# Water in the insulation



## dpreznik (Oct 13, 2006)

Could anybody help me in my problem?
Some time ago I finished my attic. I put plastic vent channels next to the roof, then put insulation (vapor barrier towards inside). Now with this cold weather, the whole insulation is soaked with water, and particularly next to the plastic vent channels (where it is most cold). I guess it is condensation. I have soffit vents and no ridge vent, but I guess during the winter it would not help anyway. Can anybody tell me what I can do?
Thanks,
Dmitriy Reznik


----------



## concretemasonry (Oct 10, 2006)

It appears you have no ventilation and any moisture can condense and accumulate.

Your soffit vents will not work unless you have vents near or on the ridge. - There is no way for the air to circulate, so the water wilcondense on any cold surface.


----------



## redline (Mar 5, 2006)

No ridge vent?
Do you have any other type of vent near the top of the roof?


----------



## dpreznik (Oct 13, 2006)

No, I have nothing at the top, only soffit vents.
But I wonder how cold air flow can help avoid condensation on the opposit side of the vent channel? We still have there warm air meeting the cold surface of the vent channel, don't we?


----------



## concretemasonry (Oct 10, 2006)

The top vent carries the moist air out of the venting area.

Where did you put your insulation? - Not against the roof I hope.

You MUST have an air flow under your roof sheathing to exhaust the moisture. I would also check for ways moisture could be getting into your attic. - Do you have a vapor barrier to keep the moisture inside the house?


----------



## dpreznik (Oct 13, 2006)

Thank you very much for the answer.



concretemasonry said:


> The top vent carries the moist air out of the venting area.


How is that? The air would go from the soffit vent through the vent channel to the ridge vent. The moisture is separated from the air flow by the plastic vent channel.


concretemasonry said:


> Where did you put your insulation? - Not against the roof I hope.


The insulation is against the vent channel which is against the roof. So there is a space between the roof and the insulation.


concretemasonry said:


> You MUST have an air flow under your roof sheathing to exhaust the moisture.


I just don't get how the moisture would be exhausted if it is separated from the air flow by the plastic of the vent channel.


concretemasonry said:


> I would also check for ways moisture could be getting into your attic. - Do you have a vapor barrier to keep the moisture inside the house?


Yes, I use insulation with vapor barrier paper on it, but it is not complete barrier, of course.


----------



## concretemasonry (Oct 10, 2006)

You said you have no ridge vent so there is no ventilation and circulation!!

Your soffit vents are doing nothing and the moisture is accumulating somewhere and is trapped in the fiberglass, which does a wonderful job of holding it.


----------



## dpreznik (Oct 13, 2006)

concretemasonry said:


> You said you have no ridge vent so there is no ventilation and circulation!!
> 
> Your soffit vents are doing nothing and the moisture is accumulating somewhere and is trapped in the fiberglass, which does a wonderful job of holding it.


 
But if even I had the ridge vent, how would the moisture penetrate through the plastic of the vent channels to get to the ridge vent?


----------



## concretemasonry (Oct 10, 2006)

The chutes are not meant to be vapor barriers. They are just a friction piece of foam or cardboard. Their purpose is to provide an open area for the ventilation from the soffit vents up through the ridge or roof vents. By not having roof vents, you are stopping ventilation.

You already recognize that the minimal vapor barriers on fiberglass or poly film is not perfect. You also have some leakage from your house upward through cracks and around your access hatch or doorway. The ventilation is to remove the warmer humid air rather that let it condense on a cool surface.

It is possible to insulate the underside of your roof, but I am sure you do not want that expense (unless you own or a promoting some kind of foam) and all the other sealing requirements.


----------



## dpreznik (Oct 13, 2006)

concretemasonry said:


> The chutes are not meant to be vapor barriers. They are just a friction piece of foam or cardboard. Their purpose is to provide an open area for the ventilation from the soffit vents up through the ridge or roof vents. By not having roof vents, you are stopping ventilation.


I understand that those things were not intended to be vapor barriers. But because in my case they are made of plastic, they actually are barriers. So I don't understand how would the moisture penetrate through it even if I had the ridge vent? Maybe it was wrong to install plastic vent channels?


----------



## concretemasonry (Oct 10, 2006)

Of course they might stop some vapor, but the are either stapled or friction fit with cracks. There is no seal and none is intended.

You violated the critical ventilation rule and do not have any roof vents and that is the major problem. Correct that and then see if there is anything else to address.

Post photos so we can see what other problems there might be.


----------



## dpreznik (Oct 13, 2006)

Thank you very much for your help.


----------



## redline (Mar 5, 2006)

Why was a ridge vent not installed after you went to the effort to put in the baffles?

Now you have to install the ridge vent, remove the wet insulation, replace the insulation and/or drywall...


