Your roof protects your home from rain, snow, and wind, but it’s important that water doesn’t penetrate the parts of your roof where two different materials or surfaces meet. That’s where roof flashing comes in.
Roof flashing is one of the most important elements in a properly installed roofing system. Though rarely noticed on a first inspection, roof flashing prevents leaks, protects the structure of your home, and prolongs the life of your roof.
Having an understanding of what flashing is and where it may be located can help you avoid costly water damage.
What Is Roof Flashing?
Roof flashing is a weatherproofing material designed to go over the joints in a roof. It helps drain water away from the roof joints and directs it to the roofing sheets underneath the shingles.
It is commonly made of galvanized steel or aluminum, but copper and zinc are occasionally used. Flashing can also be made using synthetic rubber, butyl rubber, and acrylic, among others.
Although the roofing shingles protect the large portion of your roof, they offer minimal protection to the joints. The flashing materials are, therefore, installed along the edges of the roof joints. The materials are cut into appropriate shapes and sizes and then nailed or stapled to the roof sheathing below the shingles. However, some methods may vary depending on the type of joint the flashing will cover.
In addition to protecting the roof joints, flashing protects the home’s interior from water damage. If not installed properly, water will leak through the roof joints and damage the shingles, rot the roof wood, promote mold growth, and ruin the home’s interior.
Where Is Roof Flashing Installed?
You should install roof flashing anywhere on a roof where it meets another surface or an opening that allows water to enter. There are several types of flashing depending on the location to direct water away from vulnerable spots and prevent leaks.
The most common places include:
- Chimneys. Flashing seals the junction where the chimney meets the roof. Step flashing runs up the sides of the chimney, and counter flashing overlaps this flashing to prevent water from getting underneath and causing leaks.
- Roof Vents and Pipes. Pipes that penetrate the roof need a special type of flashing to seal the opening. These special covers are called pipe boots and generally have a flexible collar that fits around the top of a vent or pipe to keep water out.
- Roof Valleys: Valleys are the areas where two sloping sections of the roof meet. Since valleys tend to collect large volumes of rainwater and melted snow from the roof, they usually have metal flashing installed along them or special underlayment and shingle installation.
- Skylights. Skylights also require flashing around their perimeter to direct water off of their frame into the shingles below.
- Walls and Dormers. You install step flashing at the intersection of a roof and a wall (such as a dormer) using overlapping metal pieces. The flashing directs water down the roof instead of allowing it to penetrate the wood.
- Roof Edges. You install drip edge flashing along the edges of a roof, directing water away from the roof decking and helping to prevent water damage and wood rot.
All these flashing types help protect a home from water damage. This is especially true in New England, where homes are subject to severe weather with heavy rains, snows, ice, and changing temperatures.
Why Flashing Is Important for New England Homes
Massachusetts homeowners know a thing or two about the weather. Your roofing system must be able to prevent moisture from getting in all year, whether it is spring rains or winter snow storms.
Proper flashing helps prevent:
- Roof leaks. Flashing diverts water away from joints, seams, and openings in your roof to protect those areas from water penetration.
- Roof structure damage. Flashing stops water from getting to your roof decking, framing, and other structures, protecting them from water damage.
- Mold and rot. Water entry can result in unsightly and even harmful mold and damage to your ceiling, walls, and attic.
- Severe winter weather damage. Your roofing system’s first line of defense against harsh winter weather is underlayment, flashing, and ice-and-water protection membranes, all installed appropriately.
- Premature roof aging. Flashing helps prevent your roof from premature aging by keeping the water out of your roofing system. This helps save thousands of dollars in roofing repairs and replacement.
No matter how good your asphalt roofing shingles are, bad or badly maintained flashing will lead to leaks and expensive repairs. Remember, the strength of your complete roofing system can only be as strong as its weakest link.
Signs Your Flashing May Need Repair
Although your flashing should be able to last for years, it cannot be completely maintenance-free. Exposure and natural roof movement can compromise flashing.
If you notice any of the following problems, have roofers check your flashing:
- Water spots on a ceiling or wall. These marks can indicate that your flashing is not properly sealed or secured. You will likely find these spots near a chimney, skylight, or external wall.
- Flashing that is rusty.
- Loose flashing. This is a common problem that can be a result of high winds or improper installation. Missing flashing can also pose a problem.
- Damaged or missing sealant around certain types of flashing can allow water into the roof structure.
- Peeling paint or damaged trim. These issues can result from water intrusion due to faulty roof flashing, particularly along a roof edge.
- Water leaks found around chimney areas or near roof vents and skylights.
The most likely cause of these issues is damaged flashing, but the problem could also be damaged shingles, ice, or excess condensation in the attic. The only way to be sure that the flashing is to blame is to have a professional roofing company look at the site.
Can You Repair Flashing, or Does It Need Replacement?
Whether you can repair flashing depends on the extent of the damage, the quality of the installation, and the condition of the other roofing materials.
In some cases, flashing can be repaired if it is only slightly damaged, such as when a few of the flashing pieces are loose but the rest are in excellent condition. However, if it is severely rusted or was improperly installed, the flashing should be replaced.
Sometimes you have to take the shingles around it off to get to the flashing and replace it.
Additionally, when it comes to flashing repair for a leaking joint, you should not use roofing cement or caulk for long-term maintenance. Sealing should not be used as a substitute for roof flashing even though it plays an important role in roofing.
A professional roofing contractor can assess the situation and determine whether they can repair the roof flashing or if they should replace it.
Replace Roof Flashing When You Replace Your Roof
A roof replacement is a great time to check all existing flashing.
While you can reuse some metal flashing if it is in excellent condition and fits current requirements, it’s usually best to replace it, especially around chimneys, along walls, in roof valleys, and anywhere else there are roof penetrations.
You don’t want to reuse worn-out flashing with new shingles because you’ll regret it when your new roof leaks due to an old flashing.
When you get your roof replacement estimate, ask the roofing contractor if it includes flashing replacement and installation. This will help you understand what flashing will be done as part of your roofing job.
How to Maintain Flashing
Although flashing is designed to be weather resistant, routine maintenance of your roof can prevent costly problems down the road.
Here are a few ways to protect your flashing:
- Schedule regular roof inspections. Make sure the flashing is secure and not decaying, especially after a major storm.
- Keep gutters clear. Clogged gutters cause water to back up along the edges of your roof.
- Check for visible damage. From the ground, look for displaced metal or other visible concerns around the location of the chimneys and roof openings.
- Repair leaks quickly. Even small leaks can cause irreparable damage if left alone, especially during freezing winter nights or heavy rains.
- Use a professional roofing contractor. Always call in a professional roofing contractor to inspect and repair flashing.
It is a good idea to do some maintenance before winter, when snow and ice can make roofing problems more difficult to locate and repair.
Protect Your Home With Properly Installed Flashing
Roof flashing is a small piece of your roofing system but has a big job protecting your home. Roof flashing safeguards roof joints, openings, and transitions, preventing water from getting in where it shouldn’t.
No matter if you are installing a new roof, replacing shingles, or need to quickly respond to a roofing emergency, make sure that you don’t overlook the flashing during the project.
Robert Evans Roofing knows the challenges that New England’s climate can pose for your home’s roofing and can help you decide what course of action is best for your specific situation.
Call Robert Evans Roofing to set up an appointment for a roof inspection or to talk over your roofing and flashing repair or replacement needs.
