This article first appeared in the St. Louis Beacon, Jan. 24, 2013 - It looks like cement, feels like cement, even builds like cement.
But the blocks sitting in this northside warehouse aren’t cement, at least not mostly. Some contain as little as 2 percent of the material.
“We’re trying to get down to 1 percent plus a green additive” said David Cackowski. He's the co-founder and president of Renewing Roots, a company created this summer with the aim of making it easy and affordable to build “zero impact” homes -- residences focused on conservation, both in energy systems and construction materials.
It may seem like an audacious goal, but it’s one that seems right in line with an enterprise that bills itself as “the greenest home building company ever.”
“The whole idea is to create low-embodied yet physically durable building materials as replacements for our current materials,” said Cackowski. Low-embodied materials are those that take minimal fossil fuels to mine and transport. For instance clay, which can be found locally, requires little transport and natural curing.
For the Purdue mechanical engineering grad, it all started in 2009 during a visit to California where he was introduced to an adobe-type building material that inspired him to look for a Midwestern alternative. He found the answer in compressed earth block, a mixture of local clay and sand that, when spliced with a bit of concrete, can be made into specially shaped, interlocking, environmentally friendly bricks, which he said are inexpensive, impervious to pests and durable.
The finished product doesn’t even require firing, cures at room temperature and Cackowski said it doesn’t bleed heat as easily as concrete.
“If you are heating up the inside wall of the house, it stores it like a battery so you are actually heating the (wall) temperature and holding it longer to radiate back into the space,” he said.
Moreover the clay itself is essentially refuse, leftover debris from mining operations. Cackowski notes that Missouri clay does not expand easily and is well suited to block making.
“It just so happens that we live in a state that naturally produces a wonderful product that can be turned into (bricks) very inexpensively,” he said.
He said the bricks have a 200-year half life, far better than some other materials.
“Even in a 100-year-old house, [wood] starts to warp and the bugs get at it, the molding, the heaving, the expansion and contraction,” he said of traditional construction. “You don’t experience that with an inorganic product.”
But blocks aren’t the only product Renewing Roots creates. There is also a type of cast-in-place insulation known as cellular lightweight concrete, essentially a type of concrete infused with air bubbles that act as individual thermal breaks, which can then be poured into walls to fit any need.
“You replace heavy aggregate like pebbles and larger size particles in the concrete mix with air and it creates a wonderful insulator,” he said.
There are clay roofing tiles as well as a compressed wallboard made largely from agricultural waste, such as straw, which can be employed for a variety of uses including creating faux wood.
Meanwhile on the energy side of the equation, the company sells everything from photovoltaic systems to water recycling setups to composting toilets.
“Our goal is to create a total turnkey house that we can deliver that’s a model for net zero energy homes,” Cackowski said. “We want to have the occupant produce all of their own energy.”
At present, Cackowski and partner Jeff Schneider are working out of 10,000 square feet of rented space in the back of a Jefferson Avenue warehouse. But the company is up and running and it is already working to build its first couple of houses on land acquired near Fort Leonard Wood. Cackowski said they’ve received initial investment funding of about $130,000 and are looking to find another $200,000 or so. He expects Renewing Roots to see a solid return on investment after about 18 houses.
“That’s really just to get the idea out there and create models so our future customers can see our products in use with data attached to them,” he said.
“I got to go to all these different places and learn all these secrets people have about engineering and learn the science behind how to make things work together so I had kind of a higher-elevated view of manufacturing than most people get to experience,” he said.
It’s all about a new way to look at green, not as a retrofit but as a creation from the ground up.
“I thought, ‘What a wonderful way to translate the green movement into something that can actually take hold instead of just doing something that was feel-good or reverse engineering that was badly designed at the beginning,” he said.
The Detroit native said that’s the key – being able to put together a house from scratch with sustainability issues in mind.
“It’s very expensive to add green features to your house because it’s not solar-oriented to pick up the best sunlight. The pitch of the house, the amount of insulation, all these factors together weren’t considered when they were first built 30 or 40 years ago,” he said. “Now we understand the importance of some of these things and we’ve found a way to use common sense at the beginning. Some of these are unique and forward thinking and some are very ancient technologies.”
On the renewable energy side, Schneider formerly worked in the solar cell industry at MEMC Electronic Materials in St. Peters and is now director of the nonprofit Missouri Renewable Energy, which educates on sustainability issues.
Cackowski, who has studied earth construction techniques in the United States and India, said that he feels sustainability is the future.
“Any engineer will tell you the best way is conservation,” he said. “It’s easier to conserve something than it is to create it over and over again.”