Re-roofing the elaborate McMichael Gallery was a project that demanded extreme attention to detail. Housing priceless Canadian works of art, project designers faced the task of ensuring the roof would not be vulnerable to moisture-related problems.

The McMichael Gallery is nestled on 100 acres of beautiful conservation land, 30 km northwest of downtown Toronto, in Kleinburg, Ont. The gallery was founded by Robert and Signe McMichael, who began collecting paintings by the Group of Seven and their contemporaries in 1955. In the early 60's the McMichaels opened their home and gallery to the public and in 1965, donated their home, property and collection of 194 art works to the Province of Ontario. Today, the McMichael welcomes close to 160,000 visitors annually.

With aesthetics and durability in mind, architect Martin Gerskup, Building Envelope Science and Technology (BEST), specified Number 1 grade, 24-inch Certi-Sawn Western Red Cedar Shakes.

The Certi-Sawn Shake resembles a cedar shingle, but is generally thicker and has a larger exposure to the weather. They combine the elegance of a shingle with the heavier shadow line of a shake.

The project involved the 100 percent replacement of the original cedar roof in complete conformance with Cedar Shake and Shingle Bureau (CSSB) requirements.

Utilizing a high-quality Western Red Cedar, fastened with the most durable nails, innovation played a key role in the design of the new roof.

Not only did Gerskup want to provide a solid backing for the shakes, he needed to ensure the roof would not be affected by moisture-related problems.

In addition to completely re-sheathing the roof and applying Grace Ice & Water Shield, a unique thermo-plastic ventilation system from the American Wick Drain Corporation was also installed.

"When I was researching ways of completing this roof, we came across the product from AWD," Gerskup said. "We were only going to use it at the ridge - for ridge venting - but when we started getting into the nuances of the project and the budget, we came up with the methodology of using it over 100 per cent of the new sheathing to ensure the cedar would have the ability to dry out. It was a unique add-on to the traditional cedar detailing."

The CedarSaver ventilating underlayment system is specifically designed to protect and enhance premium wood shingle and shake roofs and siding. Its specially designed cone-shaped dimples allow air and moisture to freely migrate out, thereby lowering the harmful build-up of moisture trapped under wood shakes or shingles.

Avenue Road Roofing, the contractor for the project and member of the Cedar Shake & Shingle Bureau (CSSB), began work on the gallery in August of last year. Having completed work on two major sections of the roof, the company expects to complete the gallery roof by the end of May this year.

According to Ron Turnbull, a partner at Avenue Road Roofing, the greatest challenge faced with the project was the original estimating of the complex roof.

Employing two estimators with a combined industry experience of GO years, Turnbull said the company obtained the gallery plans in order to have the exact measurement of each roof detail- including valley dimensions, ridge dimensions and runs from eave to rake.

"I believe of all the contractors bidding on this job, my measurements were the most exact," Turnbull said.

By duplicating the plans for estimating purposes, the contractor verified that the measurements were to scale by conducting actual field measurements.

On-site, Avenue Road Roofing also faced the challenge of working around the gallery's schedule.

"The gallery had to be perfect at all times and we had to work around their schedule," Turnbull explained. "There were often days when we couldn't work because the gallery was busy or we could only work in certain areas. We knew that going in, and we worked accordingly."

The Certi-Sawn Western Red Cedar Shakes were purchased through Spar Marathon Roofing Supplies from Watkins Sawmills Ltd. - both of which are also members of the CSSB.

Turnbull said Avenue Road Roofing has had a long, working relationship with Spar Marathon so it was fitting to price the project through Spar. As well, since Spar has vast warehousing facilities, the contractor didn't have to ship large amounts of product to the gallery and secure it there, Instead, Avenue Road Roofing was able to order the amounts the amounts they required on a weekly basis.

"Spar is excellent," Turnbull said. "They have really skilled delivery people who were able to back their trucks up around tight corners and place the material in a location that was convenient for us."

Another key player in the project was Don Fry Scaffolding Service, who provided Avenue Roofing with the elaborate scaffolding required for the job.