The roof of a house is the first line of defense against water intrusion. The roofing system should be checked by a contractor at the first sign of water in your home. The roofing system is working properly, so why is water appearing on the walls or ceiling? You can check a few things before calling in a construction professional to dig a little deeper.
It’s best to let your ceiling systems, including your ventilation systems, be checked by a professional. Exhaust from your furnace and water heater carries a lot of moisture that can cause problems when not ventilated properly. Your oven should be checked by an HVAC professional annually. Let them know immediately of any ventilation problems.
This article focuses on checking roof mounted black box exhaust vents in cold weather. Look online or at your local home improvement store for a roof vent cap. You will see how the exhaust air is pointing down the ceiling. These roof caps are typically used in kitchen and bathroom exhaust air ventilation systems.
On a quiet frosty morning or after a light snowfall, check the roof vent extractors by turning them on for a few minutes and head outside to find a melted patch on the roof in the discharge path under the vent cap. This will not tell you that it is working 100% but it will tell you that it is not. Check the intake grille for lint or clean the cooker hood filter and recheck the ceiling. If there are no signs of hot exhaust with the fans running, something is wrong. Time to call in a contractor to check the system. You will have to go to the attic and check if it is clogged, disconnected or ventilated without insulation. Your contractor should also go up on the roof to verify that the exhaust vent caps are working properly.
The attic temperature in an average new home is designed to follow the outside temperature. Venting hot, humid air into an icy pipe will cause moisture to condense in the exhaust vent of a bathroom or kitchen on a cold winter day. This will drain back into your home and depending on how the exhaust is running, it may not show up right away. Any plugged or disconnected exhaust vent pipes can discharge hot air into the attic. Any moisture in the exhaust vent air can freeze in the attic and cause what appears to be a water leak when the attic temperature rises above freezing.