A neighbor of mine complained recently that he had leaks after a heavy downpour even though a roofing contractor had just upgraded and replaced the roof materials. After investigating, we discovered that the reason was that the metal flashing there before was still the same and hadn’t been replaced.

As it turns out, roof flashing is the secret to preventing leaks, but why?

Roof flashing is the special roofing material used to prevent leaks in areas of the roof either where something is protruding, such as vent pipes or chimneys, or where two sections of the roof system intersect. These areas are especially vulnerable to roof leaks, and flashing materials will help redirect water away from these areas.

Roof flashing may seem like some simple addition to help prevent water from leaking in, but there’s quite a lot more to these roofing materials than meets the eye.

Why is Roof Flashing so Important?

A professional Ellicott City roofer knows all too well that the threat of roof leaks is ever-present. It doesn’t matter what kind of high-quality roofing materials you use or on what kind of roof deck surface you place them. If you don’t also include quality roof flashing materials, then big problems occur. Contractors everywhere are using roof flashing and understand its importance, but many ordinary homeowners remain ignorant.

Just about every roof on every house in America has some protruding element, be it vents, a chimney, pipe boots, skylights, and around dormer windows. All these roofing elements have in common that they are the areas where most roof leaks happen. Even the smallest cracks and imperfections can see water damage occur, and that’s why flashing is so important.

Flashing Materials Prevent Roof Penetration

Even small water leaks in key parts of the roof can generate much more damage to your home’s interior. Painted walls and ceilings will first darken with moisture, and then the paint and plaster will start to bubble, flake, and even fall right off. Those areas around which flashing details are placed will actively guide water away from those vulnerable areas and ensure leaks don’t happen. Your quality asphalt shingles, well-constructed edges, and capable gutters should do the rest.

Whatever material your flashing is made from, it will need your care and attention. If it does get damaged or too worn or is improperly maintained, it might work to channel water into your property and not towards the gutter where it’s supposed to go.

Flashing Works to Prevent Expensive Exterior Damage

Fixing a chimney isn’t a cheap job, and neither is having to replace dormer windows or skylights because of water damage. Installation of a proper protective seal around the edge of these features will protect them just as well as your interior ceilings and walls.

Flashing Adds a Layer of Insulation to a House

One additional important factor is that by creating a seal around a skylight, pipes, vents, a chimney, and other exposed areas, homeowners get an insulating effect as those exposed cracks and gaps are covered up, and thermal movement stops. That makes a building more comfortable and more livable. Contractors understand that roofs can be the source of much difficulty for homeowners, but there’s a lot less to be worried about when proper flashing is installed.

Add Value to a Home

A home that has never had a roof leak likely owes that to the quality of the flashings that are installed upon it. No past leaks means good news to potential buyers and will certainly increase the chances of buyers making offers. Dealing with shingles, gutters, flashings, and related problems is something no buyer wants to think about.

What is the Purpose of Flashing on a House?

The purpose of flashing is to direct water from rain or snow away from vulnerable sections of the roof that are more susceptible to cracks and gaps. Flashing most commonly comes in the form of metal flashing and can be made from various types of metal, such as lead, galvanized steel, or stainless steel. Copper flashing and aluminum flashing are also available. There are several different types that aim to prevent a leaky roof by targeting different roof features.

Sill Flashing

As the name suggests, sill flashing is used mostly around window cavities to prevent leaks. It’s applied around window flanges and sheathing.

Cap flashing

This flashing is used most commonly around a chimney. Base flashing is first applied underneath to seal the gap, and the cap flashing then overlaps with that. It’s also known as counter-flashing or cover flashing.

Step Flashing

This is flashing that is used for roof-to-wall connections. It is installed in layers using rectangular pieces bent in the center to create a right angle to fit between the roof and a connecting vertical wall. The purpose of this flashing is to direct water away from roof-wall connections.

Concealed Flashing

When you can’t see the flashing, it might be concealed within the structure for both aesthetic and practical reasons. One roof feature that typically uses this type is skylights.

Vent Pipe Flashing

Finally, we have the cone-shaped flashing installed right into your roof tiles to cover up pipes and shield them from rain and other precipitation.

These flashings and others are applied slightly differently and may be made from a different material, but they share the same protective function. Besides rain, snow, and other water that might leak in, flashings also prevent debris from getting embedded in those same gaps. Such debris might be blown in by strong winds or even naturally fall off nearby trees, for example.

Can Roof Flashing Leak?

Yes, it can. First of all, no matter if you have a flat or sloped roof, no matter the material your flashing is made from, no matter how professional the installation was, harsh weather like wind, rain, and snow take their toll on your roofing and gutters. To prevent water leaks in the flashing, you’ll need to inspect the roof regularly, especially after periods of extreme weather.

Your home is like any other building, where every horizontal and vertical surface is exposed to the elements. Base flashing can shift, shingles can shift, metal can rust, edges can become uneven, all of which can lead moisture to penetrate the roof and start affecting your attic or other interior spaces. Inspect the roof at least once a year, plus an additional inspection whenever your area experiences unusual patterns of wet weather.

The most common cause of flashing leaks, however, is poor installation. The elements will wear away at your roofing material over time, but mistakes made during installation remain the bigger problem. For instance, a skylight that is measured wrong or sealed incorrectly will create problems sooner or later. A single edge out of place, even by a fraction, can cause the entire roofing dynamic to be negatively impacted.

So, ensure quality installation by using reputable contractors, invest in durable materials that suit the roofing needs of your particular area. The same metal might not work as effectively in the pacific northwest, for instance, as it would somewhere like the Mid-West. For more information or for help with your roof flashing contact Dunsmore Exteriors today.