Sheet Metal: An Essential Element of the Industrial Roofing Process

Shoppers Drug Mart industrial roof with custom sheet metal from Elite Roofing.

In this article we explore how key sheet metal components—copings, drip edges, and counterflashing, and more—all add to the performance and longevity of your industrial roof.

Many building owners are only partly aware of the pivotal role that sheet metal components play in the longevity, performance, and design of industrial commercial roofing systems. Installed along parapet walls, roof upturns, expansion joints and projections, sheet metal components protect the building interior, equipment, inventory, and other assets. Visual appeal is another benefit, with metals of various finishes, styles, and colors adding aesthetic value.

Industrial roofers and building owners rely on sheet metal components for roofing systems

One proof point that sheet metal is so critical to roofing structures is that the Ontario Industrial Roofing Contractors Association (OIRCA) requires that all members have an in-house sheet metal fabrication shop. Sheet metal components for industrial roofing can be pre-painted steel, aluminum, copper, zinc alloys, or other materials. Pre-painted steel is the most common given its strength, durability, and affordability. The metal is typically pre-painted, with typical thicknesses ranging from 20 gauge to 24 gauge for steel (from 0.018 to 0.028 inches thick).

What sheet metal components do industrial roofs have?

The most critical sheet metal components for industrial roofing jobs include copings on top of parapet walls, drips edges, counterflashings, snow guards, roof railings, and metal cladding. You’ll find each described below.

Custom sheet metal in the fabrication process.

Metal coping on parapet walls 

The role of parapet walls

Parapets—vertical wall extensions project above a flat roof—serve many purposes:

  • They conceal rooftop equipment;
  • help prevent falls for rooftop workers;
  • prevent dirt and debris from collecting on the roof;
  • help prevent wind uplift;
  • reduce foundation erosion caused by uncontrolled water flow;
  • and more. 

It’s concerning that such a vital building element is one of the most vulnerable points for water to infiltrate. That’s where metal coping and drip edge come into play.

The role of parapet wall copings

A parapet wall that has been infiltrated by water can be the source of mould, mildew, dampness, rot, and other problems that lead to costly repairs. Metal copings protect the top of the parapet wall from water damage, weathering, ultraviolet light, and general exposure to the exterior environment. In frigid weather, copings also keep water from entering the wall assembly and freezing. This can cause cracks, mortar joint failure, and general deterioration of the wall’s structural integrity. Metal copings also protect steel lintels, window sills and door openings from water damage.

Metal copings are usually fabricated from 24-26 gauge pre-painted steel to ensure they are corrosion-resistant, waterproof, and fire-proof. 

Drip edges on the sides of wall copings

Parapet wall copings have two separate drip edges, one on the wall’s exterior and one on the roof side. These drip edges divert water from the roof’s edge or fascia into a gutter or onto the ground below. This controls water flow and ensuring proper water run-off. Often made of steel or aluminum, drip edges must be corrosion-resistant. 

Counterflashing at seams and vertical upturns

Leaks and water infiltration can occur at joints or seam points where a crease occurs or where vertical protrusions meet the roof’s surface. For example, it can occur around HVAC equipment, skylights, chimneys, and similar building elements. Flashing consists of several layers, with counterflashing—usually a continuous strip of metal–installed as the top layer. Also called a cover or cap flashing, counterflashing is commonly made from pre-painted steel. Counterflashings are also used to secure membrane upturns from falling down.

Snow guards 

Metal snow guards distribute the snow load evenly across a roof. This helps snow and ice melt completely and drift off the roof in small amounts. Used on sloped metal roofs, snow guards reduce the risks of ice dams and large chunks of snow and ice sliding off. Without them on the roof, it can potentially endanger people and property below. 

Roof railing systems

Sheet metal is used in roof railing systems that are required for the safety of rooftop workers. According to regulations set by Canada’s Infrastructure, Health, and Safety Act (IHSA), a barrier of at least two meters from the perimeter of the roof must be present when a built-up roof is being constructed. Barriers must also be installed around skylights and other openings. Sheet metal can be an integral part of these fall prevention barriers.industrial roof with sheet metal flashing.

Metal cladding along parapet and knee walls

Sheet metal cladding, while not specifically a roofing component, is a popular material for industrial architecture. Cladding is a protective covering that is bonded to the substrate of building exteriors, backsides of high parapet walls, and knee walls. Metal cladding is particularly effective for roofing projects because of its durability, resistance to the elements, and ease of insulation for covering large surfaces. Several different types of metal can be used, including pre-painted steel, aluminum, copper and zinc. 

Expertise in sheet metal fabrication and installation matters 

Accurate measurement, precise fabrication, and expert installation of these components are critical to the optimal performance of your industrial roof. Don’t settle for less than a roofing partner who can deliver high-quality components that are compatible with all your roof hardware and equipment. Also, remember that sheet metal roof components are only as good as the accuracy of the installation. 

Protect your facility by hiring Elite Roofing, Toronto’s expert in the fabrication and safe installation of made-to-measure sheet metal components and cladding. We are known throughout the Greater Toronto Area for our superior integrity, craftsmanship, and long-lasting results. Contact us the experts at Elite Roofing for your next roofing project.