When you buy a home, you might as well buy a dictionary along with it. For many homeowners, there is an entire glossary of home construction, maintenance, and terminology that is essential to know. Among the many home components worth getting familiar with is flashing. 

What Is  Flashing?

Flashing is a material which goes between certain parts of your home to keep water from getting in. Most commonly found in roofing and siding, flashing is a supplement to your home’s resistance to the elements. It is one of the many ways a home can be weatherproofed and is one of the most important but under-considered elements to a dry indoors.

Let’s take a look at the different locations flashing calls home.

Types Of Flashing

Not every house needs the same amenities, and the same goes for flashing. Here are some of the most common forms of flashing that are used in everyday residential projects.

Continuous Flashing

One of the most common forms flashing takes, continuous flashing is applied in an unbroken strip across the desired location. There is some debate regarding the definitive uses of continuous flashing vs. step flashing, with both being applicable in a few similar construction situations. Step flashing is often seen as a superior option, but nevertheless, continuous flashing still sees its fair share of use throughout the roofing and siding industry.

Step Flashing

The design of step flashing mimics a step in a staircase; two pieces of flashing, one vertical and one horizontal, that connect to form an L-shape. This flashing is used on corners and edges to prevent water intake. Despite the debate with continuous flashing, step flashing is just as critical and often the more appropriate flashing option.

Valley Flashing

This kind of flashing is used along the borders of two connecting roofing systems, ie. the space where the roof above your living room meets the roof above your garage. This flashing is shaped like a capital “W,” and fits snugly over the valley connecting the two roofing systems.

Saddle Flashing

This kind of flashing is used for extended joists, beams, or pipes which pop out from the building envelope. Saddle flashing is one of the more specific kinds of flashing options out there and does not have as much versatility as continuous or step flashing.

Cap Flashing

This kind of flashing is also in the form of an L, similar to step flashing. Cap flashing is used primarily around areas where building wall or roof meets with a window and is used to redirect water runoff away from the home.

Roof Flashing

Let’s take a look at how flashing manifests on your roof.

Flashing is one of the most important elements within a home’s roofing system. While some homeowners may think the roof works like a lid on a pot, the truth is there’s a lot more to it than a simple cover. Roofs are comprised of a multitude of layers and ingredients, with flashing playing one of the biggest roles: keeping water out.

Predominantly used on the joists of the roof, the flashing prevents moisture, debris, and other contaminants from entering through the roof layers at some of their most vulnerable points. Roof flashing is generally made of either zinc, copper, PVC, stainless steel, or aluminum.

A roof’s flashing is one of the primary deterrents for water runoff, often helping direct liquids away from sensitive creases in a roof where it connects with protrusions like chimneys, windows, exhaust vents, and other HVAC system components.

Common Roof Flashing Locations

Chimney Flashing

As one of the most common roofing additions — especially since they protrude from the roof itself — chimney flashing is a must-have. Metal and PVC flashing is most commonly used for chimneys to keep water from entering through the space between the chimney brick and the shingles. Many chimneys use a combination of continuous and step flashing to help control water intake from all directions of access.

Chimney flashing is often installed slightly differently from other roof flashing methods, as the chimney itself is a sort of unique protrusion from the home. Since chimneys can come in many different materials (brick, metal, stucco, etc.) and can be used differently from house to house (frequently, unused, multipurpose), there’s a lot of variance in their flashing requirements. This is also a reason why chimney flashing is one of the most common sources for leaks in a roof; with all the different installation methods, some installers simply don’t do it correctly the first time.

If you’re easily and safely capable of inspecting your own chimney’s flashing, keep an eye out for rust, loosely installed flashing plates, and general damage. If you’re not 100% confident getting up on your roof to inspect it yourself, it’s always worth contacting a contractor for a professional opinion.

Skylight Flashing

Skylights are particularly at risk for water intake, as many of them are designed to be an inset of the roof itself. This design lends itself to pooling, and flashing is an excellent combatant for this problem. Skylights tend to use continuous flashing around their frames, with a possibility for saddle flashing as well.

There are a few different ways that flashing can be configured with a home’s skylight, and it is not uncommon to see some creative solutions arise to keep water out of a home. Some installers will wrap flashing around the skylight’s corners, while others will not. Some contractors may raise the skylight curb to provide a higher protective wall around the glass and allow for easier flashing installation. There isn’t one perfect method for ensuring good flashing installation, as the best method may vary from house to house.

Vinyl Siding Flashing

Good news for homeowners with vinyl siding: you can cross-reference your preferred flashing option with this document to see if it works with your building.

Window Flashing

Window flashing is one of the most important locations for flashing to be installed. As a typical culprit for moisture infiltration during rainy weather, flashing in these locations is essential.

One of the most common errors when installing window flashing is a negligence of the nail flanges on the window.

The flanges are the strip of material where the nails are screwed into the home’s vinyl siding. If the flashing does not surpass these flanges when installed, you run the risk of water seeping in through the window frame.

Another issue which often arises is the initial contractors over-trusting the siding itself to keep water out of the wall cavity and the home’s indoors. Siding and windows need to work in conjuncture with each other to maintain a dry indoor environment, but when installers assume the siding itself will be perfectly watertight, it’s not uncommon to see improperly flashed windows as a result. If leaks are continuously coming in through your window, there’s a chance it’s the fault of bad flashing installation.

Deck Flashing

Decks are especially prone to water damage, and as such, need good flashing to keep them dry. While porches, sheds, and garages are similar home extensions with weather exposure, decks are often uncovered from the elements. On top of that, your typical deck may be elevated off the ground on the stanchion, meaning wood rot and mold could contribute to an eventual collapse of the deck itself. It is for these reasons that home contractors take deck flashing so seriously.

One of the main areas of flashing focus on a deck is the ledger board. The deck’s ledger board provides a lot of the structural integrity and strength the deck has; freestanding decks do not have these, but many decks are structurally dependent on the home they are attached to, and thus need ledger boards.

Deck flashing will often be placed underneath the siding connected to the deck itself. As rainwater, snow, or general moisture runs off the deck and onto the home, the flashing will ensure it does not seep into the interior home or the wall cavity.

Get Your Flashing Inspected

If you’d like to have experienced professionals inspect your home’s ability to resist the weather and avoid moisture, contact Longview Contracting today. We’ll start discussing how we can help you solve your home’s needs.