New code for seismic building in B.C. affects sliding door installations

By David Godkin

B.C. Correspondent

Installing retractable doors and long sliding glass walls to utilize more outdoor space and expand indoor living space are part and parcel of the renovation business in Greater Vancouver. Now, new seismic requirements are making these harder to engineer. Support beams are coming under particular scrutiny, says Mark Cooper of Shakespeare Homes and Renovations in North Vancouver. ‘They’re going to make sure you make sure that beam originally spec’d in that 1950’s home is now supersized to meet the new code, e.g. snow load, seismic wind code, etc.”

Adds Cooper, contractors are not happy about this because their clients are not happy: for every hour a journey carpenter “is standing around, it’s costing the customer sixty bucks.” Consultation with the designer and the municipality or engineers drives up the cost even further. “It’s not just the re and re of that beam. It’s all the auxiliary costs that get attached to it.”

Designer Marque Thompson says the problem originates in the decision to build retractable doors or glass walls into an older traditional Vancouver homes in the first place. “The seismic requirement has had quite a dramatic effect on the structure.” His answer: steel and steel seismic panels. Acknowledging the reluctance of framers to mix wood and steel because of their different rates of expansion Thompson says steel “is something we really have to incorporate because it’s the only way to get some of these large open spaces.”

“Steel used to be found in the fancy homes but is now becoming more commonplace in regular, every day homes.” Getting a Nano or Eclipse door to slide requires a stable frame system, he adds, so steel makes a lot of sense. “We’re making it work.”