TSC Global's hypar roof is located next to the light ril tracks, just south of downtown Denver

Evidence of new buildings featuring an innovative and cost-effective roof can now be seen in a growing number of African nations, including Kenya, Rwanda, Tanzania, Uganda, and Sudan, as part of a Roofs for the World initiative.

This roof is called a Thin Shell Composite Hyperbolic Paraboloid, or TSC Hypar, thus the name, TSC Global, which proclaims  the building methodology using this roof has the potential for revolutionizing roofing and construction in the most impoverished and remote parts of the globe. TSC Global executive director, Brad Wells, says that compared to the corrugated steel roof structures seen everywhere in the developing world, TSC roof construction requires a minimum in cut lumber, demands no power machinery for construction, and leaves almost no carbon footprint. In addition, buildings featuring these roofs are significantly quieter in rain and windstorms, and can be earthquake resistant.

Denver-based TSC Global was created to build, promote and fully develop this construction method, with the belief that there is real potential to dramatically enhance the overall quality and affordability of structures used by millions if not billions of people worldwide. It is now focusing on a potential rebuilding program for Haiti.

Photos: Brad Wells, TSC Global

A TSC roof is constructed as follows: an acrylic cement composite is applied to an arched hyperbolic paraboloid shaped cloth that has been stretched across a four-sided pyramid framework using wood or bamboo. When the acrylic and cement composite cures, the product is a far superior roofing alternative to corrugated metal and other roofs, contends Wells.

Even with a final thickness of approximately one centimeter, a TSC Hypar roof is strong enough to hold heavy weights. Hypar structures have been built for decades but the most closely observed demo structure was built in 1996 by habitat pioneer, George Nez, who has worked on United Nations and USAID emergency relief projects. The TSC website reports Mr. Nez’s structure has endured Colorado winds, freezes and thaws of as much as three feet of. In warmer climates, these roofs should last many decades.

Importantly, a venting and circulation system has been added to the hypar roof in hot climates, allowing air and cooking exhaust to escape. The top vent and cap is an important and simple modification, says Mr. Nez. Adding a ceiling and sealing off the attic space will also enhance cooling.

A TSC roof, reinforced with embedded chicken wire mesh demonstrates resilience to failure or collapse, says the TSC website, adding that the lightweight roof can decrease chances of injury or worse in earthquake scenarios, even in the most severe earthquake. Recent work in overall building design by Colorado School of Mines structural engineering professor, Panos Kiousis, suggests that simple wall-embedded cross-braced panels secured to a ring beam, with adequate fastening of roofs to posts, should create an earthquake resistant building, still at low costs.

TSC structures can be constructed easily in the most remote settings with no transport of large building materials or equipment. Wells says his target populations include refugee and post-disaster projects, urban “shantytown” replacement, and general commercial and residential building construction. He adds that a further goal for his organization is to offer training and micro-finance networks.

Taking the roofs-first approach, a kitchen is built in Rwanda. Source: George Nez

On one Denver, Colorado back lot a visitor will encounter an unorthodox-looking roof that just might help meet the housing needs of displaced people worldwide.

The roof, shaped like a hyperbolic paraboloid, was constructed on the ground and then lifted in place by African student builders who wanted to build similar structures in locales like Rwanda and Sudan.

Remarkably strong and weather resistant, this new age shelter contains few structural elements, can be constructed without electrical power, and costs very little money.

George Nez is the developer of this roof system, simply calling it a “hypar roof.” Those familiar with his work – especially those builders in Rwanda and Sudan – fondly refer to this structure as the “Nez roof.” The roof is built using latex-modified concrete that is painted over a mesh backing. A video interview with Mr. Nez can be seen here.

Nez, now in his mid-eighties, once served as planning director for the City of Denver before going to work for the United Nations & USAID to help with large-scale resettlements in Africa, Eastern Europe, and South America caused from emergencies like floods or earthquakes. It was there that he implemented the idea of building roofs-first, a practice that has became his life’s work.

A slurry of latex-modified concrete is applied to thos Romanian roof. Source: George Nez

“The principle of roofs-first is to be able to rapidly, and at the lowest cost, provide shelter so the families can move in and eventually fill in their wall. They don’t have time for a slow process of building up from foundations or traditional walls and wait until they can afford a roof? No. The roof-first process builds the roofs for them.”

The roof is built with latex modified concrete that is painted over a mesh backing. “Latex is the basic element in paint and provides a kind of resilience in concrete, which is incredible.” says Nez, adding that testing on the roofs have been tested by the National Park Service and by the Knott Laboratory in Denver and show from double the normal roof requirement up to four times with resilience to hot and cold.

Mesh on roof structure before concrete is applied. Source: George Nez

Nez holds a sample piece of the roof, approximately one centimeter in thickness. “This is all that’s needed, the thickness; that thickness is sufficient to park a truck on it.” It has a reinforcement core of fiberglass screen. That’s what was put across the open frame first then the cement was simply poured on there as thin slurry of latex modified concrete, sand, cement, and latex and water.

Nez is a graduate of M.I.T. as a master in city planning and holds a Ph.D. in Urban Services Administration from Columbia Pacific University. He also served as a professor of planning at Kansas State University.

Live Green Electronics Recycling Event
March 7, 2009
7:00 a.m. to noon

“Do your part to help the environment by recycling your old television, computer monitor and other used electronic equipment at the “Live Green Electronics Recycling Event” on Saturday, March 7th. This event provides a rare opportunity for residents to responsibly recycle old electronic equipment for FREE, thanks to generous sponsorships from LG Electronics, 9News, Comcast, Waste Management of Colorado, and the City and County of Denver. Electronics recycling is expensive and normal recycling costs average about $25 for a TV and $12 for a computer monitor.

“Responsible recycling of electronics helps to prevent lead and other chemicals from leaching into the groundwater and into our atmosphere. Televisions and computers monitors contain 4 to 8 pounds of lead each, as well as many other metals and toxic materials. Recycling old electronics also saves energy and valuable resources.

“Please note that you do not need to replace your television as a result of the February 17, 2009 switch to digital broadcasting. Only residents using an antenna with their television (either rooftop or “rabbit ears”) will be affected by this change and purchasing a converter box will prevent the need to replace a television. Televisions connected to Comcast cable, satellite or other pay TV services will not be affected. If you choose to replace your TV, take advantage of this one time opportunity to responsibly recycle for free.”

For more information and to find specific drop off locations visit www.9News.com and click on the Live Green section. For more information about recycling, visit www.DenverGov.org/DenverRecycles.