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| NEW: Commercial metal roofs with exposed fasteners...why does condensation happen here. | Vintage tin roof owners...tips for metal roof condensation control |
Is it a leak....or condensation?
On a sunny day, an inside tennis player complains about the leaky roof. Sure enough, there are drips on the floor. How do you stop the "leaks."
Or you have paid a roofer a significant sum to repair some leaks that occurred on a rainy day. The roofer even returned when you called about the reoccurrence of the leaks. After several calls from you, the roofer has disappeared. At this point, you should consider condensation in metal buildings’ prevention.
In first grade language, warm air rises holding moisture. If the warm air hits colder metal, then the air temperature grows colder. That air change temperature is bad. The reason: colder air cannot hold as much moisture. Drips form on the metal...and grow heavy, then fall downward.
How is the problem fixed?
Whenever attempting to stop condensation, imagine a cold soft drink can in your vehicle located in your door pocket where vehicle's circulating air misses the can. Now imagine the same cold soft drink can in front of your AC vent on your dash. Which can will sweat less? And why? Of course you know the answer: the can in front of the AC vent on your dash because the air blows moisture away.
Now suppose you want to stop the water "leaking" problem of the can in the door pocket. Would you recaulk the soda can because the water "had to have leaked out"....or would you take other steps—such as placing coasters around/underneath.
Use the same approach with metal roof condensation problems.
Circulate air, and keep the fans on. The more the fans are on, the less condensation will appear.
Install roof vents to allow the warmer interior air to escape. Ridge vents are best.
Try dehumidifiers to remove moisture from the air. Even running the compressors of your AC units could help.
Check your lighting and heating devices. Some versions of these devices affect the air temperature less. An oil heater located just under a metal panel is guaranteed to generate condensation.
Consider vapor barrier work. The vapor barriers are the coasters around the soda can. Vapor barriers keep moist air away from metal surfaces. Even a small break in your vapor barrier could (under some circumstances) be an annoying drip.
Condensation: no single answer
Condensation is unlike a pregnancy. One is or is not pregnant. In contrast, condensation is relative. The annoying drips for one owner may bother another metal building landlord. For example,
1. An indoor roller skating rink must have a perfectly dry surface to skate on. One of my customers ran his air conditioner in November and December, just to keep the air dry enough to absorb the moisture collecting on his rafters
2. A tennis court owner decided the occasional drips were not worth the cost of repairing the vapor barrier. Indeed, no vapor barrier repair outfit can reasonably promise complete elimination of condensation without redoing the entire building. But a smart, handyman-type may be able to help.
3. A trucking company recognized that the new equipment and extra manpower increased the moisture too much, A simple roof vent improved the air circulation
As a long-time roofer in the field of preventing leaks on metal roofs, I have had to learn basic prevention of condensation on metal roofs. If I am in a building with damaged vapor barrier and no vents, I make sure the owner is comfortable with the role condensation may play. My trick question is, “Have you seen condensation on a rainy day?” If he/she says, “No, only roof leaks,” then I say, “Imagine a glass pitcher with ice on a porch…..”