Condensation With a Metal Roof
It’s winter time (is it this year??) and you’re getting water dripping from your roof…..the roofer comes out and says it’s not leaking??? The roof isn’t even that old; so what exactly is going on? Well, if it’s a metal roof, it’s most likely condensation. In this blog, we are going to dive into why it’s happening and what are some ways your roofing company can make it stop and even some things you can do on your own to help with this. Let’s dive in!
What Causes Condensation on a Metal Roof?
To answer this, let’s first establish and explain how condensation even comes to be. Condensation forms when warm, moisture-laden air hits a cold surface. In the case of metal roofs, it happens when warm, moist air from inside the building comes in contact with the cold metal roof or cold air that gets in between the metal roof ribs and seams. Once those opposing temps meet, condensation occurs. You see this on your ice cold lemonade glass on a hot summer day! The same occurs in the summer time with a hot metal roof, and cooled air inside the building but at a much lesser rate because as we know heat rises so the cooled air doesn’t get to the roof in the summer as much as the warm air gets to the roof in the winter. And then you have water leaking from the roof, and it can be a lot!
How Can You Stop Your Metal Roof from Sweating?
Well first and foremost let’s talk about what you can do as the building owner. First you can call an HVAC energy management company or engineer to do a load analysis on the building and design a heating/cooling plan to minimize the effects of the inside temps on this condensation issue. They will also hopefully help to design a plan and system to maximize your energy dollars being spent. The other thing you can do is insulate the underside of the metal roof. The more you insulate the more those two opposing air temps can be kept away from each other. Now this isn’t always a possibility, as the access to the underside of the roof may not be there.
What Can My Roofer Do?
Once you have done all you can on the inside, it’s time to discuss what your roofer can do on the outside. With that, you have essentially two options….Spray Foam or a Single Ply Membrane Overlay System. Let’s discuss, shall we?
Spray Foam
Applying a Spray Foam system is a great option. It insulates the top side of the roof. It gets in all the gaps and seals them. And it stops the inside condensation issue in its tracks. The roof is cleaned, spray foam is applied, then the spray foam is coated. In our opinion, this is probably the best solution. For additional information, read “How Foam Roofing Can Enhance the Quality of Your Roof“
Single Ply Membrane
But a very very close second option is the Single Ply Membrane overlay system. In this system, sheets of insulation are put between the ribs of and over the entire metal roof. Creating a leveling of the roof. Then the Single Ply system is installed over the entire roof. This does the same thing as the spray foam system, it insulates the roof and seals (covers) the gaps where air was getting in. However this system is a little more costly as there is more labor and more materials. Also we feel spray foam being an expanding liquid so to speak just gets in those gaps and fills them rather than just covers them up. If you would like more information on Single Ply, check out our article “TPO vs Single Ply“.
What will not work?
One system that will not work to eradicate this issue is a standard coating system. While yes, our coating system starts with putting a kevlar fabric over all the seams and gaps, there is no insulating factor to a coating system leaving the bottom side of the metal still cold in the winter or hot in the summer. Also, changing the color of the roof white as we often do with a coating system, will make the issue worse especially in the winter
In Summary
It can feel like a gut punch having a newer metal roof leaking condensation down on you. It feels like the roof is nearly new, and I am already having issues!! But, the things we discussed above to take care of the issue, aren’t really fixing the roof. They are doing what should have been done in the first place. And once they are done, the roof will be complete and keep you dry and leak free for many years to come. And, will save you money on your utilities as well. If you have any additional questions regarding these issues, feel free to pick up the phone and call J Smucker Contracting!