5 Commercial Flat Roofing Systems For Your Business (2024 Update)

May 25th, 2021 BY First American Roofing

Commercial buildings need adequate roofing systems to ensure efficiency and to provide a leak-free roof, just like on your home! Unlike your home, commercial buildings generally use some sort of flat roofing system. There is more than just one type of flat roof to choose from, with each providing plenty of benefits, but also its fair share of downfalls. We’re going to go over a few of the most common types of commercial flat roofing systems that can help provide your business with a secure roof that meets your needs.

What is a Flat Roof?

A flat roof is actually a low-slope roof most commonly used for commercial buildings like apartment buildings, warehouses, big box stores, etc. They look flat, and you can walk on them like they’re flat, but they’re really at a 1/2 inch or 1/4 inch slope to ensure water can runoff.

There are many different types of flat roofs ranging from simple and cost-effective to more premium and high-end flat roofs. The three main types being; membrane, built-up roofing (BUR), and modified bitumen (MBR). Because snow and rainwater may sit for longer periods of time on these low-slope roofs, flat roofs must be made out of very watertight materials to prevent leaks and sagging.

commercial flat roof

Commercial Flat Roofing Systems

There are quite a few types of flat roofing systems that can benefit your business and commercial building. We’ll weigh the pros and cons to help you determine which might be the best fit for cost, longevity, and waterproofing.

Membrane or Single-Ply

Single-ply roofing is often the preferred type of roofing material used by building owners and builders because of its resistance to weathering and peeling. They’re called single-ply because they are designed to be just one layer of material. But that one layer is robust enough to ensure a flexible, watertight seal for most size low-slope roofs.

There are two main categories of single-ply membranes: thermoset and thermoplastic. Thermosets are made of synthetic rubber polymers, while thermoplastics are manufactured with plastic-based materials that are reinforced with fiberglass or polymer. Both are highly flexible and strong and provide UV resistance.

There are then 3 main types of single-ply roofing used by the majority of commercial roofers today. They are TPO (thermoplastic polyolefin), PVC (polyvinyl chloride), and EPDM (ethylene propylene diene monomer). TPO and PVC are thermoplastic single-ply membranes. EPDM is a thermoset and is manufactured in an extra-large size that allows for fewer seams, which means fewer places are susceptible to leaks, and it looks much sleeker.

Build-Up Roofing (BUR)

Built-up roofing is one of the oldest forms of materials used for flat roofs, having been used for almost 100+ years. It consists of building up multiple layers to create an impenetrable, seamless roof that is highly durable against damage. The first, or bottom, layer is an insulation board made of a strong core foam and reinforced with fiberglass. Then alternating layers of tar and/or asphalt go on top of the insulation or cover boards. And lastly, a layer of roof felt topped off with gravel to seal all of the layers. This seamless composition makes for a highly durable and low-maintenance protection for any low-slope commercial roof.

Modified Bitumen

Modified bitumen is a combination blend of asphalt and chemical polymer which can be applied using several techniques at different points of the year, making it an optimal choice for many new builds. Modified bitumen can be applied using adhesive sheet rolls, hot melted or mopped asphalt, a torch, or cold-applied asphalt. This type of material is highly rated against storms, wind, fire, and hail. And because the seams are melted together using heat, it creates a seamless air and water-tight seal.

Liquid Applied

Liquid applied roofing literally comes in a liquid form and is either sprayed or rolled on. This roofing technique makes for a really easy application. And because it is so malleable, it’s able to seep into hard-to-reach corners and crevasses, creating one of the best seals against water leaks out of all the low-slope roofing types. It also emits very little odor and doesn’t require hot torches or other complicated methods of installation. This makes Liquid Applied roofs ideal for businesses looking to quickly re-surface the roof without having to close the building.

Green Roofs

Green roofs, or vegetative roofs, are not meant for every building but can be the perfect option for a company looking to be more sustainable and find more natural ways to insulate and protect their roof. A green roof includes planting vegetation and making a green space on the roof that improves water absorption, avoids the need for hefty drainage systems, and can make for the perfect living space for local wildlife like birds and bugs. Green roofs can also be transformed into a green space for employees to enjoy as long as there is safe access to the roof. Green roofs also improve oxygen levels and reduce the urban heat island effect that you see in highly metropolitan areas with tons of concrete and very little plant life.

These are some of the most commonly used roofing materials for commercial flat roofs and come highly recommended for those looking for an easy-to-install, seamless roof option for their business. Many of these roofs can be installed quite quickly, and even if they don’t last for many years (due to their expected lifespan), they can be repaired quickly and easily as well. For these and other roofing services you can count on, contact First American Roofing today.