New insulation products save heating costs

Insulated concrete forms (ICFs) use rigid sheets of foam instead of wood to contained poured concrete, and they also create the most pleasant, easily finished basements you'll find anywhere.

When my wife and I and our newborn son moved into a 400 sq.ft. lakeside cottage in September 1990, I had no idea the experience would teach me the first half of a surprising lesson about progress, innovation and home energy consumption. The cabin was stop-gap accommodation, necessary while I completed a 2500 sq.ft. home I was building nearby, and the only source of heat in the place was a kitchen woodstove that had to be fed every few hours around the clock. Even though outdoor temperatures rarely dipped below freezing during the 6 weeks we stayed there, the stove consumed about 1 1/2 wheelbarrow loads of dry, split firewood every day just to keep the tiny place barely warm enough for a baby.

When we finally moved into our new home, it meant a fast trip forward through five decades of house design, and the second half of my energy lesson. I burned less wood heating our modern home at -10C than I did the old cabin at +5C, even though the house was 600% bigger.

The old cottage was well built for it's time, though there's only so much that workmanship can accomplish. As I discovered first-hand, the energy performance of any building is determined in largest measure by design and materials, and that's where new homes and renovations can win the conservation game hands-down. But as astonishing as the new efficiency gains were to me then, the possibilities are even better today than they were a decade ago when I completed the main parts of my house.

A handful of key homebuilding technologies have entered the main stream construction business over the last 10 years, and they offer the possibility for much better homes, lower operating costs, and a healthier environment. This good news story is about homebuilding innovation at its best, though the gains haven't yet appeared in every new home development that crops up. It's also true that houses built with leading-edge energy-saving technologies don't look any different than homes built using conventional methods. That's why you need to know what to look for, what details to request from your builder, and why these make a big difference to your household energy budget and comfort levels.

Based on what I've learned during the last 15 years of writing about building and construction, I'm putting three innovative technologies into practice in a 1,000 sq. ft. workshop/office I've designed and am building right now. I settled on the shape and floor plan of the structure using a scale model built from 3/16-inch foamcore, a rigid lamination of foam and bristol board you can buy at any office supply outlet. Modelling of this sort is a design tool that anyone can use to create a building shape that's pleasing and useful.

Besides offering a more comfortable, economical structure than anything that's come before them, the new methods I've chosen have another spin-off benefit. As the supply of experienced tradespeople decline, two of these new building approaches were developed to rely less on skilled hands. This translates to lower labor costs and better do-it-yourself possibilities for owner-builders tackling project without professional help.

Destination Insulation

If you ever get a chance to grab a piece of rigid building foam with your bare hands in winter, you'll experience an excellent example of why it's such an effective insulator. Foam inhibits heat transfer so well that it actually feels warm to the touch, even though it's not giving off heat. Harnessing the value of foam insulation is what structural insulated panels (SIPs) do best, and energy performance is one reason I chose them for my latest project. There are two other virtues, as well: strength and speed of assembly.

SIPs are factory-laminated, two-part building sandwiches. The inner core of rigid foam (usually made of expanded polystyrene) is typically sheathed on both sides with a wooden sheet material called oriented strand board (OSB). SIPs completely replace the need for wooden wall and roof framing, and offer increased strength and energy performance as they do. That's a hard claim to believe for something made of the same material as a coffee cup, at least until you heft a piece of SIPs for yourself. Though not heavy, the combination of wood and foam creates an amazingly strong and rigid material.

SIPs typically come from the factory in thicknesses of 4 1/2, 6 1/2 and 8 1/4 inches, in panels 4 feet wide. An electric tool called a hot knife is used to recess the foam away from panel edges, creating a groove for connecting strips called splines. These, along with low-expansion injectable foam, strengthen the joints between panels and make them absolutely air tight. Besides the fact that SIPs provide a continuous layer of insulation, it's also easy to make them draft-free.

