What is flashing and Counterflashing? Counterflashing, also referred to as “cap” flashing, is the first line of defense against water infiltrating your building. Counterflashing is the piece of metal that is applied to the masonry wall designed to shed water off of the wall and down onto the roof surface.
What does counter flashing look like?
The concept of counterflashing is simple: a second (upper) layer of protection is provided to keep water from penetrating behind the first (lower) layer. If you are into analogies, it is like extending your pant legs over your rain boots. Your rain boots are the base flashing, and your pant legs are the counterflashing.
What is step and counter flashing?
What is step flashing and counter flashing? Counter-flashing: Placed opposite to base flashing, or above base flashing, counter-flashing completes the two-part team. Step flashing: Step flashing is a rectangular piece of flashing bent 90 degrees in the center. It is used for roof to wall flashing.
Does counter flashing overlap step flashing?
The flashing should extend away from the chimney, past the base or step flashing, before taking a sharp bend downward to create a capillary break, an air space that will not allow capillary suction of water from below. The base of the counterflashing should include a hemmed drip edge to manage the water ( Figure 12 ).
What is counter flashing on a roof?
Types of Flashing
- Base flashing. For front end-walls where roofing shingles meet siding, the metal flashing strip should be bent, using a metal brake, to extend at least 2 inches up the vertical ...
- Step flashing. ...
- Counter flashing. ...
- Continuous flashing
- Valley flashing. ...
- Drip edge (flashing)
- Type C. ...
- Type D. ...
- Type F. ...
- Kickout flashing. ...
What is Counterflashing apron flashing?
The base flashing (or apron flashing) is the bottom piece. Counter-flashing: Placed opposite to base flashing, or above base flashing, counter-flashing completes the two-part team. Step flashing: Step flashing is a rectangular piece of flashing bent 90 degrees in the center. It is used for roof to wall flashing.
What is the purpose of Counterflashing?
Counter-flashing is designed to prevent moisture from entering behind the vertical flange of headwall or sidewall flashing. Sometimes, the exterior wall-covering material serves as the counter-flashing, and sometimes a separate counter-flashing might be installed.
What is chimney flashing?
Chimney flashing is a type of roof flashing that creates a waterproof seal to protect your chimney and roof from water damage and penetration.
What is flashing in roofing terms?
Flashing: Pieces of metal used to prevent seepage of water into a building around any intersection or projection in a roof such as vent pipes, chimneys, adjoining walls, dormers and valleys.
Is roof flashing necessary?
It's a crucial roofing material that every roof needs to have. You'll have different metal options to choose from for your roof flashing. These common types of metals are aluminum, steel, or copper.
Is flashing galvanized?
Flashings are used in transition areas for roofing and gutter applications and divert water from one area to another.
What is flashing on a house?
As all builders know, flashing is a thin sheet or strip of water-resistant material that's installed at roof intersections and projections, around windows and doors, and along the tops of foundation walls to direct water flow away from the home. Flashing guides water out from the drainage plane to the exterior.
What are the different types of chimney flashing?
There are four main types of flashing that work with a masonry chimney:Step Flashing. Step flashing is the flashing that is incorporated into the shingle. ... Counter Flashing. ... Crickets. ... Smaller crickets may be installed that are covered with metal flashing materials. ... Rubber.
How do I install flashing?
1:343:29How to Install Roof Flashing on a Shingle Roof - IKO - YouTubeYouTubeStart of suggested clipEnd of suggested clipDo not fasten the flashing shingle to the vertical wall. This will allow the flashing shingle toMoreDo not fasten the flashing shingle to the vertical wall. This will allow the flashing shingle to move with any expansion. And contraction that may occur with the roof deck.
What material is used for flashing?
What materials are used for flashing? Flashing can be made from many different materials, including metal (copper, aluminum, stainless steel, lead, etc.), plastic, or composite materials. The most durable (and, therefore, most expensive) flashing material is metal sheet flashing.
Does flashing go over or under shingles?
