Natural Holmes – Canadian Contractor Magazine
By Mike Holmes
It’s refreshing when you get a chance to work on something unusual and creative—a type of building foreign to most Canadian streets. I was lucky enough to be the white helmet on a straw-bale home for a customer in Oakville, Ont., that was both creative and enlightening. From top to bottom, it was a labour of love for the owners and me. The idea to build using straw bale came from a trip they took through the southern U.S. When they came back, they wanted to find a way to carry some of that southern atmosphere into their home, and straw bale, with its adobe-type look and excellent insulation properties, seemed like the perfect choice. Not only does it reproduce the style they fell in love with, but it also meets the demands Canadian houses must endure every harsh winter.
I say it was a labour of love, but managing a project as different as this—in an up-scale conservative neighborhood — was another matter. The neighbours were less than thrilled about the design. One woman went out of her way to let the owner know she hated that he was imposing an architectural style on the street. And the building inspectors, unfamiliar with the construction methods, were a tough crowd to please. Lesson learned: if you ever intend to build using unconventional materials or a building process outside of the mainstream, you must thoroughly understand what you are doing, be prepared to defend your choices, and have the right people in place to help you in time of need. In my case, Ben Polly of Harvest Homes in Guelph, Ont., provided the required expertise to see this project through the “straw bale” stage.
Straw-bale building is a 250-year-old technique, yet it has incredibly positive properties. What I like most is that the house actually breathes, a departure from today’s trend of locking houses as tightly as possible and then using some mechanical means to manage air exchange and moisture. At the same time, the walls are R40, which means they beat any efficiency standard you’ve got.
There are a few misconceptions about straw bale—that the straw attracts mice, is a fire hazard, and will deteriorate over time. Here’s the truth: there is no feed in the bales and the straw is inert. In other words, once it is wrapped in chicken wire, lashed together, and stucco is applied to the outside, no changes take place within the walls. A straw-bale house will last as long as any conventionally built house, and, because the bales are packed so tightly, they are actually fire-resistant; even if you could light them, there wouldn’t be enough air for a fire to ignite.
But the owners didn’t stop with straw bale. They also included a number of innovations that I think make this house a design leader worth looking at.
The inspector wasn’t so sure about the Form-a-Drain system, so after the pour I provided extensive documentation to reassure her that the system is legal and approved in Canada. I love this system because it eliminates the need for weeping tile, provides drainage under the slab, and is easy to install.
I don’t know why every basement isn’t built from ICFs. You get as much as R48 insulation value, which makes the basement a comfortable dry space, plus the exterior foam creates a thermal break, there are no forms to strip after the pour, and the basement is completely waterproof. ICFs are well worth the cost.
PEX plumbing line
Here is another new product that should be in every home. We ran this PEX piping “home-run style,” which means each outlet runs straight back to a shut-off panel. There is not a single joint throughout the house. The homeowner had a flood in his last home when a copper fitting let loose, so he jumped at the idea of a no-joint system. It’s not easy to “home run” PEX because you have to pull it through the house in full lengths, but for safety and trouble-free plumbing, it’s the best way to go.
TimberStrand flooring and beams are easy to work with, and come in any length you need. TimberStrand brought us way above code. But what I like best about the product is that it is made from two weed trees – aspen and poplar – which take half as long as pine to repopulate. Environmentally, TimberStrand is the way to go.
We built the fireplaces in the New Mexico style. Called Kivas, they sit on two-feet-thick circular pads cantilevered over the house’s foundation wall. Steel-stud framing define the cone-shaped chimneys (right). We placed insulation between the studs, ran clay flu tiles inside, and then covered the assembly with spray foam insulation. Once the foam was shaped we covered the outside in stucco and the mason built the firebox. The cost was far above a typical fireplace, but the homeowners were not going to compromise the style with a typical brick chimney. Good for them.