Tag: condensation

Proper Ventilation for Metal Roofs and Walls

Posted on by David Lester

Selecting metal roof and wall panels is a strategic investment for the life of a building. To protect their investment, it is key that your customers ensure the proper ventilation system is installed. Optimal air movement not only promotes temperature regulation and energy efficiency but also reduces the risk of moisture-related issues like condensation build-up. Here, we look at some of the main ventilation considerations and resources your customers need to ensure success.

ABC Blog: Proper Ventilation of Metal Roofs and Walls

Why is proper ventilation important?

Proper ventilation helps optimize the performance and efficiency of metal buildings by:

  1. Controlling condensation

Condensation can wreak havoc on metal, causing corrosion, reduced thermal performance of insulation, mold and mildew growth, and even insect infestations. For example, in warm and humid areas, outside air that enters a building without moving through a ventilation system can bring with it large amounts of humidity. This humid air can create an uncomfortable environment, accelerate panel weathering and increase the possibility of mold growth. This issue is worsened when the outside temperature falls below the inside temperature, creating a perfect breeding ground for condensation development.

  1. Regulating temperature

Regulating and maintaining ideal interior temperature can help cool the building in warmer months, keeping the structure comfortable to occupy. Temperature regulation also helps protect the integrity of the building from excess (and premature) metal panel expansion and contraction. This movement can weaken the integrity of fasteners, which are designed to keep panels from detaching/pulling away from the substrate.

  1. Preserving air quality inside the building

Proper ventilation helps remove volatile organic compounds and other air pollutants that are detrimental to human health and productivity. The Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA) have published guidance on indoor air quality standards in commercial/institutional buildings. These standards help determine ventilation needs that need to be met to ensure compliance.

Who Needs Ventilation?

As expected, most structures require proper ventilation in accordance with their geographic location, contents and/or building end-use. Structures housing chemicals or moist substances require more ventilation than those storing dry goods in relatively arid environments. Ventilating a building that stores ceramic in the desert is very different than ventilating an indoor sauna in practically any geographic location. Agricultural facilities in particular must employ proper ventilation to mitigate the dangers posed by ammonia and other corrosive airborne fumes. (See our Animal Housing blog post for more.)

How to Ensure Proper Ventilation:

Similarly, the ideal amount and type of ventilation your customers need depends on their building’s unique specifications and end use. Generally, structures larger than 2,400 sq. ft. may require more than one type of ventilator to allow air to move between them (cross-ventilation). Structures that house people, animals and/or valuable material also benefit from cross-ventilation using ridge vents near the roof and a louver vent located closer to the structure’s floor. In these cases, it is recommended that your customers work with design professionals and building engineers who can help determine the building ventilation requirements. These professionals can recommend the appropriate, high-quality metal panels and components that suit the unique requirements of their project.

So, what ventilation options are available for your customers? Ventilation solutions fall into two main categories: natural (unpowered) and mechanical (electrically assisted):

  • Natural ventilation methods include installing a ridge and eave vents that enable air to circulate naturally through the building. Your customers can also use vents that capitalize on the natural vacuum created when air moves quickly over angled surfaces like roofs. The lower pressure in this vacuum draws air out of the building—most often through ridge vents. This choice will depend on your customer’s aesthetic preferences and/or installation location limitations.

 

  • Mechanical or power-assisted ventilation helps draw more cubic feet of air into and out of the space per minute. Powered fans with curved blades and/or louvers are often used to achieve greater air flow. As previously noted, air flow is vital in preventing condensation, so this is particularly helpful in naturally humid environments.

Conclusion

In conclusion, proper ventilation is a critical component of any high-quality building. As metal panels are becoming more popular, understanding how to achieve an effective ventilation system can help ensure the success of your customers’ building projects.

For more on ABC’s ventilation solutions, visit our previous blog on condensation management, check out our ventilation-enabling components or reach out to your local representative today!

A Simple Solution to Metal Panel Condensation

Posted on by Tyler Roose

If you’ve ever gone outside before sunrise, you’ve likely noticed dew on the grass or on your car windows. This is condensation. While we may have learned the basics of this naturally occurring phenomenon in science class, we may need a quick refresher.