Flashing should overlap the roof-covering material, but on asphalt shingle roofs, for aesthetic reasons, the part of the headwall flashing that extends down over asphalt shingles is often covered with a course of shingle tabs.
How much does flashing on a roof cost?
Generally, the cost of fixing flashing is anywhere between $15 to $25 per linear foot, which includes both the price of the new flashing itself and the caulking used to seal it in place (which is about $10 on its own or sometimes more). A total flashing replacement might cost anywhere between $300 to $600.
What is Roofing Counter Flashing
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.
Why is Counter Flashing Important
Counterflashing helps to protect the roofing below, typically asphalt shingles or clay tiles, from being damaged by water coming off the upper layers of the roof. counterflashes are installed on sloped roofs beneath chimneys and other protrusions like dormer windows.
Where is Counter Flashing Installed
Counter-flashes are installed on sloped roofs beneath chimneys and other protrusions like dormer windows. They are important because they help to keep the water out and protect the roofing below from any damage. counter-flashing can be made out of metal or any rigid material such as brick or plastic sheeting.
Roofing Counter Flashing Materials
Counter-flashing can be made out of metal or any rigid material such as brick or plastic sheeting. It can also be made out of plastic sheeting. counter flashing is often installed beneath chimneys and dormer windows to prevent water from the upper levels of the roof from infiltrating below.
Where counterflashing is most commonly used?
The counterflashing found on sloped roofs is used to protect asphalt shingles or clay tiles from damage by water coming off the steeply-pitched upper level of the roof. counterflashing is installed beneath protrusions like chimneys and dormer windows.
How far away should downspouts be from chimney?
Clean out the gutters and make sure the downspouts extend 6-10 feet from the home. You have the counter flashing which is directing the water away from the chimney so make sure the gutters are clean and the water can flow down and away from the home.
What is the purpose of counter flashing?
The purpose of the counter flashing is to sit on top of the base flashing to make sure water doesn’t go past it and instead flows down the roof or through the gutter.
Why do you need to know about counter flashing?
You might be wondering why you need to know about counter flashing? Well, if your home has any brick on it, you want to make sure that counter flashing was used in the construction process. Counter flashing is often used to flash chimneys, which means to divert the water away from the chimney and down the siding.
Where is counter flashing needed?
Conclusion. Counter flashing is very important anywhere you have brick on a home. This is usually on the roof and chimney areas. With this in mind, sometimes it is not installed or it wears out quickly and needs replacing. In general, the idea is to always keep water outside of the home.
What to do if water is coming into your house?
When to Call a Professional. If you notice water coming into the home or issues on the roof or near the chimney, call a professional for help. They can help with a diagnosis and also with answering any questions you may have.
How long does aluminum last?
Aluminum can last for 20 years or more when taken care of properly. Pieces can be cut so they are custom-fitted and slide together. Some people will paint it and it is corrosion resistant. Equally important, it is the least expensive of the three materials.
Do roofers install flashing around vents?
Roofers will install flashing around vents, skylights, and chimneys. Let’s take a look at why you need to know about counter flashing, what it is, problems with it, common materials used, installing it after building a chimney, common cause of roof leaks, maintenance, and when to contact a professional.
What is counter flashing?
is that counterflashing is (construction) formed metal or elastomeric sheeting secured on or into a wall, curb, pipe or other surface, to cover and protect the upper edge of a base flashing and its associated fasteners while flashing is (roofing) components used to weatherproof or seal roof system edges at perimeters, penetrations, walls, expansion joints, valleys, drains and other places where the roof covering is interrupted or terminated.
What is construction sheeting?
(construction) Formed metal or elastomeric sheeting secured on or into a wall, curb, pipe or other surface, to cover and protect the upper edge of a base flashing and its associated fasteners.
What is batten seam flashing?
The top of the roof pan is formed into a "bread pan" whose upper edge is just above the finished batten. Copper flashing is locked into this edge, and extends at least 8" up the wall. A copper receiver holds the counterflashing at its top edge.
What is copper flashing?
