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What Causes Condensation On Commercial Metal Roofs (And How to Treat With Metal Roof Restoration)

13 Feb 2018 | Under Metal Roofing | Posted by | 0 Comments
R&A Contracting - Commercial Metal Roof Restoration St. Louis

Anybody who has ever written a quickly vanishing message on a bathroom mirror after a hot shower is familiar with condensation. The hot steam from the shower turns to water droplets when it hits the cool surface of the mirror, allowing you to leave your momentary message. Writing a message on the bathroom mirror is certainly innocent enough. However, if you are a business owner or facilities manager and your building has a metal roof, condensation can be a major problem.

How Condensation Forms on Commercial Metal Roofs

As we often do in our blog, let’s take a trip back to our elementary school science class for a refresher on how condensation forms. Just like rain, condensation occurs when there is more moisture in the air than the air is capable of holding. The warmer the air the more moisture it is able to hold. Condensation becomes water droplets when the moisture in the air makes contact with a cooler surface, such as the underside of your roof. More specifically, water droplets are created when moisture in the air settles on the surface with a temperature that is cooler than the dewpoint of the surrounding air. The dewpoint is essentially the temperature the surrounding air has to lower to in order for dew or condensation to form.

The more humid the air in the building, the more condensation you are likely to have. The warmer the air, the more water vapor it is able to hold. That is why warmer temperatures typically go hand in hand with increased humidity.

At first, condensation may seem like a small problem or a nuisance. You may think it’s just a few drops of water and move on with your day. However, those ‘few drops of water’ can cause a tremendous amount of damage to your building and the equipment inside. If enough water droplets make their way into your building, you could have a major moisture problem on your hands. Repeated buildup of moisture can lead to a great deal of damage and expenses. Mold and mildew are typically the moisture problems building owners and facility managers are most familiar with.

However, excessive moisture can lead to a slew of other costly and challenging problems. Damage from repeated freezing and thawing can be a major problem if there is too much moisture in your building.

This can lead to pipes cracking and damage to other hard surfaces. Many people think that galvanized steel is immune from rust. Galvanized steel may be resistant to rust, but it is certainly not immune. With enough exposure to condensation even galvanized steel will begin to rust.

Two Forms of Condensation

All forms of condensation are not created equal. In fact, there are two forms of condensation, visible condensation and concealed condensation. Visible condensation is the form you are probably most familiar with. Visible condensation can be easily seen on pipes, windows, and other hard surfaces. Think back to the steam on the bathroom mirror. Visible condensation may take the form of ice or frost, or it could simply be water droplets.

Concealed condensation is the second and most problematic form of condensation. Concealed condensation occurs in situations where moisture makes its way inside of the building envelope and forms condensation on hard surfaces.

The Effect of Condensation on a Metal Roof

Metal and water don’t mix. You don’t have to be a chemist or engineer to understand water on the underside of your metal roof is a recipe for trouble. If water vapors continually gather on the bottom side of your metal roof it could lead to oxidation, which in turn leads to rust. Rust can lead to a catastrophic roof failure.

Roof damage from condensation could be difficult to spot. If you have some form of insulation on the bottom of your roof it may be difficult for you to spot oxidation when it is happening. The insulation or covering on the bottom of your roof could conceal visual indicators of structural defects.

If you examine your roof from the top, the outermost layer may show no signs of damage. Condensation could be destroying your roof from the inside out, and you may never find out until your roof is in need of repair.

Insulation Helps to Reduce Heat Transfer in Metal Roofs

If you ever touched something metal on a hot summer day, you know that most metals are excellent conductors of heat. Radiation, convection, and conduction are the three ways heat can be transferred.

Radiation: Heat is delivered in waves these waves move in straight lines. As the heat waves move through a space, they will heat up anything they come in contact with. The outermost layer of your roof being heated by the sun is a textbook example of heat transfer through radiation.

Convection: Convection is used to describe heat as  it moves through gases or liquids. Convection is what causes heat to rise and warm the underside of a metal roof. Because of convection warm air rises while cooler air sinks.

