Helpful? 0

How to stop a cathedral roof from sweating?

I have good venting but it still sweats ........

Asked by Gary Bleedorn
Posted Sat, 02/08/2014 - 19:14
Edited Sun, 02/09/2014 - 06:48

Tags:

1 Answer

Select your preferred way to display the comments and click "Save settings" to activate your changes.
1.
Helpful? 0

Gary,
The reason that condensation is accumulating in your cathedral ceiling assembly is that your ceiling is leaky. Warm, humid interior air is escaping through holes and cracks in your ceiling. When the humid air contacts a cold surface (usually, the underside of the roof sheathing), the moisture condenses (or, more accurately, is adsorbed by the sheathing, or in some cases accumulates as frost).

Ventilation can't solve this problem. In fact, ventilation can make this problem worse (by accelerating the flow of air through your ceiling cracks).

The solution is to include a ceiling-side air barrier (or to seal all of your ceiling leaks). For more information on these issues, see these two articles:

How to Build an Insulated Cathedral Ceiling

All About Attic Venting

Answered by Martin Holladay, GBA Advisor
Posted Sun, 02/09/2014 - 06:47
Edited Sun, 02/09/2014 - 15:53.

Other Questions in General questions

In Energy efficiency and durability | Asked by maggie wilbur | Apr 19, 14
In Mechanicals | Asked by Kent Jeffery | Apr 16, 14
In General questions | Asked by RobertBolf RobertBolf | Apr 20, 14
In Mechanicals | Asked by Peter L | Apr 19, 14
In Energy efficiency and durability | Asked by Erik Schmitt | Apr 19, 14
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!