Description: Copper flashing is used wherever a wall intersects a roof. Such a system usually consists of copper counterflashing and base flashing in conjunction with roof composition flashing or coping. The counterflashing diverts water to the base flashing, which, in turn, diverts it to the composition flashing. The base flashing is designed to accommodate building movement. It laps the composition flashing at least 4". The composition flashing is extended up a cant strip then up the wall at least 10".
How far up do copper pans go on a roof?
The copper roofing pans are turned up on the vertical wall to form a base flashing extending at least 9" up the wall where they are cleated. Copper flashing, held by a receiver at the top, is locked into a locking strip soldered to the base flashing. The counterflashing overlaps the base flashing by at least 4".
What is flashing in masonry?
Flashing is a thin material used to prevent water penetration by providing a seal at joints exposed to the weather. There are two general types of flashing used in masonry construction. The first is external flashing (exposed flashing) and the second is internal flashing (concealed flashing). External or exposed flashings prevent moisture ...
What material is used for flashing?
Materials used for flashing include copper, galvanized steel. lead, aluminum, stainless steel, bituminous sheet material, and plastics. In some cases a combination of these are used, such as galvanized steel covered with bitumen that prevents corrosion of the steel when in contact with mortar. Concealed or external flashing is typically made ...
How far above the waterline should flashing be installed?
Base flashing typically extends 8 to 12 inches (205 mm to 305 mm) above the highest anticipated waterline. A cap or counterflashing is also typically installed so that it laps the base flashing at least 4 inches (100 mm).
Why do you need flashing on a roof?
Whenever the continuity of a roof covering system is penetrated, flashing is required to prevent water infiltration through the opening. Some common locations are where vent pipes, roof drains, roof vents, or skylights are installed. In addition, any future columns or steel angles used to support signs, flag poles or other items require flashing.
How are flashing types categorized?
Flashing types are categorized by how they are installed, either internal (concealed) or external (exposed). They can also be categorized by the material they are made from or by location: what part of a building they are installed in.
What is flashing in sheet metal?
When selecting flashing, it is important to take into consideration the durability, appearance, and potential galvanic action due to contact between different metals. Flashing is generally included in sheet metal specifications, which may include scuppers, gutters, downspouts, skylights, and decorative items.
How long is a lap on a roof?
Lap lengths of flashing at ridges are typically 4 inches (100 mm). At valleys, lap lengths vary depending on the slope and material of the roof. At slopes of 6:12 or greater, a 7 inch (180 mm) minimum lap length is typically used, while at slopes less than 6:12 a 10 inch (255 mm) minimum lap length is used.
Types
Formation
- The waterproof membrane laid down before the shingles forms the first layer, called the base flashing. This membrane attaches up the side of the wall as well.
Construction
- Next, L-shaped pieces of metal, typically aluminum, are placed under each shingle that butts up against the vertical wall. One side of the L-shape lays under the shingle, and the other side attaches to the side of the wall. This layer is called the step flashing.
Appearance
- In contrast to step flashing, the next layer is installed in a continuous strip. It sits on top of the finished roof and covers the step flashing. This final layer is called counter, cover or cap flashing and commonly consists of aluminum, galvanized steel, copper, tin or even plastic.
Advantages
- Depending on the construction situation, a step flashing roof is sufficient; vinyl siding can double as counter flashing as long as the step flashing goes underneath it. Otherwise, counter flashing is a critical requirement. Although it is more expensive and invasive than surface-mount flashing, reglet flashing does not need maintenance and thus represents a more convenient option.
Safety
- Surface-mount flashing attaches directly to the exterior materials. It is the least expensive installation method but also the least likely to be fully watertight. Caulk forms the seal at the top of surface-mount flashing, and this may need to be monitored and repaired or replaced over time because the caulk will inevitably break down.
Variations
- Reglet flashing represents a compromise between through-wall and surface-mount flashing. A cut is made into the exterior masonry at a 90-degree angle. The flashing material is secured in this groove and bent down to run alongside the exterior wall. Reglet flashing makes it impossible for water to get between the top of the flashing material and the exterior wall.