Six Toronto Commercial Roofing Tips For New Building Owners

New commercial building owners and managers in the Toronto area, need to consider the fact that roofing assets are an important part of the building envelope as a whole; and are responsible to protect the value of the structure and contents within.

Consider the costs associated with internal damage repairs, business interruption, insurance costs, and maintaining property value; having a determined regimen of roof inspection and roof maintenance, is a prudent action that will result in dividends both in the short term and over the long haul.

As a new commercial building owner, the first step is identification and evaluation of the commercial roofing system, and it’s related components such as drainage systems, exterior cladding, caulking and glazing.

Toronto commercial roofing systems are most typically some form of flat roofing. Commercial flat roofing systems fall into three basic categories. Single ply systems, multi ply systems and coatings.

Each type has their own relative merits, but some are better suited than others to certain environmental or occupational requirements. As an example; restaurants that expel exhaust grease may prefer systems like TPO; which are less prone to breaking down the roof system. Asphalt based systems can be impacted by grease.

Schools and hospitals may prefer systems that are low in VOC’s or that are cold applied, eliminating odourous asphalt or open flame applications.

In the category of Single ply roofing; commercial roofing systems include:

Such systems are applied using either liquid adhesives and or mechanical attachment methods.

Systems such as TPO also involve thermo-fusing overlapping seams using robotic or hand held hot air welders.

Related Content: The Many Benefits of TPO Roofing for Commercial Buildings

Multi Ply commercial roofing systems include:

  • Four ply built up roofing using hot asphalt and organic felts
  • Five ply built up roofing using fibreglass felts with hot asphalt or cold fluid applied
  • Two Ply Modifed Bitumen torch applied, hot asphalt applied or cold fluid applied


  • Epoxy based
  • Asphalt based
  • Elastomeric based
  • Emulsions
  • Spray foam

Such systems are applied by sprayer, or roller applied. Certain systems incorporate the use of reinforced mesh materials or scrim products as part of the assembly.

Such systems are often used to attempt rejuvenation of existing commercial roofing assemblies, used on concrete substrate assemblies such as balconies, or bad access water-proofing details.

Sub categories of identification for Toronto commercial roofing systems, (which may employ any one of the previously described systems); can be described as either PMR ( Protected Membrane Roofs) or Convential.

PMR commercial roofing systems are characterized as having the water proofing system adhered to the substrate with thermal styrene insulation over the top of the membrane. Such systems are usually covered by heavy stone ballast or paver systems. Such assemblies are favoured on hi-rise buildings or where the roof may be used as an outdoor terrace environment.

Conventional commercial flat roofing systems have the thermal insulation layer installed beneath the water-proofing assembly. Poly-isocyanurate insulation is used typically for such assemblies.

Roofing insulation thermal values ( R-factor), vary by the depth of the insulation. Insulation levels can vary from one inch to four inches typically. Commercial roofing systems that are installed over interior spaces that are insulated internally, do not normally require external insulation, and in most cases should not be installed under such circumstances.

If adding insulation when installing a new commercial roofing system; modifications to the perimeter details of the roof are usually required.

Once the Toronto commercial roofing owner/ manager has satisfactorily identified the type of roofing assembly; the next step is to understand what to inspect, when, how and why.

Commercial roofing systems can exhibit leaks for very specific reasons. Most typically causes are as follows:

  • Breaches in the field of the waterproofing membrane
  • Plugged roof drains (internal or external), or related plumbing piping below the roof grade.
  • Breaches at appliance details on the roof such as pipes, stacks, curbs, skylights, roof to wall junctions, roof to entry door/window transitions.
  • Leaks resulting from HVAC equipment or ductwork located on the roof.
  • Animal or man-made damage
  • Environmental causes such as animal intrusion, flooding, ice back up, excessive snow load, man-made damage
  • Void or deficient caulking at metal flashing details, or pitch cones/pockets
  • Condensation /air leakage
  • Poor quality of installation or maintenance.

Related Content: Important Cost Considerations When Installing New Commercial Flat Roofing

What as a Toronto Commercial Roofing Owner/Manager, should I do to establish a routine of maintenance and inspection?

Step One:

Document the current scene. Gather previous roofing contracts, maintenance invoices, system manufacturer warranty documents and blueprints if available. Study the details to determine when the assembly was installed, and or when the roof was last attended to and create an accessible file. Take photos of the roof and all of the previously noted roof details. Add these to the file. Consider contacting the professionals who may have worked on your roof and ask for any documentation that you may not have.

As an example, you may still have warranty coverage if the previous building owner had work done previously. Such information may also be valuable when dealing with insurers in the event of loss and proving due diligence in servicing the roof.

Such documented information will also be valuable if ever selling the building asset. Think of it in the same way one would keep service records on an automobile.

Step Two:

Round up your communication lines relating to the roof. Who was/is the roofing contractor, HVAC contractor, Gas line technician, plumbing/drain contractor, roof system manufacturer?

Document so that you or your designate knows who to call in the event of an emergency. Having a relationship with a reliable firm(s) is worth its weight in gold in times of a crisis.  Preferred service usually goes to an established client for whom there is an existing relationship.

Step Three:

Pay for a thorough evaluation of your roofing and related assets, getting the information in writing with accompanying photo documentation. Obtain any estimates for remedial work or roof replacement.

Pay for a determined inspection regimen which may include performing routine maintenance items like the topping of caulking, cleaning gutter and roof drains. Post winter and or fall, are the best times. Calendar such events.

Often routine work can be performed by a maintenance supervisor within your company provided that ( and this is important); they have fall arrest training and certification, related fall arrest equipment, working at heights training, and the proper insurance coverage to protect against liability. Or simply hire a professional roofing contractor or a certified roofing consultant.

Step Four:

Prepare a budget for short term and long term investment in the roofing assets. Not doing so, is following one self from the inevitable. Too often Toronto commercial roofing owners are shocked to face a roofing emergency and do not have the resources to handle the issue. Think lost rent, revenue, equipment or asset damage, business interruption and unnecessary aggravation. Emergencies can cost premium.

Step Five:

As with most demons, one may struggle with in life; one of the steps in the recovery process discusses the stage called acceptance. Accept the fact that you will typically get what you pay for. This may be true for most things in life. The roofing asset is not the item to be cheap with.Best described; become educated on how to properly evaluate a construction purchase. Often referred to as conducting due diligence, the Toronto commercial roofing owner/manager needs to understand how to evaluate the true value in a proposal for service.

Many clients we have encountered in over forty-five years in the roofing industry, choose services largely based on price. Price is important but more important is receiving quality in the services being supplied. If you think a good job performed by a reputable company is expensive, the experience will teach that receiving a poor job will prove to be even more expensive.

A proven industry fact is that a commercial roofing system that is subjected to routine maintenance will cost less over time, and perform longer because such efforts serve to extend the lifecycle of the roofing system. Large corporations typically commit to this maintenance routine because they understand the value of paying a little to defer paying a lot in the short run.

Step Six:

Commitment. Once one has completed proper due diligence regarding the roof system and the supporting trade vendors required, having documented the current roofing scene, and becoming educated on the ideal roofing scene, unique to their circumstance, environmental and occupational needs; a proper budget may be prepared and phased in over a determined number of years.All that will have to occur is to proceed with the determined plan and relax with the knowledge that the roofing asset will be competently dealt with in the most cost-effective manner over time.

Related Content: Determining When to Repair, Recover, or Replace a Damaged Commercial Flat Roof

To learn more about Toronto commercial roofing systems or how to evaluate a contractor/construction proposal investment, visit or call (416)785-5129