Commercial Roof Flashing System Failure Causes and Reasons Not to Ignore It

The Valcourt Group | Dec 02, 2021

Commercial roof flashing can prevent water leaks and damages from occurring on a building and leading to more complex and costly issues. Repairing or observing roof flashing has a lot smaller price tag than paying for an entirely new roof. Looking at the difference price-wise between the two,  “The cost of roof flashing repairs is also subject to the total cost of the roofing repair as a whole, and if the whole roof requires replacement due to flashing system failure, technically the flashing repair becomes an $8,000+ cost for a flat roof or around $7,000 for shingled roofs. It’s all subject to the type of roof on the commercial building and how extensive the commercial roof flashing system failure is, explains Forbes. Keeping tabs on the roof flashing system can be difficult to remember, but handling the outcome of not keeping a close eye on the flashings is even worse. Not noticing the damages and failures in roof flashings can lead to water leaks, water damages, and potentially the need for a new building structure.

What Are Commercial Roof Flashings?

Flashing is a material installed to direct rainwater and other precipitation away from the roof and into the gutter to prevent water from causing issues. Some roof areas have a higher chance of causing a leak, especially where the water collects and sits, like valleys where two roof slopes meet. Due to the potentially extreme damage water can cause, flashings get installed at every point where the roof joins another structure—including chimneys, dormers, skylights, and vents. Commercial roof flashing can protect the roof from forming a leak, leading to needing a new structure on a house if left untreated. 

Installing commercial roof flashing can be quite time-consuming due to the many different steps required. Usually, experts install flashing during the construction of a building and complete it before the siding goes up, so the flashing will usually not be noticeable. Additionally, that means for a repair job to be done on the flashing, the siding must get removed to reach the actual flashing. Proper flashing installation requires a professional, and before starting, they will see if the wall receiving flashing has a corner on the roof face. This will alter the installation process due to different pieces being made to fit the edges of the corner. Depending on what aspect the flashing will be against, for example, a plumbing vent, chimney, or if there is a wall corner or not, can alter the installation process and the materials used.

Materials Used For Flashings

Using the wrong material for commercial roof flashing can lead to failure and water leaks through the roof. Usually, determining which material to use for flashing comes down to a material that will not degrade from contact with another incompatible material and flashing material for roof flashing that is impermeable to water. 

  • Plastic and Rubber: This is often primarily used as caulking. Plastic and rubber are excellent water-repellents when applied as flashing.
  • PVC and TPO: Both PVC and TPO are popular types of roofing systems, and the same material can be used as incredibly effective and durable flashing.
  • Roofing Felt: Asphalt-saturated roofing felt can be used as flashing but is not as durable.
  • Aluminum: It’s durable, easy to form, and somewhat inexpensive. When left in contact with an alkaline material like concrete, or treated lumber, aluminum flashing will corrode.
  • Galvanized Steel: Not as durable as other options, but it is very inexpensive.
  • Copper and Lead-Coated Copper: More difficult to bend and form than aluminum but much more durable. Copper flashing is common with the installation of solar panel piping, wiring, and sensor connections.
  • Lead: Super-flexible and durable, lead is a popular choice in the roofing industry. There are some potential health risks, but the use of lead flashing continues, and when properly installed, can last up to 200 years.

Done properly, installing flashing can provide protection (and a sense of relief) against water damage and other serious issues. Rather than wondering what is roof flashing, educate yourself on flashing and the serious risks of ignoring flashing issues. That knowledge could save a lot of money and a building from needing a new structure.

What Are the Types of Roof Flashings?

To properly avoid roof leaks, damaged or improperly installed roof flashing must be accounted for and thoroughly examined. There are various flashes used and they will vary on the material used and when to use them. The roof flashing types include:

  • Ridge Flashing: This flashing is applied at the “peak” of a dually sloped roof.
  • Bargeboard: This is the flashing along sloped roof edges.
  • Wall Abutment: This is where roof edges meet walls.
  • Corner Flashing: This flashing is used where walls meet, and it runs from roof to floor.
  • Inverted Corner Flashing: This flashing is used when the corner of a structure meets a wall. Instead of wrapping around the corner like “corner flashing,” flashing is applied in an “inverted corner” from roof to floor.
  • Eaves Flashing: This flashing runs along the length of flat edges of a roofing system.
  • Drip Cill Flashing: This is the flashing that runs along the lower perimeter or at the foundation.
  • Valley Flashing: The point where two downward slopes meet is where valley flashing is applied.
  • Step Fashing: Commonly used in place of wall abutments or chimney and skylight flashing (on slopes), step flashing is the downward overlapping alternate layering of roofing and flashing material.
  • Metal Edge Flashing: Also known as “drip edge flashing,” installed around the perimeter of a roofing system to direct the flow of water off of it without entering the structure. 
  • Saddle Flashing: This flashing is used where joists meet walls or other support structures, wrapping around connection points to form a water-tight seal.
  • Vent Pipe/Exhaust Flashing: This flashing provides a water-tight seal at the point where the vent or exhaust pipe protrudes through a roof.
  • Cap Flashing: This flashing is usually composed of metal and shields the membrane base’s upper edges, flashing along the top of a wall or column.

