Workers can place concrete on the walls using a hand trowel or by spraying it with stucco-type spraying equipment.
Workers can place concrete on the walls using a hand trowel or by spraying it with stucco-type spraying equipment.

In 2002 Isidro Romero Carbo, an owner of shopping malls, developer of low-cost housing, and investor in electrical generation plants in Ecuador, wanted to find a better way to build concrete homes. His vision was to develop a home building system that would have good resistance to wind and seismic forces, yet be easy and fast to build. From an examination of older ferrocement technology, his experimentation and innovation gradually led to the development of the Walltech system. But by this time, the housing market had slowed in Ecuador so he decided to introduce his idea to Mexico.

Many exterior finishes are possible but in Mexico stucco is a favored look. Walls receive a “scratch coat” and a finish application of concrete.
Many exterior finishes are possible but in Mexico stucco is a favored look. Walls receive a “scratch coat” and a finish application of concrete.

In collaboration with one of the biggest builders in Ecuador, Cesar Baquerizo and Guillermo Jaime, a Walltech company was formed to build and promote concrete homes in Mexico and other countries. Their first task was to provide the necessary testing to satisfy Mexican codes. The government then asked them to build 100 homes in one development in order to understand the system better. Jaime says that since that time they have constructed over 600 homes in Mexico—100 of them were constructed in just 2½ month's time. Their goal is 2500 homes in 2006 and 7000 in 2007. He adds that a 42-square-meter home (452 square feet) can be completed in 11 days for less money than just about any other building system.

Walltech's system starts with slab-on-grade foundations. All their work starts with a vapor barrier. Concrete for the floors can either be placed before or after wall panels are set in position.
Walltech Walltech's system starts with slab-on-grade foundations. All their work starts with a vapor barrier. Concrete for the floors can either be placed before or after wall panels are set in position.

This concrete building system shares many of the same advantages that other systems do for building concrete homes: fire resistance, wind resistance (can withstand winds of 200 miles per hour), impact resistance, seismic (up to 8 on the Richter scale), mold, and termites and pests.

Walltech promotes “self construction” in remote parts of Mexico. They train homeowners and volunteers and help supervise the work. Sometimes they also loan equipment. Many homes are built away from roads, so all the materials are carried by hand to the location.
Walltech Walltech promotes “self construction” in remote parts of Mexico. They train homeowners and volunteers and help supervise the work. Sometimes they also loan equipment. Many homes are built away from roads, so all the materials are carried by hand to the location.

BUILDING A HOUSE IN MEXICO

The Walltech system is engineered to construct homes for any income level and any size—as high as 3 stories without changing the reinforcing system of their standard panel. But the company, which now is headed by Michael Zarebski, decided to focus primarily on low-income housing, which is a high priority in Mexico. The goal for the country is to construct 750,000 contractor-built homes this year. In addition to this number, families build a large number of “self-constructed” homes each year. And when Hurricane Wilma hit Mexico last year, an added 10,000 families went homeless. So Walltech's business plan includes helping the families made homeless by the hurricane to rebuild, promoting their system with contractors to help achieve the national goal of 750,000 homes, and initiating a very innovative program to reach out to the “self-construct” market.

Even in remote areas workers use compactors to ensure that the soil can properly support their home.
Walltech Even in remote areas workers use compactors to ensure that the soil can properly support their home.

The self-construct market involves marketing to regions of the country with few roads, and training families and communities in home construction methods. Because there are many dialects of Spanish spoken throughout the country, their training program makes use of graphic and visual methods for teaching. When people are ready to build their homes, Jaime says they load delivery trucks with everything needed for the construction. Many homes are far off the beaten track so trucks park where the road ends and people carry the panels and materials by hand or on donkeys to the construction location.

CONSTRUCTING WITH THE WALLTECH SYSTEM

Self-construction means that everyone gets involved in all aspects of the work.
Walltech Self-construction means that everyone gets involved in all aspects of the work.

The process starts when Walltech engineers look at plans and engineer panelized walls small enough to transport to a jobsite. The panels are manufactured in a factory setting and consist of two sheets of extruded steel mesh separated by wire trusses welded to the mesh. In the factory, workers assemble the panels and cut the openings for windows and doors. They also install rough electrical and plumbing at the factory in the cavity between the wall surfaces, making them ready for delivery. A typical 24-square-meter (258 square feet) panel weighs about 12 kilos (26½ pounds). When panels are hand carried to the location, the panel sizes must be smaller so that they can be easily moved.