What Is Counter Flashing

Today I am going to tell you all about what is counter flashing in this article. There is a possibility of leakage and water loss in different areas of the roof or the joint parts of the roof. These include parts like roof valley, roof joint surface, chimney, skylight, counter flashing roof to wall, etc.

So protection is needed to prevent leakage in these areas. The only option is flashing. Roof flashing uses counter flashing, valley flashing, step flashing, headwall flashing, gutter apron flashing, etc. Thus, we can use different flashing inside our house or keep the chimney dry.

Let us know, what is a counter flashing. Understand its purpose and its importance.

What Is Counter Flashing?

Counter Flashing

Counter flashing is used on walls and chimneys. It is cut into mortar joints in brick masonry and placed on top of the brick.

Copper flashing is used in the part of the house where the wall and the roof join together. These include copper counter flashing and base flashing. The base flashing is designed to resist the movement of the building. The standard minimum weight for copper coping and counter flashing is 16 oz.

Copper counter flashing is used for built-up roofing with copper base flashing and composition base flashing. Which prevents the entry of water behind the composition base flashing.

Counter flashing roof to wall and drains the water flow in the right direction on the roof to prevent leakage. This flashing is always overlapped on the base flashing. So that the water does not go behind the flashing.

This flashing is made from materials such as aluminum, galvanized steel, and copper. 26 gauge steel is used for counter flashing.

Counter Flashing For Chimney Flashing Installation

Counter flashing is mainly used in chimney flashing. Chimney flashing installation begins with counter flashing installation. Counter flashing chimney.

  1. Proper marking should be done on the wall to install counter flashing for chimney flashing. Next, the mortar joints of the brick wall should be depth to about 2 inches using a suitable grinder machine.
  2. Now, 26 gauge steel is cut according to the size properly measured on the site for flashing.
  3. Then, the overlapping counter flashing is fixed with solder.
  4. The material should then be coated with acrylic to protect it from corrosion. Which prolongs the life of counter flashing.

Types of Counter Flashing

Counter Flashing Details are:

1. Brick Counter Flashing

First Method, install counter flashing with the copper receiver. In which the copper receiver is placed between the bricklayer in the mortar joint. The counter flashing is then connected to the edge of the copper receiver. This counter flashing brick wall prevents water in the chimney.

Brick Counter Flashing


2. Reglet and Counterflashing

The second Method, counter flashing, is inserted into the concrete with the reglet. The reglet Flashing is then sealed with sealant.

Reglet and Counterflashing


3. Exteior Counterflashing

Third Method is used for covering the outer wall. The top of the flashing is held up to the wall of the building by a 4-inch lap. This is shown in the figure.

Exteior Counterflashing


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Materials Used for Counter Flashing

The role of counter flashing attached to brick walls or brick chimneys is of great importance. Its material is in constant contact with wind, precipitation, and accumulating debris. Therefore, it is necessary to consider the material used as flashing in that situation. Three common metals used for counter flashing are aluminum, copper, and galvanized steel.

1. Aluminum Counter Flashing

  1. The most widely used material for counter flashing is aluminum. With proper care, the aluminum counter flashing has a lifespan of more than 20 years.
  2. This metal Counter flashing can be custom fitted and the pieces can easily slide over each other. If it is painted weatherproofing, it can be corrosion resistant.
  3. Aluminum counter flashing is the most important and least expensive material. However, there are some disadvantages as well as disadvantages. If the aluminum flashing is not properly maintained, direct contact with the mortar can cause corrosion of the aluminum flashing without paint.
  4. Since the material of aluminum flashing is lightweight and thin, it is weak. So it can be easily damaged. In addition, its contents cannot be soldered. So its pieces are placed together by overlapping. But even when it is fixed together by a nail, the joints can become weak.

2. Galvanized Steel Counter Flashing

  1. Galvanized steel counter flashing has strength and durability. If properly maintained, galvanized steel can have a lifespan of about 40 years.
  2. The joints between the pieces of galvanized steel flashing can be soldered. Which acts as one unit.
  3. It also has a tendency to corrode like aluminum flashing. Which, at worst, leads to tiny holes in the metal. Which leads to water infiltration.
  4. It, therefore, makes maintenance or repair of weak areas difficult. This material is heavier, thicker, and weighs more than other materials.

3. Copper Counter Flashing

  1. Copper counter flashing is extremely durable and long-lasting. It provides the most beautiful look in other metals.
  2. Its joints can be soldered, like galvanized steel, but the copper material is light in weight and extremely soft. So it can be given the right shape. In addition, it can be easily molded and installed.
  3. Copper is a good alternative for flashing. But it is the most expensive of the other metals. Since it is the most expensive metal material, it can be a target for theft.

Every homeowner should consider the cost, durability, maintenance, and strength of the material before choosing the material for the roof and walls of the counter flashing. It also takes into account the material of the roof.

Where Is Counterflashing Used?

Counterflashing on sloping roofs is used to protect asphalt shingles or clay tiles from water damage from the roof’s top layer. It is mainly used in places like chimneys and dormer windows.

It is advisable to hire a roofing contractor to properly install it in places like Chimney, counter flashing roof to wall, and dormer windows. Which helps you to properly install counter flashing.

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Frequently Asked Questions (FAQ)

Counter Flashing

Copper flashing is used in the part of the house where the wall and the roof join together. These include copper counter flashing and base flashing. The base flashing is designed to resist the movement of the building. The standard minimum weight for copper coping and counter flashing is 16 oz.

Counter Flashing Roof

Roofing counter flashing is the metal, usually lead or aluminum counter-flashing installed beneath roof penetrations. counter-flashing is used to keep water from penetrating through the penetration. counter flashing is typically located underneath dormer windows, skylights and around chimneys.

Counter Flashing Chimney

Counter Flashing is often used on chimneys or where the wall meets the ceiling. There are two layers: the first is the base and bottom of the chimney, and the second is embedded in the brickwork of the chimney. Counter flashing is installed on top of the base flashing to prevent water from passing over it and instead run down the roof or down the drain.

Counter Flashing Roof to Wall

Counterflashing is also known as “cap” flashing. It protects against water infiltration into your building. Counterflashing is a piece of metal applied to a masonry wall designed to direct water down the outside of the wall and onto the roof surface.

Surface Mounted Counter Flashing

A surface-mounted counter flashing system is provided to secure and seal the free end of the roofing material on the wall. The compression plate securely seals the free end of the roofing material against the wall surface.

What Is Counter Flashing on a Roof?

It is installed on top of the finished roof and covers the step flashing. This is called flashing the counter, cover, or cap. Aluminum, galvanized steel, copper, tin, or even plastics are commonly counter flashing materials used.

What Is Counter Flashing on a Chimney?

Counter flashing is installed in the mortar joints in the chimney wall. Its purpose is to seal the top of the base flashing. It should be installed with a saddle flashing, for chimneys wider than 30.

Counter Flashing Cost

The counter flashing cost can range from $ 750 to $ 1450 depending on the size of the chimney, the flashing material, the type of chimney, and the type of roof. If your flashing needs to be changed you should fix the problem immediately. But if the flashing of the damaged chimney is to be avoided, the roof can be further damaged.

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