# Attic fan with both thermostat and humidistat



## Jackofall1 (Dec 5, 2010)

Hello and welcome dhcernese, to the best darn DIY'r site on the web.

I am sure the fan is no longer available with the humidistat switch as it has been determined that this is not really necessary, at least this would be my guess to why it is no longer offered.

Fan driven by temperature alone would do the job.

Mark


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## dhcernese (Mar 29, 2011)

*I require humidity removal in the winter*

Actually no. Speaking to GAF, the local sales rep claims the humidistat was removed because customers in the South had it set so that it ran so often the motor would fail within the warranty period.. lame reason.

Anyway, I absolutely require an exhaust fan in my attic during the winter because I just spent > $10K on mold remediation in the Northern walls. The primary driver is to remove humidity. 

My fall back is to completely replace the thermostat but I'd like to keep it to save on A/C costs in the summer.

Thanks,
Dan


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## Jackofall1 (Dec 5, 2010)

As you refer to, "Customers in the south" I take it you are in the north?

Adding a fan to remove damp air from an attic in the winter time should not be the final fix. You need to air seal all penetrations to the attic, ensure bathroom vents to the outside. 

You also need to ensure that the soffit vents are open and funtional, as well as either a ridge vent system or mushroom vents, the cause of the mold has got to be air escaping from the conditioned space into the attic, find the escaping air and ensure proper venting and your problem will be fixed, adding a fan is not the fix.

Mark


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## dhcernese (Mar 29, 2011)

Jackofall1 said:


> As you refer to, "Customers in the south" I take it you are in the north?
> 
> Adding a fan to remove damp air from an attic in the winter time should not be the final fix. You need to air seal all penetrations to the attic, ensure bathroom vents to the outside.
> 
> ...


Thank you for your advice, yes we're in New England. I'm not going into all the conditions and work that was done is part of the remediation. It included the soffit vent work (they are now as physically large as possible), new proper channels and in fact the mold removal warranty requires that we close the ridge vent if we have the attic fan. We have the fan after consulting a ventilation specialist. His opinion is that the fan would move more air in our cape-style structure than passive air movement would ever achieve. We discussed all the combinations of new ridge vent, gable vents, etc.

None of the people we've had inspecting before during or after identified any obvious route for bathroom or other moisture.


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## diyorpay (Sep 21, 2010)

I have same desire to have both a thermostat and humidistat control for attic fans. I used to rewire/jump seasonally, temp for summer, humidity for winter. 

I got sick of it so I wired a switch box into upstairs hallway with a 24 hour Intermatic timer switch. It takes seasonal resetting by logic but now I don't have to rewire all the time. I have 2 roof fans being controlled. The plastic box that forms the contained switch back is installed in a metal electrical box with no other devices on the same 20 amp circuit. It gets a little warm but no more so than a dimmer switch in dining room.
:thumbsup:


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## dhcernese (Mar 29, 2011)

diyorpay said:


> I have same desire to have both a thermostat and humidistat control for attic fans. I used to rewire/jump seasonally, temp for summer, humidity for winter. :thumbsup:


There's this https://www.greenair.com/browse/ct-dh-series.html but it has plug sockets not direct wiring.

I already have a thermostat and a Johnson control W43A, I want to design proper wiring for them (and if I need a relay I'll figure that out too)


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## AHaak (Jan 19, 2012)

*Attic moisture issue*

Hi guys, (from Pittsburgh, PA ...northern climate)

I've been retrofitting homes with high performing insulation solutions for several years now. I'm BPI and RESNET credentialed so have learned to analyze homes as systems. I've seen many moldy attics, and most of the time the culprit has been one or several bathroom fans vented into the attic rather than outdoors. 

However, during the past year I saw a number of attics that had very damp and moldy roof decking---but properly vented bathroom fans. In a recent case we air-sealed the attic deck with foam, confirmed the bathroom fans had been vented correctly, and then tested the tightness of the attic deck with a blower door---and it was tight. There was little if any moisture coming from inside the home, yet the roof decking was still saturated. It had to be coming from outside. When we checked the shingles they were spider-webbed with deep cracks all over them. 

I also worked in another attic this past summer with a major mold issue. The bathroom fans were not the issue. The homeowner (a single, elderly male) had the roof inspected and it was found that the original roofer had not used felt paper and that the shingles were themselves in bad shape. 

