You think this is hurricane safe??
Saturday, June 4, 2005
Earth-friendly Homes: Wake up and smell the Rastra
NANCY HALL ALREADY knew the cost of building with wood. It was written in her newly purchased 20 acres in Quilcene, where logging had long since swept away the ancient forest.
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So a few years ago, as she planted the first of thousands of young trees, she pondered how to build a house that would tread gently on the Earth and keep her safe and secure in her later years.
We’ve been friends a long time, so I’m no longer surprised when Nancy is two steps ahead of me. But I had to scratch my head when she told me what she had in mind.
“You’re building a what?”
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View Image | Steve Shelton / Special to the P-I | |
Using the unique building material Rastra allowed Nancy Hall to add personality to her Quilcene dream home with rounded corners and decorative niches and arches. |
“A Rastra house,” she said. “It’s made from recycled coffee cups.”
As I was to learn, Rastra is a popular brand of insulated concrete form, known in the trade as ICF. Imagine Lincoln Logs made of spongy, lightweight concrete and you get the idea.
A typical Rastra block is 10 inches thick, 15 inches high and 7 1/2 feet long. Since 85 percent of its volume is recycled polystyrene (the rest is Portland cement, curing agents and hollow space), two people can easily heft its 120-pound weight.
“If you can stack Lego blocks, you can do this,” said Rastra distributor Tom St. Louis, owner of Green Depot building materials. “It’s actually less complicated than stick framing.”
The blocks’ polystyrene content serves as insulation. Once the blocks are stacked, the builder fills their hollow channels with rebar and structural concrete. Voila! The result is a home that’s as earthquake-resistant, fire-resistant and sound-deadening as a bank vault. Stuccoed on the outside, plastered on the inside, the buildings are virtually maintenance-free.
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Builder Doug Milholland rounds the edges of a Rastra window frame. |
“I wanted something that will last until after I’m dead,” Nancy said the other day, as we sat gazing out at the riotous cottage garden that hugs her new, Earth-friendly home. “I think that’s what I like best — it feels like a fort. It just feels very protective.”
Nancy had a lot riding on this project. She was well into her 50s when construction began, and she was paying cash. She couldn’t afford to screw up.
She settled on Rastra after deciding that two other alternative materials — straw-bale and cob, or free-form adobe — rattled her anxiety meter. Never mind what the experts said, Nancy had doomsday visions of a paid-for cob house melting in the rain, and of mice and mold feasting on straw walls.
I had my own doubts about these strange plastic-foam bricks. The work site was dreary with winter rain and mud in early 2003, when I got my first look at the newly emerging walls. At that point, it was hard to see the coziness and charm I knew Nancy would demand in a dream home.
Still, I cheered her on as she shared progress reports. Port Townsend builder Doug Milholland of the Blue Heron Construction co-op, an old hand at building with Rastra, worked from a plan devised by Nancy and her former neighbor, Bainbridge Island architect Judy Friedman.
My doubts evaporated when I saw the finished house, with its softly plastered interior, built-in nooks and rounded corners. The house had personality, from its handmade cement-stucco “gargoyles” — a touch Milholland suggested — to the colorful light-catchers Nancy had embedded in the exterior walls…..
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“Have you seen my baseball?”
Replies
Rastra is great for temp control and resists mold. It's also used in places where fires are common, because it's fireproof. ICF usually is a great hurricane choice, but it's more expensive than wood or steel.
Rastra in specific, ICF in general, is really a concrete product. The form is light, but is filled with concrete, so generally very strong.
We've got a structure on the farm out of rastra and it's cool even when it's 95 outside. It's tornado country and the other structures are beaten by 70 mile an hour straight winds all the time, but the kidding shed is always untouched. An unexpected benefit is that the scorpions don't come in!
Let the beauty of what you love be what you do. ~ Rumi
Geez....thought it said "Rasta." Was about to break out my Bob Marley and check out a "stems & seeds" structure....