Controlling condensation on metal buildings

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.

WHAT IS CONDENSATION??? Inside warm air rises holding moisture, of course.

If the warm moist air hits colder metal, then the air temperature grows colder. That air change temperature is bad.

The reason: cold air cannot hold as much moisture as warm air. As a result, drips form on the metal of your metal roof.

The drips 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.

If someone knew nothing about condensation..he/she would recaulk the soda can because the water had to have leaked from inside the can. Condensation experts would place coasters under/around the can .

Tips for controlling condensation

Circulate air, and keep the fans on. The more the fans are on, the less condensation will appear because the moisture will be blown away.

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

If a woman is pregnant, then she is truly pregnant, not just a little bit pregnant

Not true with condensation. The drips that annoy one owner may not even be noticed by a different 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.

Written by owner Miriam Cunningham