Your rooftop air conditioner offers a lot of benefits. Compared to ground units, rooftop units accumulate less dirt and yard debris, so you don’t have to clean your cooling system as often. Additionally, rooftop air
conditioners sit just out of earshot, so you don’t have to listen to the rumble and buzz whenever it turns on.
However, your roof might not like the air conditioner as much as you do. In fact, air conditioning units remain one of the biggest culprits for roof-related problems and damage. If you don’t take care, your roof-mounted air conditioner could lead to the following problems.
1. HVAC Condensation Leads to Stains
Air conditioners, by their very design, generate some levels of condensation. As refrigerant circulates through the system, moisture in the air condenses on the coils. Ideally, this excess moisture drips into a
condensate pan, and the water directs to a drain line.
But dirt and mold can block the drain line while aging condensate pans may develop cracks. As a result, the condensation will pool around your unit rather than drain safely from your roof. When the water
evaporates, hard minerals such as calcium and magnesium will linger on your shingles, resulting in white stains.
2. Refrigerant Leaks Contribute to Mold Growth
Refrigerant acts as your air conditioner’s blood. As it pumps through the system, refrigerant enables your air conditioner to effectively regulate its own internal temperatures (and subsequently your home’s
temperatures as well).
But when leaks develop, refrigerant escapes. Without adequate refrigerant, the evaporator coils become too cold. Any moisture on the refrigerant line will freeze, resulting in ice buildup.
As the ice melts, the water will drip and pool around your unit, creating a comfortable environment for mold and algae to grow. Not only will the mold stain and discolor your roof, but it will also rot your
roofing materials, compromising their integrity.
3. Poor Installation Results in Water Damage
Any feature or object that penetrates your roof puts your home at risks for leaks. Chimneys, skylights, vents, and air conditioners require careful installation and maintenance to reduce that risk.
Chimneys, for example, need protective flashing along the edges of the stack to prevent water from entering the home. Skylight frames need precise measurements to keep runoff and condensation at bay. Your air conditioner, too, needs a proper mount to remain level, and it needs flashing to seal gaps between your shingles and your unit.
But if your original technician took shortcuts, your air conditioner may tilt at an awkward angle. This tilt causes the condensation and water to drip directly onto your roof rather than into the drip pan and
drain line. And if your unit lacks adequate flashing, you can bet that the resulting drips and water will find their way into your home.
4. Careless Technicians Damage Roofing Materials
To avoid leaks and water damage, you may regularly hire HVAC technicians to inspect your air conditioner. But though most technicians can pinpoint leaking evaporator coils or replace fins, fans, and motors with
ease, not every technician has the training to safely mount and work on a roof.
During hot weather, shingles become soft, making them vulnerable to brushing, bumping, scuffing, and scraping. If a technician doesn’t take care when walking on your roof, he or she may loosen the protective
granules from your shingles or pull the shingle away from its nails entirely.
Furthermore, if a technician were to carelessly toss tools or struggle to adjust a heavy mount or frame, he or she could damage the water membrane underneath the shingles. The damage could lead to leaking and saturation damage to underlying insulation.
Talk a Roofer About Repairing the Damage
While you don’t have to remove your air conditioner completely, you should take care to ensure your unit doesn’t damage your roof. Hire a professional roofing contractor to inspect your roof for stains, leaks, and