November 2007You would think that after all these years, exterior insulation and finish systems would be widely accepted in the building industry. But the road to acceptance can be bumpy.
A case in point is in Toronto where plans are afoot to "overclad” up to 1,000 aging residential high-rises. Somehow, EIFS has escaped serious consideration for the work.
The concrete slab towers (12 to 35 stories tall) were commonly put up as rental accommodation in the 1960s and 1970s throughout the Greater Toronto Area. The problem is today they are energy hogs and in various states of disrepair.
While many critics see them as eyesores that should be torn down, a group called the Tower Renewal Project has big plans for them. The TRP claims the towers have up to 100 years of useful life ahead of them—if they are properly retrofitted and maintained.
High on the TRP’s priority list for retrofits is the application of an overcladding (metal cladding is the preferred medium) and exterior insulation. One of the tower renewal’s leading proponents is Graeme Stewart, an architect with E.R.A. Architects Inc. of Toronto. Stewart doesn’t see EIFS as an option though.
"It is a high maintenance product, relatively speaking. A six-story terrace building is one thing but you can imagine a 20-story high-rise needs a proper maintenance schedule to keep it from looking pretty dated in 10 years.”
Executives of the EIFS Council of Canada might have expected to hear those kinds of negative comments about their product 10 or 15 years ago, but today they are surprised by the dissing.
"That kind comment has put EIFS people on the defensive,” explains John Garbin, president of the council.
He points out that the two metal cladding systems that Stewart promotes for overcladding the towers have no historical precedence in Toronto: "They are the new kids in town. EIFS has a proven 20-year-plus history in both low-rise and high-rise markets.” And it continues to set new standards. For example, Toronto’s Lido Wall Systems is applying EIFS to a 50-plus story tower in Mississauga, west of Toronto.
"Would an owner approve EIFS on a super tower if he thought it would only last 10 or 20 years?” Garbin asks.
Peter Culyer, manager of marketing and technical services, Dryvit Systems Canada, points out that EIFS can beat the two metal cladding systems on price, and it is very energy efficient. Moreover, it has longevity on its side—history bears this out. Just look to Europe—especially in freeze-thaw climates similar to Toronto’s (take Germany, for instance) where EIFS has made a case for itself for more than half a century. It’s even been used as overcladding there for years.
Culyer and Garbin raise another point about the TRP. Stewart advocates the use of a 6- to 10-inch plenum space between the overcladding and the original concrete walls to allow for such services as the Internet, gas lines and future telecommunications connections. He suggests individual metal panels could be quickly removed to access plenum infrastructure for maintenance and upgrading.
But Culyer says the plenum could act as a firechase in much the same fashion as an elevator shaft does during a fire. A plenum space is asking for trouble also from a thermal performance point-of-view, unless the air space is tightly sealed—a difficult proposition in a 35-story tower.
Both Garbin and Culyer point out that the EIFS industry has "done all the research” regarding fire performance in tall towers and should be considered as the main system for the overcladding project.
The EIFS Council hasn’t made a formal proposal to the TRP group, but that day will come as the renewal project starts to unfold. Stewart hopes to see overcladding and other retrofits to the aging towers start in earnest within the next few years.
About the Author
Don Procter is a free-lance writer in Ontario, Canada.