Roof Flashing – Importance & Types

While not all roofs are the same, they all need some type of flashing. After all, most roofs have a chimney, vent pipes, dormers and all these areas where two inclined – vertical and horizontal, sections meet, the exact parts water may pool and gradually find its way into the home. That’s where flashing comes in – to protect and leave the interior of the home intact from water leakage and seepage. So, let’s answer some questions to see the great importance of roof flashing.

What’s roof flashing, anyway?

roof systemFlashing is one major component of the roof system. It’s a piece of metal, which is installed at joints and seams to direct rainwater away and thus, prevent indoor leakage.

Since flashing is part of the roof system, it is made of moisture/rust resistant metals, like galvanized steel, copper, and aluminum. While most homes have steel roof flashing due to its modern look and affordable price tag, copper outperforms any other metal material but it’s also the most expensive.

Roofers may nail flashing but since holes should be avoided, they more often than not, adhere flashing with roof cement – hence, creating a solid seal between the flashing sheet and the roofing material.

As we have already said, the job of flashing is to seal sections of the roof where two materials or two different heights intersect, like valleys, skylights, chimneys, rakes and eaves, etc. And so, there are different types of flashing to meet all these needs.

Types of roof flashing

Since roof types vary significantly in terms of size, style, steepness, and components, each has different needs in regard to flashing.

•   Base flashing is needed where the roof meets a vertical surface, like a wall, the chimney, etc.

•   Step flashing is required when there’s a ninety-degree angle between the roof and the dormer, for example.

•   Valley flashing is installed at roof valleys, as their name implies. These are the areas where two roof slopes meet, creating a valley.

•   Drip edge flashing is placed at the edge of roofs to protect the fascia, the siding, etc. The flashing types are identified by their shape in order to properly cover the intersecting parts required.

Is it time for roof flashing replacement or not?

roof flashing replacementA roofer will tell you if there’s a need for roof flashing replacement, based on the condition. As it is often the case, most flashing sheets last for a very long time. This simply means that there’s not necessarily a need to replace the flashing when replacing shingles. Of course, the roofer must thoroughly check the condition of the flashing and determine whether or not it is important to install new flashing, based on the current one’s lifespan too. Naturally, if there are damaged sections, the flashing should be replaced. As a matter of fact, this becomes an urgent matter when – for some reason, the flashing is ruined and there’s a possibility of water pooling at the intersections.

In this context, let us examine the following.

Which are the signs screaming the need to replace flashing?

There are some telltale signs indicating flashing problems and thus, the need to find a roofing contractor.

•   The shingles become curly and show signs of damage, likely due to water ponds under the shingles.

•   Missing components – for example, missing bricks in the chimney, often due to flashing damage.

•   Stains on the siding or fascia – any sign of damage at all, indicating some dampness.

•   Gutter problems – clogging, sagging, rusting, etc.

The flashing sheets may also get curly, bent, and loose. This may happen due to poor installation, bad quality, heavy impact, or missing fasteners – or broken sealant.

Naturally, the more obvious sign that it’s time to do something about the roof flashing is to notice high moisture indoors, especially in the attic. Or even go through a water leakage. Of course, the whole point is to avoid getting to this point and so, it’s always best if you have a roofer inspecting the flashing from time to time.