Condensation occurs when there’s more water vapor (the invisible, gaseous phase of water) than the air can hold. When the water vapor is cooled off or compressed to its saturation limit—at which point the vapor’s molecular density reaches its maximum threshold—it turns into liquid. Warm air can hold more moisture, but as it cools it reaches its saturation limit and water droplets form. While not a problem on the grass or your car (once you wipe the water away), condensation on metal panels CAN be a problem for your customers. The good news is there’s a simple solution.

ABC Drip Stop for metal panel condensationWhat causes condensation on metal panels?

When temperature and humidity conditions reach dew point, moisture can condense on the underside of metal roofing and potentially cause water damage to the inside of your customer’s building. Those drips from ceilings and surface moisture occur when warm air comes in contact with the cooler roofline or walls.

High interior humidity—a common cause of condensation in metal buildings—can result from heating and air conditioning systems, how the building is used, gas-fired heating components, improper construction techniques or even human respiration, as these all give off moisture vapor.

Effects of condensation on different types of panels:

If there is an abundance of condensation, water droplets will form and can cause damage. In metal buildings, there are a few possible consequences of trapped moisture in wall and roof systems:

  • Corrosion of metal components, even on surface-treated metal: When exposed to moisture, metal components can oxidize and weaken, decreasing the life of your customer’s building.
  • Degradation/ reduced effectiveness of the thermal performance of insulation
  • Mold or mildew growth, which can cause unpleasant odors and increase health risks, particularly for those with allergies or asthma
  • Insect infestations

Note: The probability of significant problems will depend on the location and usage of your customer’s building.

Controlling Condensation: What is the Solution?.

Traditionally, condensation is managed by insulating the metal roof so that the panel temperature never reaches the dew point. This is often accomplished using vinyl-backed fiberglass insulation to prevent humid air from coming into contact with the cooler metal roof (which may be at or below the dew point). If your customers are heating or cooling their building, adding insulation is certainly worth consideration. If they aren’t, there is another option to consider besides the installation of vinyl-backed insulation.

Your customers can consider installing Drip Stop, a patented condensation control membrane, to prevent damage from moisture. Drip Stop (manufactured by ABC) is a felt-like material with a rubber backer that can be applied to the back side of metal panels. The material literally traps and holds the moisture resulting from condensation. When conditions change, the ambient air temperature usually rises, thereby raising the dew point. The moisture is then released from the Drip Stop material back into the air in the form of normal humidity. Drip Stop can be applied to the back of metal coils (either Galvalume® Plus or painted) and then the metal can be roll-formed onto panels.

ABC Drip Stop for metal panel condensation

What are the benefits of this alternative condensation control method?

Drip Stop offers several advantages for your customers:

  • Durability: Drip Stop is a very tough, light gray anti-condensation felt that is not susceptible to ripping, tearing or deterioration unlike standard insulation and vapor barriers.
  • Low Maintenance: Drip Stop resists dirt and grime, is antimicrobial and is very easy to clean with a hose or pressure washer.
  • Corrosion Protection: The rubber backer on the material helps protect the back side of the panel from corrosion (although there is no protection at the panel’s cut edges).
  • Easy to Handle: There is no need to roll a vapor barrier over purlins and then seal with tape, which can reduce labor hours and cost. Additionally, the use of Drip Stop is not hindered by windy conditions.
  • Safety and Insurance: The material is approved for smoke generation and flame spread per UL® 723 for insurance specifications.
  • Acoustic Benefits: Drip Stop helps dampen sound from either inside or outside the building.
  • Versatility: Drip Stop is approved for use in residences, warehouses, industrial plants, sports arenas, schools, storage buildings, garages, animal confinement facilities and more.
  • Cost-Savings: Drip Stop is up to 25 percent less expensive as compared to traditional solutions.
  • Warranty-Backed: Drip Stop features a 20-year adhesion warranty to ensure longevity.

The Bottom Line:

There’s no need for the damaging effects of condensation to put a damper on your customer’s metal building project. With a simple solution like Drip Stop, you customers can protect their assets and prevent costly and time-consuming repairs.

For more information on Drip Stop and how it can be applied to ABC’s PBR, Imperial Rib® and Retro-R® panels, visit our website or contact your local sales representative.