Although most builders don't currently use SIPs for roofs, there's a sound case to be made for the practice. I expect to see more and more of it. Since SIPs panels have load-bearing strength, they can span many roof situations with little or no wooden framing. Assemble them piece-by-piece over a ridge beam and you've got instant livable attic space, already insulated, sealed and ready to finish. Drywall fastens directly to the surface with screws driven anywhere into the OSB. You can learn more about the Thermapan SIPs I chose for my project. For industry-wide information on this building technology, contact the Structural Insulated Panel Association.

Concrete Solutions

One of the easiest, most economical ways to boost the value of household living space is with a finished basement. You've already got the foundation, walls and ceiling you need. Just make them pretty, warm and dry, then enjoy the space. Insulated concrete forms (ICFs) use rigid sheets of foam instead of wood to contained poured concrete, and they also create the most pleasant, easily finished basements you'll find anywhere.

ICFs are a building option that combines rot-proof strength, high insulation values, and the possibility of terrific water resistance in one package. Many systems are on the market right now, though all work in a similar way. Two layers of rigid foam are held together with an air space between them. This space is filled with concrete to create strength, while the foam remains in place permanently for thermal insulation. When ICFs came on the scene they were used mostly for foundation walls. That's how I'm using them for my shop, though now they're being used above-ground, too.

Even though I don't have a basement in my workshop, I still chose ICFs for their thermal performance. My design includes a heated concrete floor slab, so insulation along the sides of the foundation structure is essential to keep heat in.

Another reason to choose ICFs becomes obvious on rocky building sites where foundation walls rest directly on bedrock. This makes them ideal for cottage projects. Instead of struggling to install a conventional wooden form on an irregular surface of stone, ICFs offer a unique short-cut. Since the foam is easy to cut, it can be scribed and sawn to fit the contours of the stone. That's what I did at my place, sealing the ICF structure to the rock with low-expansion, spray-on foam and rebar anchored into pre-drilled holes. Even if you're installing ICFs on a conventional footing, they go up quickly and easily. I've built the usual sorts of wooden concrete forms before, and ICFs are much easier and quicker to use. In fact, they're so easy to put together that they've even appeared for sale on the retail consumer scene.

The Formtech system I chose is the first ICF option to become available to qualified non-professionals at the retail level. Home Depot stores in Barrie and Orillia carry the product now, with plans in the works to expand the offering to other stores.

Bottom-Up Warmth

Warm your toes, and the rest of you will be warm, too. That's the philosophy behind radiant in-floor heating, an ancient idea that's got a new start through the application of an innovative combination of plastic and aluminum heating pipe.

When heat is distributed through the floor of a structure in a network of pipes carrying water or glycol antifreeze, it's called a hydronic system and I chose hardware made by Ipex to keep my building warm. This is a Canadian company that's made radiant in-floor heating popular worldwide through their WarmRite Floor system. In my case, heat is supplied to the pipes from an oil-fired domestic hot water heater (all you need for small and medium-size buildings) where it's pumped into pipes buried in the poured concrete slab. Pipes also go upstairs, running in channels in the second-storey wooden floor frame. Warm water floor is controlled in different zones by thermostats. Reflective barrier foil directs this heat upwards, through the laminate flooring applied on top.

To get the most out of any hydronic system, the area under a ground-floor slab needs to be insulated, usually with 2 inches of foam providing R-10. Next comes a layer of reflective foil and some steel reinforcing mesh. Radiant heating pipes are secured to this mesh before concrete is poured on top. By creating separate loops of pipe, heat can be directed and controlled differently in various areas of the building. The warmth delivered is smooth, even and quiet, without drafts or moving air currents that kick up dust.

For as long as I can remember, environmental issues have been near the top of my list of perennial concerns. And when it came to managing the planet, I used to believe that primitive simplicity was the way human beings could best coexist with the earth. And while I'm still sure that we need to keep focused on the essentials and do all we can to live happily with less, I've also come to a renewed faith in the value of innovation and conservation technology. My experiences with that woodstove and a brand new baby helped a lot to point me in this direction. Sometimes old technologies and approaches are the most wasteful of all. And with developments like SIPs, ICFs and radiant heating systems, we're one step closer to seeing what a sustainable future looks like.