On Tops Roofing Blog

3 Things You Should Know About Roof Flashing

Written by Jonathan Kennedy | Oct 3, 2022

When it comes time for a roof replacement, it can be overwhelming to hear unfamiliar roofing terms casually tossed around like you’re supposed to know what they mean. What does your contractor mean when they say roof decking? Ever heard of underlayment? And, one of the most important materials, what on earth is roof flashing?

Roof flashing is a material, typically metal, that is used to cover up sensitive areas where your roof meets a penetration, or wall.

As you might expect, it is vital for a high-quality, long-lasting roof. Without it, your home could be left vulnerable to roof leaks, water damage, mold, and premature roof failure. However, most homeowners are unfamiliar with roof flashing and the important purpose it serves.

The team here at On Tops Roofing always walks every homeowner through a thorough explanation of their roof so they know exactly what they’re paying for when they get a replacement. That’s why we’re going to break down three important things you need to know about roof flashing.

By the end of this article, you’ll know:

Let’s get into it.

What is Roof Flashing?

Roof flashing is a thin metal material that lays under the shingles to prevent water from entering any openings, cracks, or vulnerable areas on your roof. It is designed to redirect water away from vulnerable areas on your roof.

While your contractor can install flashing around doors, gutters, windows, flashing must be installed in these specific areas:

  • Sidewalls and front walls (the place where the roof surface meets a wall)
  • Valleys (low points where two roof slopes join)
  • Roof penetrations (vents, chimneys, and skylights)
  • Roof edges (eaves and rakes)

To protect the life of your roof, flashing should be installed in all open roof valleys or anywhere the shingles butt up against a wall or chimney. As long as it’s properly installed, flashing will help these areas stay dry and leak-free.

3 Important Things to Know About Roof Flashing

1. Flashing Might Not Need to be Replaced

Just because you’re getting your roof replaced doesn’t necessarily mean you’ll also need to replace your flashing.

When they come out to give you a quote for your roof replacement, your roofing contractor will inspect your flashing to make sure it isn’t rusted and that the integrity of the metal is strong enough to keep your home safe from the elements. Here are some other flashing issues your roofer will look for:

  • Missing caulk around the flashing edge: The caulk around the edge of the flashing will degrade over time, which can cause it to crack or peel.



  • Damaged flashing: Your inspector will make sure that the screws and nails attached to the flashing haven’t become loose and raised. They’ll also look for cracks and warped metal.



  • Missing flashing: Wind storms can cause flashing to be torn off completely, so your roof inspector will make sure that your flashing is intact and installed where it needs to be.

Your flashing won’t need to be replaced if the metal is still intact and your contractor doesn’t spot any issues during their roof inspection. However, if your flashing is damaged, rusted, or if you’re upgrading from 3-tab to architectural asphalt shingles, it will need to be replaced.

2. Roof Flashing Needs Annual Maintenance

No matter what kind of metal it’s made of, your flashing should outlive your shingles and other roofing materials. However, flashing needs to be inspected as part of your roof maintenance routine to make sure it stays in good condition:

  • Make Sure Flashing Isn’t Loose - It’s common for roof flashing to loosen over time. This can happen in one of two ways: the screws anchoring the flashing become loose and pull out, or the metal wears away around the hole where the flashing was originally installed. Your contractor can solve this issue by screwing the flashing into the roof decking underneath to lock it in place. They’ll then cover each screw head with roofing cement to keep water from leaking into your home.

  • Fill Holes - Although flashing is weather-resistant, it can corrode if consistently exposed to harsh conditions. This doesn’t mean you have to completely replace your flashing; you’ll just need a contractor to patch the hole. They’ll cut a piece of flashing that’s larger than the hole itself, place it over top, and then secure it using roof cement.

By investing in annual roof inspections, you can avoid costly roof repairs and catch small flashing issues before they become bigger problems. Flashing is just one of the elements your contractor will check during their inspection. You can read this article to learn more about the other components included in a professional roof inspection.

3. The Importance of Roof Flashing

A roof leak is one of the most common, and potentially severe, challenges you could face as a homeowner. Leaks don't just damage your roof; they can also wreak havoc on your attic walls, ceiling, and the interior of your home. Because flashing is specifically designed to prevent roof leaks, it also helps protect the overall structure of your home by increasing your roof's lifespan, preventing the growth of mold, and protecting your home's insulation.

  • Flashing Increases Your Roof’s Lifespan - When your roof leaks, moisture gets trapped in the roof’s structure. This includes your roof’s wooden sheathing, underlayment, trusses, and rafters. When these elements take on water damage, they can rot and lead to premature roof failure.

  • Flashing Prevents the Growth of Mold -  When water infiltrates an attic, it creates a damp atmosphere that encourages the growth of mold. This can impact the air quality in the rest of your home, potentially creating an unhealthy environment for you and your family.

  • Flashing Protects Your Home’s Insulation - A roof leak could also damage the insulation in your attic, which puts your roof’s health at risk. For example, homeowners who live in colder climates are prone to ice dam formation if their attic insulation is damaged. This can cause shingle deterioration, decking decay, and more.

Need Help Maintaining Your Flashing?

Now that you know what roof flashing is and how it works to keep your home safe from roof leaks, you’re probably wondering how you can make sure your flashing stays in good condition for years to come. Well, let us re-emphasize the importance of roof maintenance!

You might assume your roof only needs attention when it’s damaged or leaking. The reality is that proper maintenance may help prevent that damage. It’s as simple as doing some of your own roof upkeep and having regular professional maintenance.

It’s best to hire a local contractor to help you with your maintenance routine because they’re familiar with roofing problems in your area and the specific weather patterns of your region. They’re also more likely to get to your home in a timely manner if you have a roofing emergency. You can learn more about the benefits of working with a local contractor here.

If you live in Raleigh and need help maintaining your roof, consider us! With over 30 years of experience, we know how to give homeowners, like you, the high-quality roofing experience they’ve been looking for. If you want a free roof inspection, estimate, or to ask us questions about your roof flashing, fill out the form below. We’re be happy to help!