Residential VS Commercial Roofing: What You Need To Know

Roofs are used to cover the top of a building or structure. But, just because house roofs do the same thing as commercial building roofs doesn't mean they're the same.

In this blog, we're exploring the difference between commercial and residential roofing, including:

• Common materials for each
• Pitches on commercial vs residential roofs
• Roof maintenance
• Commercial vs residential roofers

What is commercial roofing? 

Commercial roofs are roofs on retail buildings, businesses, factories, warehouses, and other commercial buildings. Typically these roofs are large and flat.

Flat roofs typically usually need more upkeep and repairs. The flat surface is better to handle the weight of machinery on the roof, like smokestacks or large HVAC systems. We also need to consider the need to cover a large area. 

What is a residential roof?

Residential roofing applies to structures meant for people to live in. Think about residences or homes.

Residential homes have less to worry about in terms of design and are easier to maintain, repair, and replace. They usually have higher pitches, vents, eves, more flashing, and use shingles.

Construction of residential vs commercial roofs

The building composition of a residential roof is different from a commercial one. Commercial roofs require way more water protection and weight management because they're flat, and often hold very large, heavy pieces of equipment.

Residential roofs are constructed by attaching plywood to timber rafters, forming the roof deck. Then, roofers install a protective underlayment before laying down shingles, shakes, or tile.

A commercial roof comprises several layers: insulation, decking, protective, and reflective coating. The precise layering depends on the type of roofing used.Flat or low-pitched commercial roofs are not ideal alternatives for ordinary residential roofing materials.

Commercial roofing materials have far more alternatives than residential roofing materials. Modified bitumen, tar and gravel, single-ply coatings (PVC, TPO, EPDM), sprayed polyurethane foam, or other commercial roofing systems are common.

Commercial vs residential roofing materials

The materials used on residential and commercial roofs differ depending on the design, pricing, and weather conditions. You need to know what material you’d use on a particular roof. We'll explore the main differences in roofing materials later on.

Commercial asphalt roofs VS residential

When you think of an asphalt roof, you probably think of shingles. That's because asphalt shingles are typically residential roofs.

But commercial roofs can have asphalt on them, too. The difference is that the asphalt isn't in shingle form. Roofers use multiple layers of asphalt on low slope commercial roofs to provide a weather-proof and protective surface.

There are two categories of asphalt commercial roofs: Built-up roofing (BUR) and modified bitumen systems (MBS)

Built-up roofing (BUR) is when the roof is layered with vapor retardant, insulation, asphalt membrane, and surfacing material. These roofs are put together on the job.

Modified bitumen systems (MBS) are factory made. It's installed in a single ply sheet, but can be layered depending on the roof and structure needs.

Metal residential roofs: Also an option for commercial?

Metal roofs require some slope in order to move water, unlike gravel or other flat roof systems. But, that doesn't mean that commercial buildings can't have metal roofs.

Smaller commercial structures like shops, individual stores, or medium-sized warehouses may have metal roofs. The roof would need to have a slope, though. This means that any large HVAC systems or air vents could not be placed on the roof.

Commercial buildings may have a mix of flat and metal roofs, too. Metal overhangs or sections of the roof may be used closer to the edges, while the large top could be a flat roof system.

There are plenty of benefits for pitched metal roofs on commercial buildings:

• Adds height to the building.
• Plenty of metal options to choose from
• Energy efficient with insulation and soundproofing
• Pitched roofs are better for evaporation and humidity management

Typical roof slope of a commercial building

The slope of a commercial roof is typically very low or fully flat. This is because most commercial buildings are very large. If they had a pitched roof, it would have to be quite tall in order to maintain that pitch across the building.

Commercial roofs are also often flat because they need to support heavy equipment like large HVAC blowers and industrial pipelines. More aesthetic flat commercial roofs use blower outlets, smokestacks, and skylights to break up the surface.

Very low slope or flat commercial roofs are commonly found on:

• Warehouses
• Shops
• Restaurants
• Malls
• Strip malls

Even though apartments are residential buildings,they usually have a flat roof, too, for all the reasons listed above.

Roof slope of a residential house roof

Sloped roofs are required for residential homes in order to move show, hail, rain, water, and debris. It also makes space for an attic in the home, which is super important for air flow and ventilation.

A residential roof's pitch will be steeper compared to a commercial roof. With the uncommon exception of solar panels, residential roofs don't need to support any accessories. Residential skylights are built to fit the slope design of a house roof.

Roof maintenance on commercial roofing vs residential

While both residential and business roofs require upkeep, the methods used to do so differ. Residential roofs require less care because they have lesser square footage. As a result, a homeowner is unlikely to plan regular maintenance or inspections of their residential roof, especially if there are no signs of leaks or other concerns.

On the other hand, commercial roofs necessitate routine maintenance to avoid leaks and further damage caused by weather events, heavy foot traffic, or aging. To correctly evaluate the condition of the roof, the inspection process necessitates the assistance of a skilled roofing contractor.

Differences in roof installation and repair

Commercial and residential roofs have very different installation processes. That's because the materials used on them are so different. Commercial roofs are also way larger.

Commercial roof repairs can become a costly undertaking. When water penetrates the strata of a commercial roof, experts must evaluate the entire structure. Repairing a small part of the roof may be simple. Adding new layers to a large section of the roof could be more challenging. It all depends on the extent of the repairs needed.

Fixing a small part of the roof may not require as much time or effort. However, repairing a large section of the roof may be a more complex and time-consuming task. A minor leak can quickly add up in cost.

Leaks on a residential roof can occur in isolated areas where shingles or flashing has gone loose. The work is typically completed in a few hours. Of course, leaks might signify severe issues with a residential roof. However, localized leaks caused by minor faults are more common.

Commercial vs residential roofers

Commercial roof installers will have a different set of skills than a residential roofer.

Commercial roofers are:

• More specialized in flat roofing
• Have a unique skill set working around large roof accessories like chimneys, smokestacks, HVAC systems, etc.
• Knowledgeable in TPO roofing and other commercial roof systems
• Used to longer projects

Residential roofers are:

• Specialized in shingles, most likely
• Know how to work on slopes
• Used to shorter jobs
• Have a more general skill set

Both residential and commercial roofers will be skilled in their trade. When property owners are looking for a contractor, it will boil down to finding a professional that has the necessary experience to accomplish their residential or commercial roofing project.

Software to work smarter

Both commercial and residential roofers can benefit from roofing software.

The software you use to quote your jobs matters. Roofr's satellite measurements and digital proposals work great with residential and commercial roofers alike. Explore our tools and try our CRM for free today! Or, book a demo with our team to learn more.

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