COMMERCIAL ROOFING

Several factors influence the cost of replacing a commercial roof, but the most significant is the size of the project.

One of the first considerations is the building envelope. For example, how well did the previous roof assembly perform over its life cycle? Has the internal use of the building changed?

Another factor is examining areas with poor drainage, where water may have ponded for years, potentially accelerating membrane deterioration. In such cases, it’s a good time to assess whether there’s a need to remove any unused roof equipment or penetrations. It’s also an opportunity to install new roof equipment if needed.

As a result, a site inspection is necessary to identify and record potential design failures that may need correction. We recommend having a professional HAAG-certified commercial roofing inspector conduct the inspection.

After determining the size of the project and completing the inspection, a roof assembly can be customized for the building. The overall estimated cost depends on the type of membrane, desired R-value, and applicable provincial and federal regulations. Once these factors are considered, an estimate is presented to the client.

The best roofing material depends on your specific project. Each roof is unique, and the recommended application varies accordingly.

Every membrane and assembly component has its strengths and weaknesses. For example, installing a modified bitumen roof assembly on a large, open-concept warehouse may not be as cost-effective as a ballasted EPDM (Ethylene Propylene Diene Monomer) roof assembly. Both options can offer similar warranties and protection against environmental concerns, but the EPDM roof assembly is significantly less expensive upfront. However, the modified bitumen roof is more suitable for roofs with higher foot traffic and frequent equipment maintenance needs.

Flat roofs are popular on commercial buildings for several reasons. One advantage is the ability to place key building systems, such as HVAC units, on the roof. This frees up interior space, allowing for more workspace and increased productivity.

Other factors include the placement of heating and air conditioning systems, ductwork, satellite dishes, and large kitchen exhaust fans—elements commonly required in commercial operations.

Cost is another important consideration. It can be very expensive to install a sloped roof on a low-rise building like a shopping mall. The vast footprint of such structures would cause a sloped roof to be significantly taller than the occupied space below, greatly increasing building costs.

Flat roofs also offer more architectural flexibility. Despite the name, flat roofs are not entirely flat—they typically have a slight gradient of 2% to 4%. A flat roof's monolithic design, when properly installed, allows it to hold water without leaking. This makes it ideal for buildings with many roof penetrations or those exposed to heavy snow buildup, where a sloped roof could allow water to enter (watershed design).