Grease And Oil Spills Degrade Roofing Membranes: What You Can Do To Prevent Future Damages

image of exhaust fan that has been damaged by grease and oil

Industrial peanut roasting facility discharge problem.

Everyone knows that the elements can do damage to your roof over time. Things like rain and snow and ice could cause significant problems to roofing systems that aren’t installed properly, or do not have a satisfactory positive drainage system.  However, chemicals and oil discharges through ventilation equipment mounted on the roof cause their own brand of damage to your roofing membrane. Contaminants on the roof can be difficult to spot, so we’ve broken down how to see them, and what you can do to stop grease and oil from compromising your membranes in the future.

How Contaminants Get To The Roof 

The most common cause of roof contaminants that we have found is poor exhaust maintenance. Many kinds of exhaust vents are used in different establishments in order to rid the air of contaminants, but if the exhaust vents and specifically internal filters are not cleaned regularly and properly, it’s possible for some of that discharge to end up on the roof, causing major damage and even creating a fire hazard.

Effects of Oil & Grease

According to T.E.S Engineering, “when fatty acids from cooking fats, oils, and grease come in contact with a roofing system it causes most roofs to soften, delaminate, blister or crack.”

Unprotected membranes can experience degradation around the exhaust vents, and could potentially even cause premature deterioration failing of the roofing system. If that wasn’t reason enough to be concerned, grease on roofing membranes is a fire hazard, and could impact or even void your insurance policy if you don’t have specific coverage for grease damage.

Effects of Other Contaminants 

Excessive bird and raccoon droppings can also cause a degradation of the roofing membranes, according to, “due to the bacteria and acidity in the droppings.” If this is something that is occurring on your rooftop, there are solutions! Regular cleaning can alleviate this kind of problem, as well as protect the bacteria from eating away into your roofing membrane.

Chemical irritants that are coming through ventilation and exhaust equipment can also have a negative affect on your roofing membrane (things like solvents, acids, and oxidizing agents).  There are some chemical discharges we have observed that cause corrosion to metal surfaces both above and below the roof substrate.  This corrosion leads to premature roofing problems so it is crucial to check with your roofing professional to ascertain the steps needed to protect your investment.

How To Spot Roofing Contaminants 

Roofing contaminants can usually be spotted most easily around exhaust vents. If you notice any sort of buildup around the exhaust systems, you should immediately check your ducts to ensure that there are no blockages coming from the inside. Doing routine maintenance inspections of the roof is also a good idea if this sort of debris is found. An expert can assess if the damage is something to be concerned about, or if the leakage is new and still superficial. Notice the ponding of grease at the bottom of the ventilation system in the image below. This will affect the integrity of the roof over time.

picture showcasing oil damage on roofing membrane

How to Repair Contaminant Damage

For Oil And Grease

If contaminants from oil and grease are not severe, it is possible to install a apply specific protective layer  compatible with the existing membrane roof coatings that would mitigate future damage. However, the most important thing you can do to protect your investment is to invest in commercially available traps or filters for oil and grease contaminant control. If the contamination damage is minor, it may not have affected your membrane yet. Talk to your roofing contractor to assess the damage.

Other Contaminants: 

Depending on the chemical contaminant on the roof, and the severity of the damage, your contractor might recommend localized roof membrane repairs to protect your roof from further damage. That being said, this is only an option if the underlying structures of your roof are still sound. If there is underlying damage, a more extensive repair may be in order.

There are certain building uses that give rise to other types of discharges including lint from clothing and fabrics.  This is also an issue with laundry dryer vents that get plugged solid with lint.  The lint discharge can give rise to further problems with roof membranes if it is not cleaned in a timely manner.

How To Stop Future Damage: 

  1. Set up a system of routine roofing maintenance to check on the health of your roofing membrane, and ensure that ventilation and exhaust equipment is working as it should.

2. Establish a positive drainage system.  Positive drainage is crucial for any roofing system, but is even more important when contaminants come into play. We recommend at least ¼ per foot of slope. You can read more about positive drainage and how it works here!

3. Consider localized repairs in areas where your roofing membrane is encountering contaminants.

4. Create an exhaust maintenance schedule to ensure that ventilation and exhaust equipment are working optimally

5. If you’re in need of a repair or replacement, give your roofing contractor a detailed list of the potential contaminants for the roof, which will help to ascertain exactly which materials will work best for your specific needs.

Contaminants on your roof can be a serious problem that affects your membrane over time. If you suspect there is a contaminant issue on your roof, don’t wait; contact a professional to assess the damage. The team at Elite Roofing has over 50 years of experience assessing damage and creating a system that works for the health of your roof and your budget. Contact us here today! Or, if you have questions, chat using the box below during working hours.