Both these roofs were relatively low sloping and had obvious shingle wear / lack of felt paper. Both homes were inhabited by 1-2 people--ie not a family of 7 taking 12 showers a day and thus putting lots of moisture into the air. The point is that even though the majority of my experiences have indicated that the moisture in the attic was coming from inside the home, that in these cases it was actually seeping in through the shingles. The worst areas were also the north facing sections of roof. So if you've accounted for the obvious moisture sources coming from inside the home, check the condition of the roof. :thumbsup:


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## Cvolpe (Mar 15, 2012)

I have some of the same issues mentioned above. Moldy roof decking. Bathroom fans seem to be fine but they do vent through the soffit and I don't like that. Have been plugging penetrations as I find them. I just put a new 50 year roof on 5 years ago. Before that the original roof was laid on the house (built in 93) with no felt. There was a little mold then but has recently exploded. I'm about to spend 11K to remediate. I did add soffit vents this past summer and had ridge vents put in when the roof was done but its a hip roof no not a lot of linear footage. Also have 3 passive vents in the roof facing the back of the house. I was going to add a fan with thermostat and humidistat. Don't know what welse I can possibly do!!!!!!


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## Chewbacka (Feb 27, 2014)

Hi, first post here. I know this is an old thread but I was wondering if the OP or others who posted found solutions to the issues of the roof deck moisture, temp/humidity, etc. I may have some answers if anyone's interested in continuing the discussion.

Chewy


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## Cvolpe (Mar 15, 2012)

figure I'd update for everyone. Had the remediation done. All the old insulation was removed from the attic. The whole attic was air sealed, I mean every nook and cranny. The vented the bathroom fans through the roof. I went around and made sure all the AC ductwork was sealed to prevent any air leakage from the registers (and wasting AC cooling the attic in the summer). I installed soffit vents all around and put in an attic fan (with thermostat and humidistat) where one of the passive vents(I have 3) were. Blew in new insulation. Added a wireless temperature and humidity meter to monitor the conditions in the attic. In the summer the humidity was like 15% so I thought I was good. However this winter the humidity was never below 90% and when I go up there there is condensation on the sheathing and the insulation feels damp. The humidity in the house in the winter is like 45-50% and outside it's in the 20% on clear dry cold days. How the hell can the humidity be 90% up there. Honestly I have just given up. don't know what else to do. By the way I went around after they blew in the insulation to make sure all the soffit vents were clear. I've been to other forums and they have filled my ear with relative vs absolute humidity which is all nice high school science but bottom line is that I still have moisture in my attic and I can't figure out where the it is coming from!


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## Jackofall1 (Dec 5, 2010)

Tvolpe said:


> figure I'd update for everyone. Had the remediation done. All the old insulation was removed from the attic. The whole attic was air sealed, I mean every nook and cranny. The vented the bathroom fans through the roof. I went around and made sure all the AC ductwork was sealed to prevent any air leakage from the registers (and wasting AC cooling the attic in the summer). I installed soffit vents all around and put in an attic fan (with thermostat and humidistat) where one of the passive vents(I have 3) were. Blew in new insulation. Added a wireless temperature and humidity meter to monitor the conditions in the attic. In the summer the humidity was like 15% so I thought I was good. However this winter the humidity was never below 90% and when I go up there there is condensation on the sheathing and the insulation feels damp. The humidity in the house in the winter is like 45-50% and outside it's in the 20% on clear dry cold days. How the hell can the humidity be 90% up there. Honestly I have just given up. don't know what else to do. By the way I went around after they blew in the insulation to make sure all the soffit vents were clear. I've been to other forums and they have filled my ear with relative vs absolute humidity which is all nice high school science but bottom line is that I still have moisture in my attic and I can't figure out where the it is coming from!


I take it you have a humidifier? If you do have a humidifier shut it down and continue to monitor the RH in the attic.


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## Cvolpe (Mar 15, 2012)

Nope no humidifier. I was actually desperate enough to think about putting a dehumidifier in the attic


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## Jackofall1 (Dec 5, 2010)

Tvolpe said:


> Nope no humidifier. I was actually desperate enough to think about putting a dehumidifier in the attic


Where do you live that may help determine some relative information related to ambient conditions.


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## Cvolpe (Mar 15, 2012)

Boston area


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## Jackofall1 (Dec 5, 2010)

Tvolpe said:


> Boston area


You have quite the conondrum going on there, but if I were to say anything it would be, you have to move more air through your attic. It appears that the mean line RH for the winter months in the Boston area is around 62%, which would indicate that during some days the ambient RH reaches >70%, in the evening as the temperature drops I would say you are condensing on the underside of your roof sheeting. 

