September 30, 2004

Mechanical Contractors Association of Canada conference

Be wary of mould, expert warns

BY PATRICIA WILLIAMS

STAFF WRITER

SASKATOON, SASK.

Mechanical contractors, like others in the construction industry, should worry about mould growth in buildings, says Pinchin Environmental Ltd. senior vice-president Bruce Stewart.

He told a session at the 63rd annual national conference of the Mechanical Contractors Association of Canada that contractors readily can cause mould growth on projects or discover pre-existing mould during a renovation.

“The recipe for mould is pretty simple,” said the Mississauga, Ont.-based Stewart, whose firm is a national environmental health and safety consulting company. He was speaking at a session on controlling risks and liability of mould in construction.

Mould growth can occur when susceptible building materials are wet long enough to allow spores to germinate, grow and multiply. Spores can be blown in through windows or other openings, brought in by ventilation equipment or tracked in with dust and dirt.

Stewart said common sites for growth include drywall, carpets, ceiling tiles, wood and wood products and any paper products. But mould also can grow on pipe insulation, in poorly maintained mechanical rooms and in air-handling units.

Stewart, who specializes in the assessment and control of health hazards in general-use buildings— particularly indoor-air quality, mould contamination, asbestos and lead— told the session that other causes for concern are the facts that:

•Mould growth is a potential health hazard.

•Regulatory agencies hold contractors and building owners responsible.

•There is a risk of civil litigation.

•Mould remediation is expensive and disruptive.

•Contractors have no insurance coverage for this risk.

“It would have been better for you if the building had caught fire—you have insurance for that,” Stewart said.

A member of the Canadian Construction Association (CCA) task force that this year produced mould guidelines for the industry, Stewart discussed mould growth in buildings, health effects, regulatory requirements, professional standards—and risk reduction.

His tips for reducing risks of mould growth included inspecting for pre-existing mould in renovation projects, adoption of the CCA guide as standard procedure and recommending mould-resistant materials and features wherever possible.

Proper design of heating, ventilating and airconditioning systems is one important design consideration, Stewart said.

Preventative measures during construction include effective material handling, phasing construction to avoid susceptible materials being exposed to wet conditions, drying out of any such susceptible wet materials within 24 hours and training of supervisory staff and trades.

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