Commercial Roofing

Types of Commercial Roof

The 5 systems are:

• Built-Up Roof (BUR) also known as the “Hot Tar and Gravel” roofs
• Metal Roof
• Modified Bitumen Roof
• Single-Ply Membranes as in TPO, PVC, and EPDM
• Spray polyurethane foam-based roof systems.

Built-Up Roof (BUR)

A built up roofing system is a roof where multiple layers of asphalt or tar are alternated with ply sheets. This layer is then applied over the reinforcing fabric, which can be various different materials, such as organic or fiberglass mats. Often times, this layer is applied over insulation that is already attached to the roof decking. However, insulation, while generally recommended, is not a mandatory component in a built up roofing system. Built up roofing systems are typically used on low-slope or “flat” roofs.

There are a few benefits of utilizing a built up roofing system.

Protection:  Built up roofs typically provide impressive waterproofing and ultraviolet protection. Because of the multiple layers of bitumen and saturated felts, among other potential material combinations, a built up roofing system creates a barrier that guarantees protection against the elements for many years.

Energy efficient: With a built up roofing system, you are able to save energy by utilizing your property’s heating and cooling systems less often. Built up roofs usually include special coatings that reflect ultraviolet rays, which help maintain a consistent building temperature. This means that when you use a built up roofing system, your interiors will stay warm or cold for longer periods of time. This can result in lesser energy bills. 

Durability: A built up roofing system is fire-resistant and is able to withstand strong winds. The durability of this roofing system will give property owners peace of mind, knowing that their investment won’t get damaged regardless of how harsh the weather outside is. 

Low-maintenance: Unlike other roofing materials and types, a built up roofing system is very easy to maintain. This kind of roof has fewer individual parts that need to be repaired or fixed, and is likely to get damaged over time. 

Fire-resistant: Because of its aggregate top layer, built up roofing systems are also known to be fire-resistant. Using this type of roof will lessen your property’s susceptibility to start and spread fire. 

Modified Bitumen Roof

Flat roofs are most often used in commercial and industrials buildings. They are gaining in popularity for residential applications too. And, in all cases, a modified bitumen flat roof offers many advantages. A modern take on the old built-up roofing (BUR) system, modified bitumen flat roofing is a single ply system made of asphalt bitumen, modified with polymers and reinforced with fiberglass and/or polyester. It’s this combination of materials that gives modified bitumen (mod-bit) flat roofing advantages that few other roofing systems can match.

Here are some of the advantages to a Bitumen Flat Roof:

Extremely Puncture and Tear Resistant: The advantage here might not be mod-bit’s strength against damage, but the peace of mind it offers. The fiberglass and polyester layers can handle anything the roof faces, from foot traffic to wind-borne storm damage.

Durability: Yet another “peace of mind’ advantage is the fact that you won’t have to worry about replacing a mod-bit flat roof for a very long time. The same strength that gives its indestructibility gives it a lifespan to match.

Pliability: Flat roofs are notorious for gaps forming in the seams and between the roofing and flashing. Mod-bit roofs expand and contract according to temperature without losing their shape or adhesion.

Eco-Friendly: Mod-bit roofs can be installed to offer high solar reflectivity and thermal emission. That reduces your energy usage and heating and air conditioning costs. And it’s much better for the environment.

Single-ply Membrane: Single-Ply membranes, usually referred to as TPO and PVC, are wide sheets of factory-made synthetic rubber or vinyl type of materials. These membranes are usually very thin and come in rolls from eight feet wide to twenty feet wide.

These membranes do not come with any protective surfacing. The composition of the top layer is such that it can withstand ultraviolet light rays for only a certain period of time.

An adhesive is used to adhere the membrane to the properly cleaned substrate. If the substrate is not properly prepared; removal of dust and particles,  according to manufacturer’s instructions, the adherence is compromised and the life of the roof is reduced.

The PVC and TPO membranes are seamed by heat welding with hot air, with the use of solvents, as a primer.

EPDM is made from 2 compounds that are derived from oil and natural gas. The inner tube of a tire is the same material as EPDM. The seams are sealed with liquid adhesives or nowadays a special self-adhering tape is also used. Over a short span of time, EPDM has become plagued with problems. The major one deals with the adhesive’s inability to withstand the extreme heat conditions on a roof. Also, the single-ply membrane is prone to punctures and degradation to ultraviolet light.