Mark


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## Cvolpe (Mar 15, 2012)

Oh it's condensing all right. Never had this problem when I lived in CT, which isn't that far away from here. But there I had a ranch with gable vents on the sides. This current house has a hip rook which I've grown to hate. By the way 6 years ago we had a new roof put on. The original roof had no underlayment so they put the ice dam three feet up all around, installed a ridge vent on what little ridge is there and put underlayment down before putting down a 50 year architectural roof shingle. looks beautiful but has done nothing to help with the problem. So now for ventilation I have 2 passive roof vents, one roof fan and a rindge vents with about 100 soffit vents all around the perimeter.


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## Chewbacka (Feb 27, 2014)

Jackofall1 said:


> You have quite the conondrum going on there, but if I were to say anything it would be, you have to move more air through your attic. It appears that the mean line RH for the winter months in the Boston area is around 62%, which would indicate that during some days the ambient RH reaches >70%, in the evening as the temperature drops I would say you are condensing on the underside of your roof sheeting.
> 
> Mark


I agree that could be part of the problem. What I'd like to see is more details so we can help solve your mystery. How about what brand and model humidistat and temp sensors and size and brand of fan and CFM of same along with cubic feet of the attic area, direction of attic roof exposure, and gable ends. What altitude are you at? High on Beacon Hill, or down in the back bay? Thanks!:thumbsup:
Side note: I found this thread on Google while searching for a remote controlled humidistat and temp sensor to control an attic fan for the very same reasons you are trying to solve. I'm in process of doing so now, just ordered the controls from the link you provided in this thread earlier. So maybe we can help each other find solutions. I'm confident both our issues are resolvable; it's just a question of the right method/approach....

BTW, have you had an energy audit/analysis done prior to the remediation new insulation being added? If so, what does it show as to tightness, number of air exchanges, air exfiltration into the attic space, etc?

Chewy


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## Chewbacka (Feb 27, 2014)

Ok, you posted before I did so you answered what kind of roof you have, hip type. Like this ?: http://www.carpentry-pro-framer.com/images/parts-of-a-hip-roof.gif
If so, do you, or could you add gable end 'type' vents to the two ends of the shorter roof sections to allow more crossflow ventilation via the fan and ridge vent?


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## Jackofall1 (Dec 5, 2010)

Chewbacka said:


> Ok, you posted before I did so you answered what kind of roof you have, hip type. Like this ?: http://www.carpentry-pro-framer.com/images/parts-of-a-hip-roof.gif
> If so, do you, or could you add gable end 'type' vents to the two ends of the shorter roof sections to allow more crossflow ventilation via the fan and ridge vent?


Gables on a hip roof, I'm confused, unless you are suggesting building a dormer.

I am sure you have seen this, but just in case you haven't

http://www.buildingscience.com/documents/digests/bsd-102-understanding-attic-ventilation

Mark


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## Cvolpe (Mar 15, 2012)

I haven't seen that article. Looks very interesting. I read it quickly and printed it out so I can study it in more detail. I was wondering if it would make sense to just insulate the roof deck to prevent the roof sheathing from being a condensing surface as the article calls it. If I do that what happens to the soffit, ridge, passive and fan vents. Do they become useless?
I'll get al that other information this weekend to share. We did have an engery audit done as part of the remediation. I have to find the paperwork.


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## Jackofall1 (Dec 5, 2010)

I know you said you sealed up your unit and the attic, did you add vapor retarder? moisture readily passes through sheet rock. 

It still sounds like you don't have enough air moment in the attic. I believe the rule of thumb for vent space is 1 sqft of vent for every 300 ft3 of attic space.


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## Cvolpe (Mar 15, 2012)

You know the sheetrock wasn't seal except for any overspray when they sealed the sheathing after the mold remediation. It would suck to do it now with all the blown in insulation.


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## Jackofall1 (Dec 5, 2010)

Tvolpe said:


> You know the sheetrock wasn't seal except for any overspray when they sealed the sheathing after the mold remediation. It would suck to do it now with all the blown in insulation.


If there is not barrier there is a real good possibility that your moisture is coming through the sheet rock into the attic, but I am by no means an expert and you are correct it would be a tough this to do now that you have blown in insulation.


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## Chewbacka (Feb 27, 2014)

Jackofall1 said:


> Gables on a hip roof, I'm confused, unless you are suggesting building a dormer.
> 
> No, I'm not suggesting building dormers on the hip short roof sections; that's why I put the type vents in single quotes- sorry, guess I wasn't clear about what I was asking.
> 
> ...


