Roof Flashing Details

A picture showing drip edges flashing as a type of roof flashing
Example of flashing on the eaves of your roof. This type of flashing is known as drip edges flashing.

What is flashing on roofs?

This is a common question asked by many. We described what roof flashing is vividly in this discussion– under the section “damaged flashing”.

To summarize once more:

Flashing is simply impermeable material put on joints in your roof and construction walls. In order to prevent water from seeping in and bringing about serious damages to your home.

There are different types of material you can use for your roof flashing as we will discuss later on in this article.

First, let’s look at the purpose of flashing on a roof. And how it works. So you can understand its importance. And, why you should make an effort to ensure your roof flashing is always in good shape.

What is the purpose of flashing on a roof?

Flashing is essential when it comes to your roof because it offers protection from roof leaks and severe water problems that may arise.

It (flashing) also protects the internal sections of your roof from harsh weather damages. Therefore, it is critical for certain parts of your roof. Including the areas where your roof surface meets the walls (the front and side walls), the valleys i.e. the low sections where the slopes of your roof meet, the roof’s edges and any protrusions.

Roof protrusions where most homeowners install flashing include: Skylights, bathroom and kitchen vents.

How does your roof flashing work?

The impermeable material helps to direct water flow around your roof openings preventing water from getting in. And, destroying your home.

Commonly, you can install flashing material as thin pieces or one long piece (continuously) in roof openings.  Including the areas we looked at above. This way, flashing protects your roof- appropriately- at all times.

Without proper flashing- water can easily penetrate your home through the roof joints and openings causing structural damage and severe mold problems. Leaks from these joints can also weaken your entire roofing system.


By causing the building materials underneath to deteriorate. And, when this happens, you’ll be faced with serious water damages that are very expensive to repair. This is why you must make sure your roof flashing is always in good shape.

Which material options do you have for roof flashing purposes?

There are 6 types of material you can use for roof flashing purposes.

These 6 options include plastic, rubber, galvanized steel, copper, aluminum and roofing felt:


You can use Polyvinyl Chloride (Pvc) plastic as a waterproof flashing material. It is strong and durable. However, Pvc cannot be in close contact with asphalt making it an unsuitable flashing material for some roofs.


Rubber is a good material for flashing. Because it can adhere to the joints properly hence offer maximum protection for your roof.

The downside of using rubber as a flashing material is the fact that it is flammable. Therefore, it poses a serious risk for fire outbreaks.

Also, it is not the most long-lasting option you can make since rubber easily weakens and tears over time.

Galvanized steel

Galvanized steel is the most durable material for flashing to use.

Because of its robust nature, steel is extremely long-lasting, which makes it the most economical purchase you can make.

Galvanized steel is also rust-proof and requires very low maintenance. As a result, you can confidently leave this type of flashing unchecked for a while. Without worrying about damages or malfunctions.


You can only use copper roof flashing alongside copper roofing. Since such flashing is custom-made to fit each specific copper roofing system.


Aluminum is the most popular roof flashing material.

Most people prefer using aluminum material because of its malleable nature. You can bend aluminum flashing into any shape with little force. Thus, effectively protect roof or roof features with an odd shape.

Roofing Felt

Roofing felt looks a lot like tar paper. It is the foundation material that manufacturers use to make roof shingles.

As a flashing material, you are better off using roofing felt alongside another material. Because, the felt alone will not give your roof full waterproof protection.

Also, roofing felt is not very strong or durable compared to other materials that are readily available for you to use for flashing.

Roof Flashing Types

There are approximately 6 types of roof flashing all named after the place where one installs the roof flashing material.

Continuous Flashing

As the name suggests, you put continuous flashing as one long piece. Mostly, you can put this type of flashing on the joints where your roof slopes and attaches itself to the vertical walls.

Valley Flashing

Valley flashing offers protection against water damage that may arise as a result of water seeping into your home- through the sections where the two valleys of your roof planes meet.

Because it follows the shape of your roof valleys, you’ll find that valley flashing material takes the shape of a W. During installation, valley flashing is put on top of roofing felt within your roof valleys.