Conduction: Conduction describes heat as it moves through a solid material. A particularly relevant example of conduction would be heat moving through your metal roof and making its way into the interior of your building.

As you can see, all of these types of heat transfer play a role in causing condensation to develop on a metal roof. The space right below your roof is a prime target for all three of these types of heat transfers.

The Leading Causes of Condensation in Commercial Buildings

Finding the source of your moisture problem can be a tricky proposition. Typically, there are three sources of moisture that can lead to condensation problems, exterior moisture, interior moisture, and built in moisture.

Exterior moisture is the moisture source facility managers and building owners seem to be most familiar with. These moisture sources are environmental. Rain, stormwater, snow melt and groundwater makeup this particular condensation category. Issues from these condensation sources are going to vary widely depending on the physical environment around the building.

Stopping Condensation Once and for All

There are two basic ways building owners can stop condensation from forming on the underside of their metal roof. Keeping air circulating below the roof is the first option. If air is moving continuously, it will not allow condensation to form. This solution seems straightforward. However, it is very difficult and costly to develop and implement a HVAC solution that will keep the air moving and stop the formation of condensation.

Insulation Is the Key

Insulation is the number one approach for tackling condensation problems in buildings with metal roofs. Installing insulation is the best approach simply because it forms a physical barrier and does not allow moisture in the air to make contact with the cooler surface of the roof.

Not all insulation is created equal when it comes to condensation issues. The typical pink, fluffy insulation that many of us are familiar with can act as a barrier although, it is not an ideal solution. The fatal flaw for this type of insulation is that it is difficult to keep the area below your roof completely covered and sealed with conventional insulation.

Gaps and seams in the insulation will allow condensation to make its way through. Additionally, the insulation has to be able to keep the area completely sealed. Achieving complete and total coverage with conventional insulation is a tricky proposition.

On the other hand, the very nature of spray foam or SPF insulation makes it the ideal choice for creating a condensation blocking barrier. Spray foam is sprayed into place with a large gun during the installation process. Spray foam expands to fill the installation area. It forms a seamless, rugged membrane. This rugged membrane completely blocks moisture from co-mingling with cooler air. Spray foam is the best solution if you want to stop condensation problems once and for all.

Humidity Levels Vary Depending on Your Business’s Operations

Anybody who has ever enjoyed a summer in St. Louis can tell you we have more than our fair share of humidity. However, condensation problems can also come from moisture released into the air from activities inside of the building. It is not always an issue of ambient air causing the problem.

In many situations, humidity levels change based on the activities taking place inside the building. One common example of such a trend is machine shops or facilities that house a great deal of manufacturing equipment.

Anyone who has ever worked on the computer for a long time in the depths of winter or in the dog days of summer can attest that machines produce heat. You may have noticed that your computer can double as a heater in many situations. Now, think about a room full of big, industrial machines buzzing, whirling, and cranking out widgets and a serious amount of heat.

Heat raising is simply an inescapable law of physics. As the warm air from the machinery rises, it comes into contact with the cool underside of the roof. Upon hitting the cooler metal, the water vapor in the humidity condenses and forms condensation.      

In these types of situations, humidity is not just a problem in terms of water damage to the facility. Excessive humidity in machine shops or industrial plants can lead to equipment problems.  CNC machines are used by machinists to manufacture complex parts to exact specifications. Specifications for the parts made by the machines are typically measured in increments of a 1000th of an inch. Machines as complex and delicate as these often experience a higher failure level of internal components when the humidity in the facility is too high. Gosiger manufacturers internal components of CNC machines. They report their busiest time of the year for distributing replacement parts is in the summer when high humidity levels outside lead to excessive humidity and condensation inside the building. This can also lead to problems for furniture and other organic materials inside the building.

Condensation Can Negatively Impact Employees

We now know condensation can lead to damage to the facility and the equipment inside. But, there is one more important asset condensation can cause problems for. Condensation will lead to higher humidity levels. This in turn creates a serious problem for the living, breathing beings that make the business run.

