In the mid 1960’s, the animated television series “The Flintstones” was one of the most popular shows, capturing both the adult and children's’ markets. As a result there were many products marketed off that show, most notably lunch boxes and a motorized dinosaur with Fred in his seat, just as he was in his job at the rock quarry. The product that hit our household was “Flintstone’s Building Boulders,” huge Lego-like blocks made from styrofoam. With large lugs that fit into equally-sized holes the light-weight boulders could be assembled to make Fred’s house or, as in our case, a fortress which came in handy when we had fights with our dart guns. My father laughed when I said that we should build our house out of this material.

Twenty-five years later a product hit the market called Insulated Concrete Foam (ICF). Like Fred’s boulders ICF’s fit together in a similar block formation. However, unlike the toy blocks ICF’s are designed to sandwich a layer of steel-reinforced concrete. Studies have shown that there are many benefits over the traditional ordinary stick-built home. Better energy efficiency ranks above the other advantages. Other pluses include sheer strength of the walls, a trait which comes in handy in areas where hurricanes are common and sound dampening.

	How do ICFs work? In a nutshell, ICFs take the place of wooden forms for poured concrete walls and stay in place as a permanent part of the wall. They are preformed foam insulation that comes in either interlocking blocks or separate panels, both connected with plastic ties to hold the form and to hold rebar supporting rods. Because they are left in place ICF’s not only provide insulation and sound barrier but also a backing for drywall on the inside, and stucco, siding, or brick on the outside. The plastic supports also provide anchors to place siding on the outside and drywall on the interior walls.

The Insulated Concrete Form Association claims that four inches of ASTM C 578 polystyrene foam sandwiching a five-inch concrete wall is rated at above R-17 at a standard mean test temperature. Thicker walls can push that up over R-20. As well, air leaks in an ICF home are kept to bare minimum due to the continuous air barriers provided by the foam insulation and the concrete. This means there are absolutely no convection currents within wall cavities as can be found in many older, stick-built dwellings. In addition the concrete in the walls of an ICF home have high thermal mass, meaning that the interior of a home is shielded from the extremes of outdoor temperature. So the combination of high R-values, low air leakage and high thermal mass is believed to account for 25% to 50% energy savings of ICF versus wood or steel-framed homes. This includes air conditioning as well as heating.

Cool Savings:

Heat Savings:

ICF homeowners always remark on how unbelievably quiet their new house is, compared with their old stick-build home. They expect the new-found comfort and energy efficiency, but the peace and quiet – the protection from outside noise – never fails to surprise and delight them. In acoustic tests, ICF walls allowed less than one-third of the sound to pass through ordinary frame fiberglass-filled walls. Add to this double-glazed windows and ample roof insulation you could almost set up a recording studio. So, how does that add up to a better investment? Concrete homes have reputation of withstanding hurricanes, tornadoes and fires, all disasters that the poor stick-built houses can’t claim to resist. Remember the story of the three pigs? That is why some insurance companies offer a discount for an ICF home.

So, how about the cost? The Insulated Concrete Form Association claims “ICFs are so efficient to build with and easy to use, that the cost of building an ICF house is comparable to that of an ordinary 2x6 wood-framed house.” I beg to differ. In 2004 I built an ICF home in Wolfville, Nova Scotia and figured it out to be 10–15% more expensive. But let’s not dwell on that just yet. I do agree with every concept that the ICFA claims. It’s common sense really. However, there is one claim that is glossed over and left to the bottom of the report, and that is the actual construction. Here’s what the Insulated Concrete Forms Association reports. “Although it looks new and different, anyone with construction experience can quickly get up to speed with ICFs. An ideal crew has a mix of concrete placement and carpentry experience. Once the crew has some practice, each ICF-build home requires less skilled labor and less total labor than a wood-framed home. And ICFs are very lightweight, so crews stay fresh through the day.”

In my opinion that’s a little optimistic for anyone who wants to do it themselves. As well, they don’t mention the expensive bracing system that is needed and which many suppliers will not rent out. The main purpose of the bracing system is to provide support from “blow-outs,” where pressure of liquid cement builds up and pushes out at a weak spot where the foam is not adequately braced. The system also provides a platform for the workers to both build the walls and pour the cement. I would suggest hiring a company to do the job and, if you want, ask if you can help out as a laborer. However, after chasing blowouts facing hikes in the price of cement in mid-job and watching the cost of rebar go through the roof – all in a four month period – would I build again with ICF? In a heartbeat. Yes, it is more expensive, unlike the claims of the suppliers, but the other advantages mentioned by the association are true. And with in-floor electric or hydronic heating you can forget other types of fuel and just go electric for everything. Heck, you could even go plain, old baseboard electric and kick the crap out of the heating bill of a stick-built home. And, with the price of energy going up steeply the resale of your concrete palace is sure to rise as sharply. The person that bought my 1700 sq .ft. bungalow claimed a total heating, hot water and electrical bill of $1240 between September 2005 and August 2006.

This all adds up to resale value. And isn’t that what a real estate investment is all about?