Drip Edges

You’ll find this type of flashing on the eaves of your roof.

Commonly referred to as edges, the eaves of your roof are the sections that overhang on the face of your walls. And, usually, protrude beyond the sides of your entire building. (As illustrated on the photo above)

Generally, you install drip edges flashing under the roofing felt- along these roof eaves. In order to prevent water from seeping or soaking underneath these edges.

Step Flashing

You can easily notice step flashing on your roof’s horizontal segments. And vertical roof fixture. Normally, you have to shape the material you are using for this purpose to fit the specific horizontal or vertical section of your roof.

It is best to install this type of flashing in an overlapping manner. So as to prevent water from getting behind and causing serious roof water problems.

Cap Flashing

Cap flashing material  takes an L-shape.

Because of its shape, you can always set it up to lie flat against your roof. Or, any other fittings in your home including your windows.

The L shape of cap flashing structures lets water run-off on the opposite direction. This prevents water from collecting in any cracks or around the areas where you put cap flashing.

Vent Flashing

Vent flashing appears like a cone. You fit it into your roof shingles to cover and protect pipes.

Saddle Flashing

You can easily use saddle flashing to cover thus protect railing attachments. And, protruding beams.

Good Examples of Flashings used by Homeowners

Common examples of flashing you are likely to find in most, if not all, households include chimney flashing and skylights.

Chimney flashing

Chimney flashing is installed around chimneys. To prevent water from collecting within the gaps found between your roof and chimney bricks.

Often, home owners prefer using PVC or metal flashing material.

For this purpose, you can install different types of flashing. You’ll notice, most homeowners prefer using continuous flashing across the bottom area of the chimney. While covering and protecting its sides with step flashing.

You can also caulk in cap flashing to overlap the other types of flashing you use around your chimney. As a way of preventing water from running behind these flashings. This protects your home from any form of water damage that is likely to arise from your chimney area- fully.

Roof windows or Skylights

Skylights have an in-built flashing preventing water from oozing in. However, most homeowners add their own flashing for maximum protection.

Often, homeowners choose to fit continuous flashing along the roof window’s base. On the sides, they install step flashing while using saddle flashing to cover and protect the top part of the roof window.

Final thoughts

Is roof flashing necessary?

Often, the necessity of something in this life depends on your own needs and wants. Try not to confuse the two- your needs and wants.

In fact, it is important that you make an effort to always separate your needs from your wants. At each and every moment in your life. So you can maintain order and organization in your mind. This will help you gain clarity and peace of mind.

And, mental clarity and peace of mind results in clarity and peace in your external endeavors and life in general.

Once you have these two- mental clarity and peace of mind– you (more or less) already have everything.


Quite literally, you can work towards and achieve any thing under the sun-with a clear mental state and a peaceful mind. This could easily be, how the few individuals, others use the term- force to be reckoned with-on, create themselves. By first-actively working towards gaining and maintaining mental clarity and peace of mind.

Then, proceeding to be great forces in the areas of their own choosing. And you can always do the same. Talk about the beauty of human nature, huh? – That, you can- continuously-achieve anything that you properly set your mind to.


When it comes to your roof flashing, you really don’t have the luxury of deciding whether it is necessary or not. It is one of those things where the decision has already been made for you. The same goes for most things/ issues regarding buildings and constructions.

In short, roof flashing is necessary. Because, this form of protection for your roof is a required practice in construction. As a result, it is applied widely to all structures be it residential, commercial or industrial buildings.

In addition, note that flashing is not just installed on your roof. You can also set up flashing in other parts of your home as well.

For instance- You can install flashing above all interior wood trims, on top of shelves, windows and doors. And, in the sections of your household where outdoor decks and stairs attach to the house.  Flashing is also mounted underneath the first course found above ground level within a masonry structure.

Over to you:

What is the condition of your roof flashing? Do you have any regular roof maintenance practices that have worked well for you so far?

Remember: taking good care of your home is taking good care of yourself and your loved ones.

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