Good article, thanks, but somewhat dated research/data. Here's a link that I found on the same site to a discussion about venting or not venting that I feel is very informative and particularly well suited to this thread's current discussion/dilema. :
http://www.buildingscience.com/documents/published-articles/pa-crash-course-in-roof-venting



Tvolpe said:


> I haven't seen that article. Looks very interesting. I read it quickly and printed it out so I can study it in more detail. I was wondering if it would make sense to just insulate the roof deck to prevent the roof sheathing from being a condensing surface as the article calls it. If I do that what happens to the soffit, ridge, passive and fan vents. Do they become useless?
> I'll get al that other information this weekend to share. We did have an engery audit done as part of the remediation. I have to find the paperwork.


Please, for all our sake, don't change anything right now until we have had a chance to interpret what exactly you have done to date, what may be working or close to working, and what changes might have to be done to accomplish what you seek as a final result. Remember, I'm in the beginning stages of doing what you've done but with a slightly different set of circumstances unique to my particular 'environment'.
BTW, gypsum board is an air barrier, but may allow some moisture through to your attic space- more about that later...
Your existing ventilation system, coupled with what may be missing in your approach may be what ends up being your eventual solution to the overall problem, hopefully.



Tvolpe said:


> You know the sheetrock wasn't seal except for any overspray when they sealed the sheathing after the mold remediation. It would suck to do it now with all the blown in insulation.


Here's how the link I gave above struck me initially. Paraphrasing: To seal an attic space one must first *completely* seal the ceiling area, BEFORE adding any insulation to the attic. Any migration/exfiltration of the below attic air/moisture MUST be stopped, first. No penetrations, can lights, pipes, bookshelves at ceiling height, etc. can interfere with the thermal barrier between the attic and living space.
This supports what Jackofall1 thumbsup said about moisture penetrating sheetrock and the amount of air movement you are creating. AND, it occurs to me if you, or I, have air leaks or moisture laden air leaks penetrating through to the attic space with out using mechanical means to draw air through and out of the cold attic area, then when we add air movement we are essentially also adding more migration of heated air/moisture OUT of the living space and INTO the attic uninsulated space, thus exacerbating the very problem we are trying to alleviate! {This seems to be where you are at now, and adding spray foam to the roof decking will NOT solve your problem in any way shape or form}. Therefore, both our issues may be resolved by making as close to 100% impenetrable sealing of the house ceiling below the attic, and then using the fan to move moist air or summertime hot air out of the attic as needed. How you ask? Possibly 'flash and batt'. Consider that if you were to solid cell spray foam 2-3" to the top of the attic ceiling area, (assuming you have open attic floor joists), then add back your blown over cellulose or whatever you have already installed, to create at least an R49 in the attic ceiling area with NO air/moisture passing through to the area from below, your attic moisture issue could then be controlled as necessary via your fan setup. Phew! Sorry for long description, but I think I'm onto what it will take to resolve your issues, But we still need your historical data and maybe some pics of the entire project to date?!


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## Cvolpe (Mar 15, 2012)

I'm still collecting that remediation data to post but your gonna have a hard time convincing me I'm pushing that much humiditiy through the sheetrock, especially since my ceilings have several layers of paint on them. I'm thinking the best bet it to get through it the AC registers which are in every room. i see that the snow takes a really long time to melt off the roof. My house is always one of the last houses to have snow on the roof, which is good since it means that I'm not melting the snow with my very expensive heating oil. That being said when I had almost a foot of snow on the roof the temperature in the attic was registering 36 degrees even when it was in the teens outside so is that snow insulating the attic?


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## Chewbacka (Feb 27, 2014)

The snow does act as an insulator; and the air in your attic is not benefiting from the passive solar gain the air outside sees.
Where is the central air system located, basement or attic? Do the ducts pass into the attic space? If so, then they are ceiling penetrations which could and likely do allow warm air to migrate into the attic. Are any ducts in the attic insulated and sealed with duct mastic and tape and an insulating blanket?


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## Cvolpe (Mar 15, 2012)

The AC unit is in the attic as are all the ducts. The ducts are flexible and insulated. Most of them are buried in the blown in insulation. While the registers can certainly leak air around the perimeter they were all sealed with foam when the rest of the attic was.


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## Chewbacka (Feb 27, 2014)

Tvolpe said:


> The AC unit is in the attic as are all the ducts. The ducts are flexible and insulated. Most of them are buried in the blown in insulation. While the registers can certainly leak air around the perimeter they were all sealed with foam when the rest of the attic was.


