When a top roofing solution may not be right for you
At Chaffee Roofing we’ve installed and repaired just about every type of commercial roofing system, including PVC roofing. Every property has its unique needs, and sometimes those needs call for an excellent chemical resistant roofing material like PVC (we’re talking about you, restaurants!). However, there are some environmental conditions that are not ideal for PVC roofing, and when possible, you should consider avoiding it for your roofing solution.
Remember, there is no perfect commercial roofing solution or a one-size-fits-all approach. Every building, business, and property manager has their own needs and circumstances that must be considered when selecting a new roofing system.
One of the distinct advantages a PVC membrane roof has over almost all the other low-slope materials is its higher resistance to chemicals like animal fats and grease, which are ever-present on the roofs of restaurants with large grease traps. PVC is also very durable and weather-resistant, which is beneficial in all regions but especially those areas that get a lot of rainfall. And, as we mentioned before, PVC roofing’s white reflective surface makes it an energy-efficient solution as well.
However, there are some disadvantages you should consider when deciding if PVC is right for your building.
So when shouldn’t you use PVC roofing?
PVC Roofing is Expensive and Difficult to Repair
Due to higher raw material costs, PVC is one of the more expensive roofing materials. This is often the first consideration when selecting a material for commercial roof replacements. You’ll want to examine your budget for a new roof and determine if the benefits PVC offers outweigh the higher price point. Other single-ply roofing solutions like TPO and EPDM are more affordable options that provide many of the same core benefits as PVC.
In regards to repairs, PVC is manufactured by several different companies with different proprietary formulations of plasticizers being used to create the unique compounds. Unfortunately sometimes these different blends make it challenging to weld one manufacturer’s PVC membrane to another’s, which can make repairs to PVC membranes a headache. For example, if your selected PVC manufacturer changes their formulations or goes out of business then you may be out of luck in finding a compatible PVC membrane that will weld to your PVC roof. Depending on the extent of your damage, this could result in a costly and unintended roof replacement.
Because of plasticizer migration, PVC is also not compatible with peel-and-stick or self-adhering patching products, like TPO and EPDM are. As a result, there are less options to repair a damaged area of PVC roofing compared to other systems. The rule of thumb with a PVC roof is you can only heat weld a patch repair or new piece of flashing membrane with a compatible formula PVC membrane.
PVC Roofing Can Shatter in Frigid Temperatures
If you live in a climate where it stays cold and icy for long periods of time, like we do in New England, then a PVC roof may run the risk of shattering. PVC is not as flexible of a roofing material like EPDM or TPO which is why plasticizers are added to the PVC roofing formulation to make the membrane pliable and easy to work with. Unfortunately over time this plasticizer migrates out the PVC sheet causing the sheet to become brittle leading to cracks especially in colder climates; this can even lead to shattering when subjected to pressure. Fortunately, the shattering will not spread across the whole roof, but it will open up areas for water to cause roof leaks.
In cold climates such as this, you will most likely only want to consider PVC roofing if your business will directly benefit from its chemical resistance properties. Otherwise, there are more affordable options like TPO and EPDM roofing that provide many of the same benefits.
PVC Roofing Will Shrink Over Long Periods of Time
In addition to shattering, when subjected to icy cold temperatures, PVC roofing can shrink. Therefore, a PVC roof that has avoided shattering still retains an inherent risk. PVC membranes also will eventually begin to pull away from vertical transitions, such as walls, and rooftop units due to shrinking. When it shrinks it will pull at the heat welded seams (which we just covered may have migrated plasticizers in them) and cause the seam to break. This of course is bad news for the roof as it loses its waterproofing properties and typically results in roof leaks.
When PVC gradually shrinks over time, it will require repairs and replacement as needed. With the uncertainty of available compatible formulations down the line, it can be a gamble to invest in a PVC roof in a cold temperature region.
Select What’s Right For You
Hopefully you now have a better understanding of the advantages and disadvantages of PVC roofing, and are not completely discouraged from selecting a PVC membrane roof. It’s good to remember that every roofing system has its pros and cons, and that the right solution strongly depends on the needs of the building and the ones caring for it.
Here at Chaffee Industrial Roofing, we still install many PVC roofs every year, all right here in New England. No matter which roofing solution you select, we’re confident that with the proper installation and the right amount of preventive maintenance and care, your commercial roof system will last for decades to come!
At Chaffee Roofing we are here to help!
Our roofing experts can advise you on the best roofing material for your property.
Have more questions about PVC roofing? Give us a call, we have you covered.
Call us today for all your roofing needs.