Leaky air vent on roof
Some of the most nefarious leaks start at subpar installation points. One common subpar installation are air vents on the ceiling. While most air ventsare famous for, or maybe should be infamous for being a primary sources of a roof leak.
Over time seals and flashing can deteriorate, providing an opportunity for water to penetrate your roof. Leaky air vents on the roof lead to installs of more modern air vents; which are less prone to leaks than older versions, but even the best air vents can leak if it isn't installed with care and serviced properly. Air vents often leak because their flashing is damaged, corroded, or improperly installed. Often, those "leaks" are the result of other less obvious problems. One example, water could get through the roofing up-slope of a skylight and then leak out around the skylight's framing.
The first step in any air vents repair is to identify the source of the leak with a thorough inspection. You’ll want to make sure the leak is not just excessive condensation that has moved along the underside of the glass and dripped down the side of the interior. This occurs more often in very cold climates, in single-glazed skylights, and in damp locations like bathrooms, kitchens, and greenhouses.
If your air vents open, check that it is fully closed, and that weather seals are in good condition. In addition, think about whether the leak occurs only in winter, in fall, or when there is snow or ice on the roof.
You’ll also want to look carefully at your roofing, paying particular attention to vent flashing or other roof penetrations. A leak in these locations can travel quite a distance before finding its way to an indoor opening at the air vents. For roof and air vents inspections, hire a contractor skilled in roofing repairs.