# Styrofoam vs. Plastic vent channels



## dpreznik (Oct 13, 2006)

Dear experts,

As I have already written before, I have condensation problem in my insulated attic. The water condenses during winter time on the plastic vent channel under the insulation. I added both ridge and soffit vents, but that didn't solve the problem. Now my question is: would it help if I replaced plastic vents with styrofoam ones? Maybe that would let the vapor go through the styrofoam and be carried away with the air flow between soffit and ridge vents?
Thanks,
Dmitriy


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## Clutchcargo (Mar 31, 2007)

The warm moist air is coming from the living area. If you can seal off a little tighter, I think your problem would be solved.


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## dpreznik (Oct 13, 2006)

Clutchcargo said:


> The warm moist air is coming from the living area. If you can seal off a little tighter, I think your problem would be solved.


But still there is a chance that some moist will get there. Would styrofoam vent channels instead of plastic ones help in this case?


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## Clutchcargo (Mar 31, 2007)

The moisture is going to condense on something. Styrofoam vs. plastic shouldn't make much of a difference, moisture won't go through the styro. Could you describe yor attic? You've really got to figure out where the leaks are and address that. Post some pictures if you can.


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## dpreznik (Oct 13, 2006)

Clutchcargo said:


> The moisture is going to condense on something. Styrofoam vs. plastic shouldn't make much of a difference, moisture won't go through the styro. Could you describe yor attic? You've really got to figure out where the leaks are and address that. Post some pictures if you can.


I shared with my problem here
http://www.diychatroom.com/showthread.php?t=6184
Briefly, I insulated my attic. Between the insulation and the roof, I have plastic vent channels. Also, I installed sheetrock knee walls and ceiling to turn the attic into a room. I still can access part of the insulation in the little space behind the knee wall. BTW, I have insulation on the whole roof up to bottom, not on the knee wall. When it was cold in the winter, I noticed water dripping from the insulation. That place was right above the two my bathrooms. The farther from that place, the less water was there in the insulation, but some water was everywhere at least on the plastic vent channels. Both bathrooms have exhaust fans, but I guess they were not enough. I added ridge vent, but it didn't solve the problem. Also, I have no idea if there is any moisture above the sheetrock of the ceiling.
I thought about removing the paper from the insulation I can reach and replacing it with plastic vapor barrier, but I am afraid that in case if some moist gets there anyway, there will be no way for it to dry up.
I would appreciate any advices.


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## Clutchcargo (Mar 31, 2007)

Where does the bathroom vent to? I'm sorry if these are elementary questions, but the fact that moisture is moreso around the bathrooms is a significant clue.


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## dpreznik (Oct 13, 2006)

Clutchcargo said:


> Where does the bathroom vent to? I'm sorry if these are elementary questions, but the fact that moisture is moreso around the bathrooms is a significant clue.


I understand that it is important. But the moist goes outside. In one of the bathrooms, the fan is over the toilet bowl instead of the bath tub / shower, so it takes longer for the moist to reach the fan... Maybe that adds to the problem...


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## Clutchcargo (Mar 31, 2007)

How old are those units? Is there a possibility that the air vent lines are cracked, loose, etc.?


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## Ed the Roofer (Jan 27, 2007)

Is the soffit ventilation 100 % continuous and provides at least the bare minimum of 9 square inches per lineal foot on each side of the house?

If you are un-balanced, the air flow may not be getting flushed through and is being stifled in the baffle vent chambers.

What system or scenario do you have to create the 100 % continuous soffit fresh air intake ventilation system?

Are the ridge vent and soffit vent holes cut out to the manufacturers size specifications?

Ed


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## dpreznik (Oct 13, 2006)

Clutchcargo said:


> How old are those units? Is there a possibility that the air vent lines are cracked, loose, etc.?


The exhaust fan in the bathroom we were using during the winter was old. I installed the pipe myself, so I don't think it is cracked, but I am not sure the connection is airproof.


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## dpreznik (Oct 13, 2006)

Ed the Roofer said:


> Is the soffit ventilation 100 % continuous and provides at least the bare minimum of 9 square inches per lineal foot on each side of the house?


Yes, the soffit ventilation is 100% continuous, I cut openings against every rafter bay.


Ed the Roofer said:


> If you are un-balanced, the air flow may not be getting flushed through and is being stifled in the baffle vent chambers.
> 
> What system or scenario do you have to create the 100 % continuous soffit fresh air intake ventilation system?
> 
> Are the ridge vent and soffit vent holes cut out to the manufacturers size specifications?


I don't know about the ridge vent, because I hired a guy to do the job. But to be honest, I don't understand how it could even help, because the plastic vent channel prevents the moisture to reach the air flow to get flushed, thus the water condenses on the opposite site of the plastic.


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## Ed the Roofer (Jan 27, 2007)

Is there a nearly 100 % sealed vapor barrier installed on the warm underside of the insulation?

Ed


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## dpreznik (Oct 13, 2006)

Ed the Roofer said:


> Is there a nearly 100 % sealed vapor barrier installed on the warm underside of the insulation?
> 
> Ed


It has only that paper which goes with the insulation. Last Summer, I tried to add plastic film vapor barrier, but the water started to accumulate between the paper and the film, so I removed the film. Maybe I had to rather remove the paper...


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## Ed the Roofer (Jan 27, 2007)

I don't think removing the kraft paper surfacing on the insulation will be the answer.

Do you have excessive humidity inside the home, such as many showers being taken, a significant number of plants inside being watered daily, or running a humidifier, or any other additional moisture creatore internally?

Have you tried running a De-Humidifier, to relieve the intern RH content of the home?

If that still leaves the humidity level to such a state continually causing this condensation, then you probably have a leak in one of the exhaust fan hoses pumping the moisture into the structure.

Sorry I could not be more definitive in your case so far.

Ed


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## dpreznik (Oct 13, 2006)

I meant not just removing the paper, but replacing it with the plastic film.
Thank you anyway. I appreciate your wish to help.


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