----------



## dpreznik (Oct 13, 2006)

redline said:


> Why was a ridge vent not installed after you went to the effort to put in the baffles?
> 
> Now you have to install the ridge vent, remove the wet insulation, replace the insulation and/or drywall...


I didn't think it was necessary. Also, I did everything myself, and I would not be able to install ridge vent. I am afraid of heights.

Don't you think the wet insulation can dry up by inself if I install the ridge vent?


----------



## concretemasonry (Oct 10, 2006)

You will have to put in some kind of roof ventilation.

Your fiberglass will not dry out enough in place to perform efficiently. As little as 1/2 to 1% moisture can have an effect.

Fiberglass does not absorb moisture but it will hold water. Dues to insulating concept of "dead" air spaces, you will not get enough circulation to dry it out while it is in place. Since you should remove it, you would be better off to just replace with new, rather than try to COMPLETELY dry out the old.


----------



## AaronB (Jan 29, 2005)

You need to vent the attic (making the insulation useless) or install a de-humidifier, or remove the insulation and place new dry insulation on the ceiling.


----------



## AaronB (Jan 29, 2005)

With a monolithic vapor barrier, not a vapor retarder, which slows, but does not stop air infiltraion.

Look into SPF insulation...a complete air stop if installed correctly.


----------



## dpreznik (Oct 13, 2006)

AaronB said:


> You need to vent the attic (making the insulation useless) or install a de-humidifier, or remove the insulation and place new dry insulation on the ceiling.


Did you mean to install the dehumidifier temorarily, just to let the insulation to dry up?
I would prefer not to replace insulation or vapor barrier, because it would require to destroy all the walls and ceiling, and it would be a pity.


----------



## concretemasonry (Oct 10, 2006)

You will not dry out fiberglass with a dumidifier, no matter how long you use it. A dehumidifier is just that - it is not a dryer and does not have enough air flow or provide circulation. This is espeicially true if you have the wall finished or covered.

Even if you take out the insulation, you will be surprised what it takes to really remove the moisture. - Do you have a very long covered closeline with good circulation in an arid climate?

The longer you leave the wet insulation in the wall with wood and cellulose (if you have sheetrock), the better chance to get mold and rot. It happens faster in warm weather and a roof gets warm without ventilation.


----------



## AaronB (Jan 29, 2005)

I did not mean to use the de-humidifier to dry out the insulation.

If you cannot access the insulation, how do you know it's wet?


----------



## dpreznik (Oct 13, 2006)

AaronB said:


> I did not mean to use the de-humidifier to dry out the insulation.
> 
> If you cannot access the insulation, how do you know it's wet?


I can access it in a limited area, behind a knee wall. I have a door there. Behind that wall, the insulation is not covered with sheetrock.


----------



## AaronB (Jan 29, 2005)

Is this a Cape Cod?


----------



## dpreznik (Oct 13, 2006)

AaronB said:


> Is this a Cape Cod?


I am sorry, I don't understand the question.


----------



## redline (Mar 5, 2006)

dpreznik said:


> I am sorry, I don't understand the question.


I believe AaronB is asking what style of house do you have.
ie. Cape Code, colonial, ranch, victorian...


----------



## dpreznik (Oct 13, 2006)

redline said:


> I believe AaronB is asking what style of house do you have.
> ie. Cape Code, colonial, ranch, victorian...


It is a ranch. It has a cathedral ceiling over the living room, and stairs to an inside balcony over the living room. The balcony leads to the attic over bedrooms, which I turned into a new room.


----------



## AaronB (Jan 29, 2005)

If it is, indeed, condensation, instead of a roof leak, then you will probably need to add insulation in order to move the dew point to within the insulation assembly. Then, your warm moist air will not condense on the ceiling cuz there will not be a thermal differential. No cold surface, no condensate.

A de-humidifier to remove heater gas moisture would surely aid in your efforts. I think I would try this first, depending on your climate.


----------



## dpreznik (Oct 13, 2006)

AaronB said:


> If it is, indeed, condensation, instead of a roof leak, then you will probably need to add insulation in order to move the dew point to within the insulation assembly. Then, your warm moist air will not condense on the ceiling cuz there will not be a thermal differential. No cold surface, no condensate.


But I have no more space for additional insulation, I installed as much as possible. R49


AaronB said:


> A de-humidifier to remove heater gas moisture would surely aid in your efforts. I think I would try this first, depending on your climate.


Do you mean even before installing the ridge vent?
BTW, maybe you know about how much it may cost to install the ridge vent, if the roof is 47 feet long?
Thanks.


----------



## AaronB (Jan 29, 2005)

If it is happenening how you say it is, I do not think ridge vent will help the condensation problem, but your roof still needs underside venting. 

I would install a shingle-over ridge vent on a walkable ranch 47 feet long for approximately $900.00.

You would still be left with your air exfiltration problem. I think a vapor BARRIER would help immensely, but you would have to do either roof deconstruction, or interior deconstruction.


