What Are Common Disadvantages of Flat Roofing?

How are flat roofs installed?

There are a variety of flat roofing styles for commercial structures in this area, each installed a little differently. The type of business being conducted inside, the owner’s budget and the weather are all factors that determine which type of roofing system is best. The different types of common roofing and their installation process include: 

• BUILT-UP ROOFING 

Abbreviated as BUR, this is one of the oldest types of roofing on commercial structures. And while there are newer types, this one is still being installed all across the country.  A BUR system is installed in a continuous and semi-flexible membrane fabric or felt layers that are alternated with asphalt-based materials like aggregate and bitumen. 

This is an ideal roofing system that is durable, requires minimal upkeep and flat roof repairs are relatively easy. Routine inspections are recommended twice a year to stay on top of small issues and make any flat roof repairs needed to maintain a leak-free roofing system. 

• PVC AND TPO ROOFING

These are thermoplastic single-ply membranes that offer significant benefits, especially in terms of reflectivity with the white surface. They are chemical resistant, ideal for a structure that houses a restaurant or food production operation because it is resistant to fats and oils that escape at the roof. 

PVC (polyvinyl chloride) and TPO (thermoplastic polyolefin) roof materials arrive in rolls that are laid across the flat roof. They are either adhered or mechanically attached to the roof decking. It is a labor-intensive, two-step process installation. These types of flat roof repairs are done using an adhesive and like-material patches.

• EPDM ROOFING

This is another popular flat roofing material, a thermoset single-ply membrane that provides fatigue and scratch resistance. EPDM ( Ethylene propylene diene monomer) is a rubber-type material and has proven to be a durable roofing material over the past 50 years of existence. A highly durable roofing material that can withstand anything thing the weather sends. 

This flat roof repair is done by pressure-applying with a roller of like-material material. It isn’t the best in UV reflection due to the black surface, but a ballast of light color can be included in the installation to make it more energy efficient.

• MODIFIED BITUMEN ROOFING 

Another flat roofing system is also referred to as a rubber roof and is installed in layers of a petroleum-based substance and rubberized material. This gives the roof a strong foot-traffic resistance and is one of the easier roofing materials to install using a self-adhering process.  This flat roof repair is done when the roof surface is completely dry and then a liquid rubber coating is applied.

How much does a flat roof repair cost?

This will depend on the type of roofing material on the roof and the extent of the damage. The cost of flat roof repairs can start around $5,000 and reach upwards of $50,000 or more. By keeping up with routine inspections that catch the small issues will minimize that expense. 

What is the life expectancy of commercial flat roofs? 

Choosing the right type of flat roof material with the longest life expectancy is an important factor for the building’s owner. This isn’t an expense they want to repeat for many years! Lifespans of some flat roofing rubber-like materials between twenty and forty years such as EPDM, PVC, and TPO. Modified BUR and BUR lifespans are between 20 and 30 years.

What are some downsides to flat roofing?

Flat roofing can be an excellent type of roofing for a commercial structure, but some disadvantages include: 

• Drainage issues
• Constant inspections
• Minimal insulation
• Minimal curb appeal
• Prone to Leakage
• Roof buckling
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Why does a flat roof leak in heavy rain?

Flat roofing is not truly ‘flat’, there is a slight slope to these roofs and drainage is crucial in preventing leaks. In heavy rains, because of the low slope, pooling is a common problem, putting the roof at risk of leaking. If the pooling continues, flat roof repairs will start with removing the pooling water, cleaning the drains, and if needed, replacing the damaged areas of the roof.