Causes of Roof Flashing System Failures

When flashing failure occurs, the root cause is either  loose  or wrinkled flashing. Failures of this nature can occur due to extreme fluctuations in temperature, poor installation, and if the roofing plans were unavailable. If the flashing shows obvious signs of damage or deterioration, this can cause issues with the inner roofing structure and make it more prone to water leaks. Depending on where the leak leads to, a moisture buildup can occur and potentially affect the roof’s wooden structure to rot. If a leak goes unnoticed, this can weaken or compromise the entire roof structure of the building and potentially need replacing. 

Extreme Temperature Changes

A dramatic change in the temperature can cause the roofing to expand and contract. Due to this, the flashing may pull away from the roof, making it ineffective. This problem usually occurs around vertical dormers, parapet walls, story walls, and other vertical roofing surfaces.

Poor Installation

The most common cause of roof flashing failure is improper installation. Installing components such as gutters, flashing, and roofing should always be done by a professional. Hiring a professional, experienced contractor can save the time and money otherwise spent to replace the flashing from poor installation. 

Unavailable Roofing Plans

The flashing can also fail because the original specifications of the roof were not available during the replacement or repair. This can result in the wrong material, technique, or type of flashing used. A reliable roofer should be able to provide you with plans to help avoid flashing issues.

Settling Foundation

When commercial roof flashing has been attached to the foundation of a building, failure almost always occurs. With foundation issues in a building, the cracks and problems do not always show up automatically. The most common places to notice cracks in the foundation are within the door frames and near the roof. Cracks can happen when the house’s foundation and structure finally settle into place. Additionally, the flashing may become loose once settling occurs. If the building has a fireplace or chimney, the signs will be most noticeable in those areas. 

If a leak goes unnoticed or worse, untreated, this can affect the entire building by impacting the drywall inside the building. Moisture can seep in, saturate the building, and cause waterlogging. Serious health hazards could develop, including the formation and spread of mold and fungi. Additionally, due to the drywall losing durability and the added weight of the leak, the drywall will potentially collapse. To avoid replacing the entire building structure or just the roof, fix issues as soon as they arise. 

What to Do About Commercial Roof Flashing Failures

To ensure the commercial roof flashing is up to standard and working as designed, regular inspections and maintenance can help spot the signs of needed repair. Some companies can perform inspections on the roof to check further to see if signs of damage have started. To fix a flashing failure, first look for the signs that the flashing is not working or needs replacing. Check the flashing for damages or bending, corrosion or rusting, loose or missing nails, dried out or missing sealant, or loose flashing.  If any of those problems are present, it might be time to replace the flashing to prevent water leaks and protect the structural integrity of the building. 

Loose Flashing

Flashing will commonly have issues attaching to the foundation of a structure, resulting inthe flashing becoming loose quickly. Loose flashing can occur due to faulty installation or, more so, from problems with the foundation. Having a contractor look at the flashing can bring issues with the foundation to light, such as cracks or stress fractures. 

Wrinkled Flashing

If the flashing shows apparent signs of wrinkles, this usually is from the weather. If the area receives extreme temperatures, this can cause warping from constant contraction and expansion of the roofing materials. High temperatures and excessive heat cause the roofing to expand, and lower temps a bitter cold cause contraction. When wrinkling occurs, the flashing will shorten in length and expose areas of the roof that should have coverage. Once the exposure occurs, the water will have full access to the roofing system and quickly affect the building. 

Some may not have the opportunity to check the roof or roof flashings as often as they should. Rather than having to climb on the roof and look at the flashings, there are a few ways to tell if flashing failure occurs. Here are a few other signs to watch for that can signal the issue with flashing:

  • Rust: flashing can corrode over time and cause rusting to become visible. When the flashing shows rust, it will no longer protect the roof against water penetration and require cleaning, sealing, or even replacing.
  • Holes: Even the smallest hole could cause water to look beneath the buildings’ shingles and start to cause issues. Also, be on the lookout for small animals causing holes in the roofing. Holes will require new sealant before causing major problems.
  • Cracks, dents, and bends: Such damages can cause breaks on the galvanized coating on steel, which can cause rusting to begin if not appropriately treated.
  • Missing parts: Parts can come loose and come off the roof due to high winds or extreme weather conditions. Immediately repair or replace any missing pieces of flashing.
  • Leaks inside the building: Signs of water leaks or damages inside the house make it more apparent the flashing has issues. The first places to check would be the fireplace, windows, attic, and skylight for signs of leaks. 
  • Damaged shingles or siding: If there was an installation error with the flashing and water does not shed the roof through the gutter, the shingles may also show signs of water damage such as bending and darkening, especially closer to the flashing.
  • Mold or stains on fascia boards: Mold is a potentially dire health risk for anyone living in or visiting the building. Improperly installed drip edge flashing can lead to mold and water stains developing on fascia boards.

Improve Roof Flashing System Longevity by Partnering With The JOBS Group.

Flashing can protect a building from water damage and other significant issues through proper installation and care. Commercial roof flashing can provide peace of mind against water damages or the need for a new structure on a building. Proper installation and upkeep of roof flashings are vital to maintaining the waterproofing properties for longevity. Staying on top of the proper maintenance and inspection of buildings and flashing needs can be difficult to prioritize. Rather than falling woefully behind on essential tasks while trying to manage your building, choose a partner that can help. Contact Valcourt today to save your roof flashing and building. 

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