Your rooftop mechanical equipment may be adversely affecting the long-term performance of your roofing system by discharging condensate water onto the roof surface and creating localized ponding. Ponding water negatively affects a roof system''s performance through deterioration, debris accumulation and vegetation growth. In addition, a continuous flow of water over the roofing material may cause erosion, stains and discoloration of your roof. To avoid these situations, maintain proper HVAC maintenance, use drainage lines that discharge somewhere other than the roof surface and have your roof inspected twice a year.