# Interior vaulted ceiling sweating



## Mattio (Feb 28, 2016)

Hello,
I would appreciate some opinions on how to fix an issue with an enclosed vaulted ceiling that is producing excessive condensation on the interior at the ridge beam. 
The roof framing is 2x10 rafters with blocking. The bays are filled with R30 insulation and the rafters are enclosed with 1x6 tongue and groove for the interior ceiling. 
The bays are completely closed in with no sofits or vents on the exterior wall, and no means for the air to escape at the ridge.
The homeowner provided plans. (Please see attachment with photos).
I'm aware of differing opinions on whether the bays should be allowed to vent (difficult with blocking in the way) or should be completely sealed with sprayed insulation to where no air would pass.
If anyone would be willing to offer an opinion on what might fix the issue I would really appreciate it.
Thanks


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## kiteman (Apr 18, 2012)

*Interior Vaulted Ceiling Sweating*

I would have been required to leave a space above the blocks or notch them. 
Then cross-notched the rafters or used ridge vent. 

Sent from my iPhone using Tapatalk


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## Rio (Oct 13, 2009)

Is it leaking through the roof or condensing on the ceiling?


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## jlhaslip (Dec 31, 2009)

The cure for that is ventilation.
Probably easiest to do it from the top, so, rip the old roof off and furr out the rafters with 2 x 2's and re-sheath it. Ridge venting and Eave venting is required. 
As an alternate for the 2 x 2's, you could also cross strap the rafters with 1 x 4's and then add strapping again to allow for cross bay ventilation. We use that on metal roofs.
Sorry, but there is no easier way that I am aware of.


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## Mattio (Feb 28, 2016)

There doesn't appear to be any leaks from the outside. The roof itself is fairly new. It does seem to be condensation.

It does look like removing the roof would be the best option. I'm just concerned with this one as I want to be sure it will fix the problem.


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## greg24k (May 19, 2007)

Condensation on the ceiling indicates a combination of high humidity and a cool ceiling and most likely the ceiling cavity does not have adequate ventilation... You in South CA the heat build-up can easily make that ceiling sweat when there is no ventilation and given a good amount of humidity and moisture you got all the right ingredients to case that condition.


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## Rio (Oct 13, 2009)

If it's not leaking then as pointed out it's a combination of high relative humidity and a cool surface that it's condensing on. A possible fix without resorting to ripping off the roof and insulating it better might be to get a dehumidifier and run it along with increasing the air flow up by the ceiling, perhaps a ceiling fan or two?

We've done similar cathedral ceilings, non vented, in southern California without any problems. It's normally so warm and dry there's not a lot of moisture in the air and condensation on the ceiling hasn't been an issue.


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## ScipioAfricanus (Sep 13, 2008)

Another fix for this is to remove roof material and then add 2" of foam board to the roof deck then re-roof the thing.

Andy.


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## madmax718 (Dec 7, 2012)

This room next to a bathroom by any chance?


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## tipitop (Dec 3, 2013)

Did a couple of cathedral ceilings and always was required by city to do foam insulation in ceiling. It is not question at all. Never nobody call me back about ceiling sweating. It is not even question here in Mn. Cath c = foam.


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## Mattio (Feb 28, 2016)

I've heard two differing opinions on cathedral ceilings - whether to vent or whether to spray foam with no venting. TipiTop's response sounded promising if time tested. I'm still hesitant on taking the roof off to spray the cavities without being certain it will fix the problem.


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## tipitop (Dec 3, 2013)

Mattio said:


> I've heard two differing opinions on cathedral ceilings - whether to vent or whether to spray foam with no venting. TipiTop's response sounded promising if time tested. I'm still hesitant on taking the roof off to spray the cavities without being certain it will fix the problem.


That I can not help you bro. I know what is code here in mn. It is not something that I have right to think about at all.


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## Brad Gunn (Aug 18, 2015)

*Tipi's Back*

Wecome Back.:clap: Now I'm going to sign up.


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## red_cedar (Mar 30, 2005)

20yrs ago was on a home that had similar problems. It was a cathedral ceiling with tongue and groove wood ceiling on the inside. The outside assembly was actually framing with rigid foam as insulation. Cedar shingles was the roof covering. Besides my expressed concern, no ventilation was incorporated into the roof assembly per architect.
Nobody wanted to redo the roof. They ( builder) ended up reducing the moisture in the room and added some air circulation. Problem only showed up at certain times when cold outside.


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