How HVAC Units Can Hurt Your Roof

Posted by Heather Johnson in Common Roof Problems,Preventative Maintenance,Roof Inspection Tips

23 October, 2013

HVAC units - North American Roofing

No one wants to stay in a sweltering-hot building — so keeping workers and tenants comfortably cool is high on most facility managers’ lists. Although they make the climate bearable indoors, rooftop air conditioning units are among the biggest culprits when it comes to roof-related problems. Since  rooftop HVAC units penetrate the roof system, the immediate area is obviously at a greater risk for leaking. But additional issues associated with HVAC units — issues that might go undetected during a visual inspection from a maintenance crew member, can also put your roof at risk.

HVAC Condensation

Condensation from HVAC units has to go somewhere, but if it discharges on the roof, it can create localized ponding, which increases the risk of damage. Constant moisture attracts airborne debris, leading to mold, vegetative growth and premature membrane deterioration. It creates unsightly stains and discoloration as well. The solution is to direct HVAC condensation discharge away from the surface of the roof, either through interior discharge lines, when feasible, or by installing condensation lines that direct the discharge to the nearest roof drain.

HVAC Tech Troubles

HVAC service technicians aren’t always trained to look out for the welfare of the roof. Struggling to reach under a low HVAC frame or carelessly tossing tools around can damage a roof membrane. If the tech does not report the incident, it can lead to leaking and saturation damage to underlying insulation. You can reduce the risk by having someone on the roof observing when a technician is servicing the HVAC unit. By installing walkpads around HVAC units, you can also lessen the chance of damage to the membrane in these high-traffic areas.

Adding HVAC Units to an Existing Roof

The ideal time to install HVAC units is during new construction, when the HVAC engineer and the designer can coordinate to ensure that curbs, drainage lines, tubing and electrical access are properly planned for. Adding an HVAC unit to an existing roof is trickier. An improperly installed unit can lead to wind uplift at the separation site and subsequent membrane tears. In regions where the roof is subject to snow loads, adding heavy HVAC units can reduce the roof’s ability to hold as much snow.

Minimizing Rooftop Unit Risk

A roofing professional should be onsite anytime a new HVAC unit is installed to ensure that the unit is secure so it can’t move, and that all curbs, flashings and sealants are correctly installed. Complications around HVAC units can seemingly spring up overnight, but in most cases, a knowledgeable roofing professional can pinpoint potential issues before they become full-blown, expensive, problems. At North American Roofing, we know the special risks posed by HVAC units. We offer one-time inspection and consultation services or, for complete piece of mind, you can enroll your facility in our StarCare Preventative Maintenance plan. When you’re a StarCare member, we’ll carefully inspect your roof twice a year, perform warranty maintenance and make any necessary repairs to keep your facility watertight.

Call us today at 800-551-5602 to find out how a little bit of oversight and prevention can extend your roof’s useful life for years to come.