There are many different reasons why roofs can leak. But we have found these to be the 3 most common sources of leaks from roofs:
1. Deteriorated Pipe Boots
Pipe boots are the plastic boots with a rubber collar that surrounds the plumbing vents that extend through the roof. Over time, the UV rays from the sun will deteriorate the rubber collar creating an entry point for water. Most of the time, these leaks will go unnoticed for weeks and even months before they start to show up on your ceiling. These leaks tend to be smaller and are noticed on ceilings near bathrooms or kitchens. Typically if you have one leaking, the others are more than likely to the point of needing replacement as well. Depending on how old the roofing system is, there are a few options. If the boot is still in good condition and the cause of the leak is the deteriorated rubber, then a new UV collar can be slipped over the pipe and on top of the boot. If the plastic boot itself is damaged, then the entire boot should be replaced. It is recommended to go ahead and replace all of them at the same time to prevent leaking should another boot be deteriorated as well. It's kinda like the tires on your car.
2. Brick Chimney's
We have found, sometimes after chasing a leak that was thought to be the flashing around the chimney, that brick chimney's can leak from water absorption through the brick and mortar. Typically this happens during very heavy rains and after multiple days of heavy rains. High winds also play a big part in leaks on brick chimney's as the water is forced in through the porous surface. If this is found to be the case, a masonry sealant may be the answer to solving the leak.
3. Clogged Gutters
This is really not a roof issue but more of a gutter issue. During the fall is when most of these types of leaks occur when heavy amount of leaves and debris fall from trees and get trapped in the gutters. Water will back up and can drain behind the gutter and into the soffit and fascia on the eave. This type of leak will show up on ceiling to wall transitions and tend to be pretty significant. A good practice is to have the gutters cleaned out several times over the fall season or install a high quality gutter cover to prevent gutters from being clogged.
HOW TO PREVENT LEAKS
Not all leaks can be prevented as high winds and strong storms can blow water in areas that the roof just cannot handle. Most of the time, an inspection can catch most of the maintenance items that can cause leaks to prevent them from ever happening. It is recommended to have your roof inspected once a year for preventive maintenance.