Article written by Steve Maxwell, home improvement writer. Originally published in Homes & Cottages magazine (Issue 1, 2017). Republished with permission.
Spray foam performs differently than other insulation products. The high-end performance of spray foam has been a reality for more than 30 years, but there’s something new on the horizon. Code authorities across North America have made it known that energy efficiency standards will rise dramatically in the coming decades, with the ultimate goal of net-zero housing. That’s a level of energy performance where a home consumes no more energy than it produces on site. Is this even possible in Canada? Yes, it is. There are houses in this country right now that are approaching this level of performance, and someday building codes will require net-zero for all new homes. The unique properties of spray foam insulation play a big role in achieving 21st century energy standards, and to appreciate how, here are three key facts.
Fact #1: Spray Foam Seals and Insulates in One Step
When Toronto contractor Reiner Hoyer built his energy-efficiency dream home on the footprint of a 1950s North York, Ontario bungalow in 2010, he relied heavily on spray foam. He moved into his new place in January 2011, and his heating costs that first month were less than $20. If you ask Reiner, he’ll tell you that spray foam was an essential part of success because no other insulation combines near-perfect air sealing properties as well as high insulation values. My own experience backs this up, too.
The first time I specified spray foam was on a project for my parents-in-law in 2005. They had a situation where condensation and frost were developing in an unheated storage area off the side of an upstairs bedroom. Warm, moist indoor air was sneaking past an access door, then cooling and condensing on the underside of roof sheathing in winter. The longer a cold spell lasted, the more frost built up. When it finally got warm outside, the frost melted and ruined the ceiling of the entrance hall below. This happened regularly over the life of the house, some winters worse than others.
Like many people then and now, they were concerned about the safety of building products in their home. That’s why I researched and recommended the safest and simplest option I could find. Icynene is a Canadian company with a spray foam formulation that uses a water based blowing agent (for open cell foams). In my case, the Icynene fix worked perfectly. The combination of air sealing and insulation solved a damaging, ongoing frost problem and energy performance was enhanced safely.
Fact #2: Great Payback
Compared with other options, spray foam costs more, at least in terms of up-front investment. Even people interested in quality sometimes have doubts about paying the double or more higher price tag that spray foam demands. That’s understandable on one hand, but mistaken on the other. When you compare the all-in costs of insulating in other ways, spray foam is less expensive than it seems. More importantly, when it comes to building or renovating, ongoing savings are almost always more important than up-front costs. So why would anyone want to pay
more for a given R-value of insulation? Isn’t all R-value the same? No, it’s not, and real world energy performance is the reason why.
R-value numbers printed on insulation packaging have been determined in laboratories under ideal conditions that involve no air movement. And under conditions like these, all R-values result in the same energy performance. But, homes are not laboratories, and that’s why real-world energy performance can vary quite a bit from one type of insulation to another. As soon as air moves through an insulation layer, the actual R-value drops. The more air movement, the less insulation value delivered. Buildings insulated with spray foam can perform as much as 40 per cent better than buildings insulated with non-foam products installed to the same R-value because foam stops air movement. Depending on the situation, this typically translates into a five-year payback or less on the higher cost of foam. After that, the savings go on forever. The
higher energy prices rise, the more valuable energy savings become.
Fact #3: Licensed Application Works
If you ever get to see a licensed spray foam contractor in action, you’ll discover that this work is definitely a skilled trade. The spray equipment is sophisticated, the ongoing attention to detail needs to be high, and it takes a real knack to spray neatly and efficiently with minimal waste. Mistakes in application cause problems, and that’s why licensing in the spray foam business was created.
PLEASE NOTE THAT FOR ICYNENE - Training and evaluation of licensed installers is certified
through a third-party quality assurance provider.
Licensing goes with a manufacturer’s technical services team that’s always on hand to provide guidance. So exactly what do licensed foam contractors bring to the job? Safety, consistency and economy. The good ones use drop sheets, ensure proper mixing of foam components, and make the framing structures ready for drywall after spraying is done. The bearing surface of studs and ceiling joists need to be scraped free of hardened foam, and areas of excess foam needs to be sawed flat and flush with the surrounding framing members.
Rising code standards, rising energy costs and rising consumer expectations are bringing new technologies and building methods to market. Greater use of spray foam is one of the biggest changes unfolding now, and the way things are going that trend isn’t going to change.
Two Places Where Spray Foam Wins
Rim joists: Every home includes places where floor assemblies meet outside walls. These are called rim joists and they always present an insulation challenge. Since it’s impossible to seal indoor air from leaking into the rim joist area in the usual way using poly plastic, rim joists are the most likely place to grow hidden mold and mildew because of wintertime condensation. Applying at least 3 inches of closed cell spray foam or 5 1/2 inches of low density open cell spray foam on rim joists delivers about R-20 of insulation, but more importantly it seals and prevents
indoor air from condensing against cold framing members.
Cathedral ceilings: There are two challenges here. First, there’s usually little room for insulation when the entire depth of the roof structure is defined by the width of rafters. And second, cathedral ceilings are prone to frost build-up and water damage because they can’t be ventilated.
Spray foam solves both these problems by delivering more R-value per inch than other options while also preventing air leakage and condensation.