The responsibilities you take on when you own your own home include choosing good roofing contractors and overseeing any work that's done on your roof. If you're like many Americans, you aren't very experienced when it comes to roofing, and you depend on your roofing company to take care of everything for you.
However, in order to make informed decisions about your roof's health and catch any obvious problems before they cause too much damage, you should start educating yourself on the basics of how your roof works and what can go wrong with various aspects of it, such as the ventilation and the flashing. Here are a few basics that you need to know about the flashing.
Flashing protects the weakest points on your roof.
The roofing shingles are at their most vulnerable where there's a penetration or a cut edge. That's because while the shingles are designed to shed water, any cut edges are points where water can make its way through the waterproof layer and cause water damage to the underlayment. This is where flashing comes in.
Flashing is a strip (usually made of metal) positioned to deflect water so it won't get through these penetrations. If there were no flashing, leaks would quickly develop in several of these points around your roof, such as at dormer windows, chimneys, satellite dish installations, and roof edges.
Caulk is not a substitute.
Sometimes an amateur or misinformed roof installer will simply seal the gap between a roof edge and a plumbing vent or chimney with caulk. There are several problems with this approach. First, caulk doesn't have a long lifespan to begin with, so even if it worked well for this application, it would need to be replaced frequently. Second, the constant exposure to weather means the caulk starts to crack and pull away from the surfaces it's applied to even more quickly.
When this happens, of course, the watertight seal is broken, and yet the caulk looks about the same as usual so you'd never know without doing a hands-on inspection. Caulk-like product (roof mastic) is required in some instances as a supplement to flashing, but you should never accept it as a substitute.
A typical roof needs several different types of flashing, such as step flashing where a roof slope edge meets a wall as well as drip edge flashing and chimney and vent flashing. Be sure to choose only an experienced roofing contractor, such as Emerald Roofing, who both knows how to work with flashing effectively and is willing to not to cut any corners with your roof flashing.