As a facilities manager or business owner your number one job, above all else is to keep your employees safe. High humidity levels can cause your employees to become ill or develop a variety of heat and humidity related health issues. The health of your employees is certainly the most important thing to worry about if you are a business owner. Beyond this, the productivity of your employees will most certainly decrease if they are working in an extraordinarily humid environment.

Farmers and businesses responsible for the well-being of livestock also have to keep a close eye on the humidity in their environment. Just like humans, animals can become extremely ill if they are exposed to prolonged levels of high humidity. The temperature itself, is not the biggest threat to livestock. Most farm animals will be just fine even as the mercury spikes. Humidity levels create the biggest problems for animals. If the humidity levels are at 90% or greater animals will be at a significant risk of becoming ill.

Water is necessary to sustain life. Water vapor is an inevitable byproduct of many activities we must engage in to sustain life as we know it. Simply by breathing, human beings contribute substantial amounts of water vapor to the air around us. Water from our respiratory system is added to the air every time we exhale. As a result, buildings with a large number of employees may be more susceptible to condensation issues.

We Are Here to Help With Your Metal Roof Restoration

Business owners or facility managers who have metal roofs should not take condensation problems lightly. Condensation issues can leave you needing to replace your entire roof. At R&A Contractors we are experts with metal roofing and foam insulation. If you have a condensation problem we specialize in the tools necessary to solve that problem quickly and efficiently.

If you have condensation issues or suspect you may have, give us a call immediately. Our roofing installation experts will be able to quickly help you diagnose your problem and determine the best solution. Don’t let a little problem turn into something much bigger. Send us a message to start a conversation today.

I’d be an idiot if I did not take this opportunity to communicate to you how much we appreciate the way in which you conduct business and take care of our facility. In my experience you, and your team, are at the top of the list of all the roofing companies I’ve dealt with over the years. Thank you!

Jim Lowry - Bissinger's Handcrafted Chocolatier

Eric and crew were really nice to have around. They were courteous, careful and caused little if any disruption. Their work looks good too! To be honest… a good experience with a product that I initially had misgivings about. I’m a convert because of Bubba, Sam and Eric. Thank you.

Jim Lowry - Bissinger's Handcrafted Chocolatier

“I want to thank the crew at R&A for a job well done on our very leaky roof at the shop. It is certainly nice to have the drips and rivers gone from the shop when it is raining. I also wanted you to know how much we appreciated that the guys were able to stay out of our way and allowed us to do business as usual without any problems or interruptions. The roof looks great and the clean-up after the job made it so we couldn’t even tell you’d been here. Thanks for doing what you do so well!”

Jay Moore, President of Safe Way Tire and Auto Center

“My wife and I were on vacation when water pipes burst in our house. We got a hold of Craig and the R&A crew was able to start evacuating the water immediately. The best part was that they were able to start work before we even returned home. It was a very fast turnaround considering the extensive amount of water damage.”

Will from Dardenne Prairie, MO

“Craig and Mike came out in a timely fashion when we needed the work done. They did a reliable and quality job.”

Jerry from SLR Properties

“Craig helped us out tremendously with the insurance process. Timely and very professional.”

Lindell from Greater Missouri Builders (GMB)

“We purchased a house and there was some damage to the roof. Very impressed with the thoroughness of Mike’s inspection. Very comfortable with their explanation of what needed to be fixed. Most impressive was the way they protected our landscaping. Really liked the way they treated me as a valued customer, even though it was only a small project.”

Ross from Troy, MO

“I use R&A Contracting when my commercial roofs receive storm damage. They work on our behalf through every step of the insurance claim process. They perform all of the work and complete the insurance process, making our roofs better than they were before the storm.”

Director of Facilities for a large Property Management Company

“The team at R & A Contracting responded immediately when notified of our water disaster. They removed water-damaged materials and property quickly and restored our home even before the final settlement from our insurance company. They minimized how long our family had to live in a hotel and got us back to normal as fast as possible.”

Will from O'Fallon, MO