----------



## dpreznik (Oct 13, 2006)

AaronB said:


> If it is happenening how you say it is, I do not think ridge vent will help the condensation problem, but your roof still needs underside venting.
> ...
> You would still be left with your air exfiltration problem. I think a vapor BARRIER would help immensely, but you would have to do either roof deconstruction, or interior deconstruction.


I used to have vapor barrier, but in the spring, water was condensed between the barrier and retarder, so I removed it before even installing the sheetrock. I guess it would be better to remove the retarder, but now it is too late. I am in desperation.


----------



## AaronB (Jan 29, 2005)

Find the source of moisture infiltration and seal it off.


----------



## dpreznik (Oct 13, 2006)

AaronB said:


> Find the source of moisture infiltration and seal it off.


But isn't some water always in the air?


----------



## AaronB (Jan 29, 2005)

Sure there is, but ambient moisture is not what we are generally seeing that causes excessive condensation in heat differential conditions.


----------



## cibula11 (Jan 6, 2007)

If your roof is completely finished, installing ridge vent would NOT be the way to go. If you are planning on reroofing it, then definately go with ridge vent.


----------



## AaronB (Jan 29, 2005)

You can easily add a ridge vent, but still do not think it will solve your problem.


----------



## dpreznik (Oct 13, 2006)

If the ridge vent will not solve my problem, should I install it even if it can be done easily (by an expert)? Or what is the advantage of having it, if it will not solve my problem? Maybe it is better to wait until it is time to replace the roof?


----------



## BWB (Feb 2, 2007)

the biggest problem is probably the fact that you have insulation with the vapour paper on it, and not vapour barrier. The warm air is blasting right around the insulation - add to that the lack of ridge vents and voila.


----------



## dpreznik (Oct 13, 2006)

BWB said:


> the biggest problem is probably the fact that you have insulation with the vapour paper on it, and not vapour barrier. The warm air is blasting right around the insulation - add to that the lack of ridge vents and voila.


Yes, I understand that. I guess the problem is that my bathroom is right under that section of the house, though I do have exhaust fan there. Maybe I should start with painting the bathroom ceiling with some kind of special paint to prevent the moisture penetrating.


----------



## MoldBuster (Jan 18, 2007)

concretemasonry said:


> You will not dry out fiberglass with a dumidifier, no matter how long you use it. A dehumidifier is just that - it is not a dryer and does not have enough air flow or provide circulation. This is espeicially true if you have the wall finished or covered.


Depends on the dehu. Some have some pretty serious amounts of airflow. Some of the bigger dessicant units have up to 7000 cfm of airflow...probably adequate. I've dried out many fiberglass walls with our bigger dehumids (not the dinky little store bought ones...commercial restoration grade units. That being said...there are three things that are key to drying...

1) Heat. Most commercial dehumids work best between 80-90 degrees F. There are high temp versions that work up into the 110 degree range. 

2) Airflow. You need airflow to help release the water from the materials and vaporize it into the air for removal. 

3) Esposure. The more exposed the surface of the materials, the faster things will dry. It is possible to dry the inside of a sheetrocked insulated wall, but it takes massive amounts of BTU's and a boatload of airflow to do so. 

_The longer you leave the wet insulation in the wall with wood and cellulose (if you have sheetrock), the better chance to get mold and rot. It happens faster in warm weather and a roof gets warm without ventilation._

Absolutely 100% agreed. What I would do in this situation (attic) is to set up a drying furnace and pump a lot of CFM of hot,dry air up into the attic with some blowers to dry the space out. I'd lift the insulation up out of the bays and make sure there is airflow under the insulation as well as over it. 

Once dry, I'd install top vents PLUS an active vent fan (tied into a humidistat and thermostat) to get active airflow thru the attic (ridge vents are not always enough as my extensive experience in treating moldy attics with them proves). Last but not least, I'd install a bathroom vent fan. The only "special paint" that will stop mold from growing is a product called Mycodyne (which yes, for disclosure purposes, I do sell). This will NOT waterproof the walls...it will stop growth for a minimum of 25 years (guaranteed) but I would STILL install a bathroom fan.


----------



## dpreznik (Oct 13, 2006)

MoldBuster said:


> Once dry, I'd install top vents PLUS an active vent fan (tied into a humidistat and thermostat) to get active airflow thru the attic


The problem is that most of my attic is finished, and I don't even know what is above the sheetrock. The space which I can access is between the roof and the knee wall, so I don't think it would be a good idea to install a vent fan in that nerrow space. 
BTW, I did install the ridge vent, but it didn't solve the problem, and the insulation is still wet. I opened it to let it dry, but I am afraid, as soon as I put it back, the problem will appear again. I wonder why it had to happen to me, and not to most of the other people. Tough luck...


----------



## dpreznik (Oct 13, 2006)

BTW, can the condensation be worse because I used plastic instead of styrofoam vent channels?


----------

