem.

When the veterans grew old and retired, 1980's, they were replaced by college graduates who had studied "government science." Third generation neighborhood businesses were destroyed by the new government employees. They were not familiar with ferrocement and didn't realize it can cost more to engineer than build ("transition you out" was the approximate term used by new government employees) (you will be "transitioned out," in english). The website caretaker is older now and this website passes on what was learned then so it is not lost to the future.

Where did this occur?

In the mountains of Santa Barbara, California. Sculpture, reservoirs, and boats were also products. Inexpensive, fire safe, earthquake safe houses were a specialty.

How did ferrocement help terminate the second world war?

Barges, barracks, buried ammunition storage and many other constructions.

Why is ferrocement engineering so expensive?

Engineers use tables and formulae which summarize the compiled observations of what has stood through the test of time. This does require education and intelligence but does not require much original thought. Though the free and artistic forms of ferrocement structures are stronger than other buildings, they are complicated and time consuming to analyze on paper. Computerized structural element analysis automates this complexity but the software remains expensive. A confident architect can stamp ferrocement plans for permit approval with minimal calculations.

Where did ferrocement come from?

Greek fresco, Roman concrete and the sculptural wire and plaster technique from the time of Michelangelo Buonarroti and Leonardo de Vinci, with modern materials.

Where is ferrocement going?

Organic fibers have again become interesting, as the cost of steel increases. Use of organic fibers as reinforcement for cement is not a new idea, mud and bamboo are very durable, for example. Concrete is still called mud in the building trades.

Traditional ferrocement will continue as a material chosen to create beautiful structures and interesting art.

Bamboo, wood and mud after a hurricane. It survived.