Options for preventative roof maintenance

Open duct penetration.
Open duct penetration.

Although these warranties are included in the price of the roof, they are not free; the owner is paying for them. The cost of extended warranties can vary from a few hundred dollars to thousands, and will depend on a variety of factors including the duration of the extended warranty, roof size, and if the client wishes to purchase wind riders (in excess of the standard 88 km/h [55 mph] in high wind zone areas).

These warranties are not a blank cheque for a new roof, as they come with specific clauses that have to be accepted by the owner before they become binding. One of these clauses includes the statement the building owner will have to maintain the roof and provide proof of maintenance. Failure to do so may result in the nullification of the manufacturer’s warranty.

Frequency and costs

The frequency of undertaking preventative roof reviews depends on the location of the building and the facility’s ‘importance.’ As a minimum, both CRCA and NRCA recommend preventative roof maintenance at least twice a year (fall and spring). Roof membrane manufacturers may have more stringent requirements with respect to the frequency of inspections.

The author advises it is best to conduct additional reviews following significant environmental events, such as flash downpours, extreme wind (including micro-bursts), hail, snow, etc.

While two visual reviews per year are enough for a typical building, the frequency may be increased based on the sensitivity of building use and components within the facility. For example, a water leak in a transformer station may shorten out electrical switching gear, and hospitals may have to take out rooms, as water damage my trigger infection control protocols, while a leak into a data centre may damage servers.

Although there is no standard (with respect to frequency), the author recommends a thermographic roof scan at least once every five years, as it may indicate a problem beneath the membrane that may not be visible during a visual review.

Who can undertake a review?

Walking on a roof can be hazardous, and therefore, property managers/facility operators are discouraged from undertaking roof inspections. In Ontario, the labour ministry requires personnel to have appropriate Working at Heights Training to access a roof, as owners can be held liable if there is an incident and an employee suffers an injury.

The author recommends retaining qualified roofing consultants to undertake these reviews as they are properly trained and knowledgeable about the nuances and typical failure modes of the roofing system(s) in question. Alternatively, owners may also seek guidance from the membrane manufacturer if the roof is under an extended warranty. One could also ask provincial or territorial roofing organizations such as the Ontario Industrial Roofing Contractors Association (OIRCA) for a list of their approved members.


Roofs are subject to very extreme physical and environmental conditions. They are, for the most part, the first line of defense against exterior elements, and, in many instances, the most neglected building element. Roof maintenance does not have to be a very complicated and time-consuming endeavour. With qualified people, it can be cost-effective and go a long way toward extending the life of a roof, as problems can be caught early and properly addressed.

However, failure to conduct proper maintenance will have a significant financial impact should an unscheduled roof replacement be required. In the author’s experience, replacement of the roof on a warehouse facility on the outskirts of a city—where there is appropriate ground storage—may cost between $215 and $280 per square metre ($20 and $26 per square foot), while an office tower located in the city core where materials will have to be taken to and from the roof via elevators may cost $690 to $780 per square metre ($64 to 75 per square foot). These costs do not include borrowing expenses, repairing any damages caused to the interior by leaks, or lost revenue in the event tenants have to be relocated. So, do we keep ignoring the car’s engine oil light?

Ted Katsoris is a practice lead in the Building Science Group of Building Specialty Services at Morrison Hershfield’s Markham, Ont., office. He has extensive experience in the fields of building science and building envelope repair/rehabilitation, as well as contract administration. Since joining Morrison Hershfield in 2004, Katsoris has overseen more than 800 projects. He brings more than 30 years of combined contracting and consulting experience to any project he undertakes. He can be reached at tkatsoris@morrisonhershfield.com.

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