Roof flashing is material that is placed at points on a roof that are prone to leaks. These are usually joints between various items and the roof (skylights, chimneys, vents) or between different parts of the roof. Flashing is usually made of metals that are resistant to corrosion. It can also be made of plastic or other composites. Flashing serves to direct water away from the leak prone areas towards gutters or off the roof. Deteriorating roof flashing can lead to leaks and damage to the roof and the house below.

What is Roof Flashing and What Happens When It Fails [infographic]

Why Do Roofs Need Flashing

Flashing is material that is used to direct rainwater and other precipitation away from the roof and into gutters or off the roof. Flashing plays a vital role in maintaining the integrity of your roof. There are areas of your roof that are prone to leaks. These are generally areas where water collects, such as valleys where two roof slopes meet. Places where the roof meets another structure are also prone to leaks at their joints. Because of this, flashing is installed almost anywhere a roof joins another structure, such as a chimney, dormer, skylight, or vent.

Flashing protects your roof from leaks by adding another layer of material specifically designed to redirect water. Without flashing, or when flashing is damaged or deteriorating, the risk of leaks increases greatly. Leaks can have a cascading effect on homes, causing large amounts of damage well beyond the roof. If a leak is not noticed and fixed immediately, a home can experience water damage.

Damage from Leaks

A leak into an attic space can cause moisture to build up and seep into the wooden structure. This may weaken the structure and even cause it to begin to rot, causing further structural damage. This can require expensive repairs that involve hiring a contractor to remove and rebuild parts of your house’s basic framing.

Other water damage occurs when water comes in contact with drywall in a ceiling or wall of your home. Drywall soaks up water and can become waterlogged. Wet drywall creates a number of hazards. The wet drywall can serve as a breeding ground for mold and fungi. When spores form these molds and fungi are released into the air they can make people in the house sick. Removing such growths is not always easy. A water damage specialist will start by spraying some form of poison on the mold or fungus to kill it. After that, the section of drywall affected by the mold may have to be removed and replaced. If there is too much moisture in the area, the area may have to be sealed off and treated for days or weeks with a dehumidifier.

If a leak drips onto flooring it can damage the floors as well. Carpeted floors are at particular risk for mold growth. That is because the fabric of carpets and the padding material underneath act like sponges, soaking up water and holding onto it. This creates an ideal environment for mold and fungus growth. Wooden floors are also susceptible to damage from dripping water. Floors can be stained or otherwise damaged by the continuous presence of water.

What Happens if You Don’t Treat a Leak

Sometimes, if a leak goes unnoticed or untreated, the drywall can become saturated. The weight and loss of durability caused by all that water can cause the drywall to collapse. This means a hole in your ceiling, plus a mess of water, saturated drywall, and junk from inside your ceiling all landing in the middle of your floor. This can be a mess to clean up and can cause further damage to the area.

To avoid leaks and keep your home safe, it is best to make sure that flashing remains in good condition and is fully functional. Regular roof inspections can catch any damage to flashing and determine what repairs are necessary. Eagle Watch Roofing can perform seasonal inspections of your roof. Contact us to learn how you can be proactive and prevent damage before it occurs.

Types of Flashing

There are many types of flashing, but they all fall into a few broad categories. Materials used for flashing vary. By far the most common material is sheet metal. Roofers usually use galvanized steel for its durability. In some cases aluminum may be preferable. This is often the case with DIY roofing jobs, since aluminum is more easily bent and easier to work with. In some specific situations a roofer may use copper flashing. This is usually done for looks. It is most common on historic homes or homes with unique roofing materials, including roofs made completely of copper.

Another material that can be used for flashing it pvc plastic. This material is cheaper than metal and easier to cut and work with. However, it is not as durable. When exposed to sunlight over a long period, pvc plastic tends to break down. With pvc plastic flashing it may be necessary to monitor the condition of your flashing and repair or replace it as it deteriorates.

Some flashing is now available made of synthetic materials and composites. These materials are relatively new and have different properties. Often they are used for their durability or ease of installation. The professionals at Eagle Watch Roofing can provide helpful information on the latest materials and their benefits.

Where Flashing is Installed

How flashing is installed depends on where it is installed. The most basic type of flashing is the flashing that collects water in the valleys of your roof. These are the joints where two slopes meet. Flashing in these areas will be installed underneath the shingles on either side. When water reaches the valley it will flow off the shingles and into the gulley created by the flashing. From there the water is safely directed to a gutter, downspout, or simply off the edge of the roof.

Chimney Flashing

Another common location for flashing is around a chimney. Chimney flashing is actually a collection of several types of flashing. Continuous flashing, a single strip of metal (or another material) is installed along the base of the chimney where it meets the roof. Along the sides of the chimney, step flashing is installed. This consists of squares fo flashing that overlap, similar to shingles, and climb up the side of the chimney along with the slope of the roof.

Saddle flashing is like a little mini roof behind the chimney on the higher side. Also called a cricket, this is a ridged design feature. It directs water and debris to either side of the chimney. That way it does not backup and collect on the high side of the chimney.

Finally, where the top of the flashing meets the brick (or other material) of the chimney, cap flashing will be mortared or caulked to the chimney. This flashing is attached to the chimney at its top and its lower part overlaps the flashing below. The bottom edge of the cap flashing is molded to direct water outward and away form the step flashing. It keeps water from seeping behind the step flashing.

Other Locations for Flashing

Flashing is also used around vents in the roof. The type of flashing depends of the type of vent. This flashing is also commonly included with the vent hardware. The same is true of skylights. Skylights require flashing around the area where they meet the roof. The flashing is often integrated into the design of the skylight. If it is not, flashing must be installed to prevent leaks around the skylight.

If a house has dormers, flashing will be required where the vertical walls of the dormer meet the sloped roof. Like with a chimney, stepped flashing is installed along the vertical wall of the dormer following the slope of the roof. The step flashing will be capped with cap flashing that is attached to the exterior of the dormer. The base of the dormer will get continuous flashing and the peak of the dormer will get saddle flashing. The area where the roof of the dormer meets the rest of the roof will be treated like other valleys, with standard flashing that rests beneath the shingles on either side.

Roofing Work is Rarely DIY

Roofing work is almost never a DIY project. Working on a roof is dangerous, with the main danger coming from falls. Without proper equipment, the risk of falling can be even worse. If you are not familiar with working on roofs, it is best to bring in a contractor. Eagle Watch Roofing is experienced in roof repair and roof replacement. Contact Eagle Watch today to find out how we can help you with your roofing needs.