Michael Holigan: The world's forests continue to be cut down faster than they're replaced. Along with the impact on the environment, that also means that the supply of good, quality wood for building homes is becoming more scarce all the time. As a result, new alternative, building materials and methods seem to be popping up almost everyday. One that might really surprise you combines recycled Styrofoam with concrete. It's called Rastra, and it can be cut and fashioned into almost any shape imaginable with very simple tools. Our first encounter with Rastra was at the National Association of Home Builder's convention. What price range homes do people build out of this?
Richard Wilcox: Low income to very high income.
M.H.: So you don't have to cut down any trees, you can build any size house?
R.W.: That's right.
M.H.: How does it stand up to wind pressure? It feels like a light material, being made out of plastic.
R.W.: Because of the structural core, it is extremely strong, especially in wind application. The University of California Irvine has done extensive testing on this. On a standard 10 inch wall, it takes 84,000 pounds to move it on a lateral sheer.
M.H.: So that's a lot stronger than a wood wall?
R.W.: Absolutely. About 700% stronger than a wood sheer.
M.H.: What do you do for the exterior of this wall?
R.W.: We're able to apply any exterior on the market. The beautiful thing about plaster on this material is we can use the acrylics and we only need an 1/8 of an inch skim coat.
M.H.: Okay. So you can put vinyl, brick, stucco, anything on the outside?
R.W.: Absolutely.
M.H.: Artist and sculptor Cam Schoepp decided to use Rastra to build a large addition to his 1926 bungalow.
Cam Schoepp: A lot of what attracted me was the quality. The thickness of the walls, the insulative qualities.
M.H.: The insulating quality Cam is talking about is an R-Value of 35 or more in the typical 10 inch thick Rastra wall. R-Value is simply a measure of resistance to heat transfer, and the higher the number the better. And our value of 35 is pretty high compared to an R-Value of 13 for the typical wall framed with 2x4 lumber. Rastra's energy saving and environmentally friendly qualities are welcomed by builders, but they weren't the first goal of it's inventors.
Karl Holik: Our main concern was to create a light weight material and we wanted to create something for the do-it-yourselfer, so everybody could build something. The material, besides of it's capability of taking flames, is very easy to work with. Actually much easier than to work with wood. You can cut it with a hand saw. You can scratch it, you can actually sculpture it.
C.S.: It's verging on, to date, the biggest sculpture I've done. A lot of the decisions equate to the decisions I make in sculpture, so a lot of the processes are similar. The blocks weigh about 150 pounds a piece, the single blocks. They also come double wide, but I'm working with only one other person, so we're finding that we have to actually separate the double blocks, cut them in half. We just chain saw them in half and use them as single blocks then. It's pretty quick.
M.H.: Because Rastra is made of recycled Styrofoam cups and packaging, you might think it would burn or melt easily in a fire. But Braun Intertech, an industrial testing lab in Portland, Oregon, recently found it to be extremely fireproof. Flames on one side of the wall brought the temperature up to more than 2,200 degrees for five hours without setting it on fire or causing a release of any gases. Meanwhile, the other side of the wall showed no transfer of heat at all.
K.H.: At the same time as the wall doesn't transfer heat during a fire, it wouldn't transfer heat in cold or very hot areas.
M.H.: Once the Rastra blocks are in place, the honeycomb of holes inside are filled with concrete and reinforced with steel rebar. That's what gives the walls their strength.
C.S.: Another thing that is interesting about this is that, you know, for electrical purposes you just simply run your chain saw into the surface of it and put your conduit in and that's how you set your electrical system. And then it's no drilling through 2x4's and threading wire and all those kinds of things. It's all done two inches below the surface with a chain saw.
M.H.: Cam's addition is nearly completed, and soon his family will have nearly double the living space in their home. He says building with the Rastra was about the same cost, or maybe even a little than using traditional wood framing.
C.S.: The material itself is not wildly expensive. It's pricey, but one has to consider that it takes care of the insulation and the siding. It takes care of a lot of the tasks that begin to add up when you start adding the wood and the siding and the drywall and the plaster, everything that's involved, the insulation.
M.H.: Rastra seems to lend itself to a variety of home styles, since it can be easily milled or shaped on site to accommodate almost any design. It's just one of the emerging high-tech alternatives for building your new house.
For more information on Rastra, feel free to call Richard Wilcox 619-778-6593 or Karl Holik 602-935-3545.
Episode 44 1996 - 97 Season
| Infrared Test | Shower Head Cleaner | Outdoor Safety | Locking Up Valuables | Building with Rastra | The LumberJack | People in the Loan Process |