Have you had a chance to read the Fine Homebuilding article addressing 'to vent or not to vent', from the link I sent?
The article, IMHO, gives lots of good advice, including to not install AC or other air handlers in the attic, UNLESS one is doing a hot roof, i.e. a spray foam or similar on the roof deck to reduce the load on the AC in summer, and sweating/condensation in general.
This may end up being the ultimate solution to your issues, but again, let's wait until you present more data about what has been done to date.


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## SeanStrong (Jun 16, 2015)

*Anymore details or outcome to your attic moisture issue?*



Tvolpe said:


> I'm still collecting that remediation data to post but your gonna have a hard time convincing me I'm pushing that much humiditiy through the sheetrock, especially since my ceilings have several layers of paint on them. I'm thinking the best bet it to get through it the AC registers which are in every room. i see that the snow takes a really long time to melt off the roof. My house is always one of the last houses to have snow on the roof, which is good since it means that I'm not melting the snow with my very expensive heating oil. That being said when I had almost a foot of snow on the roof the temperature in the attic was registering 36 degrees even when it was in the teens outside so is that snow insulating the attic?


Hello Tvolpe,
I've got the same hip roof and problems you've described. Since I'm a contractor, of course the most I've done is clear the soffitt vents and add many more vents. I added much more blown insulation to what was already there from the 50-70's. I did have several bath vents that were rough and a huge chase that brought all the basement heat straight up to the attic.
My conclusion for the moisture in the attic was this after the past winter nightmare we endured. The moisture used the chase year after year to come into the attic! I blocked it from below with insulation but not quite enough.
My basement had always had moisture issues, I literally had a canning room with 4-6" of water in it year round. The neighbor has the same house built in the same year, and she's been there for 75 years. She told me that it was planned. The existing sump pump would keep the water from coming into the main area but the room had been designed to remain cool for the canning. This I get! But the moisture from this room made the entire basement a hazard zone for me and my allergies to mold.
I immediately dug a new hole and sunk a second pump in that room. Never to have a wet basement since. Except when the power went out and the pumps stopped working. Solved this with a genny! It wasn't until the 3rd winter with Ice Dams that I investigated the attic again. Thats when I saw the green/black funky patina covering all the roof decking inside and all the rafters as well. I immediately put the dehumidifier up there with a hose down the chase to the sump pump and left it run for the entire winter and into the summer. It dried up all the moisture that summer and I felt it was caused by the issue with the ice dams. I added a truckload of blown to what was there and never went up there again. That was 7 years ago. Every year since I had minimal ice dams but no water in the home. Last summer when I went up to replace some bath vents, I asked my electrician to change the wiring for as many of the switches and fixtures as he could along with the fans. When he was done I never had a chance to get up there and see his work because everything I wanted done was working, great, no problems. Wrong. He had gone up with a snow shovel and made 3-4' paths through all the insulation and completely uncovered the chase to run the wires. Exposing over 80+ sq.ft. of my ceilings in the process. On or around the 3rd storm this past year, by the way I snow plow too, I came home for a break at midnight and noticed the back wall of the house was covered in 4-5" of solid ice from the soffitts to the ground. The roof line had 2-3' of ice dams and even after shoveling them off I could stand up there with a 5' platform of ice on my 4'pitch hip roof. Still wearing my full snow gear I climbed into the attic and found water coming in from the soffitts to 7 or 8' up the roof. 
I found the shovel he used up there and spent 3 hours putting it all back. I had to wrap all the fixtures he installed with a foil bubble insul wrap I use to prevent the heat loss as well. Before I could cover them up with the cellulose. And me covered in sweat and cellulose in my snow gear. :furious:
The key thing I noticed was the chase. It was pumping a plume of moldy smelling warm air right up from the basement. I put back the plywood cover I had installed years before, covered that with insul and went to the basement. The water was pouring down the sides of my foundation from the walls and had partially flooded the floor. It was then that I realized that more than likely the water and moisture that had been in the attic all the years prior must've been coming up through the chase. From the canning room. All this and I'm now reading that the moisture could've been coming through the ceilings as well. Very discouraging! 
So, I am planning on one more finally assault to reclaim my roof attic and basement all in one key move. I could really use anymore thoughts on this from your experience before I make my final decision and go for it. 
I'm actually contemplating tearing off the entire roof and just going up one more floor, changing the roof to a gable and forget about it. I'm afraid I'm just not ready that phase this year, but I don't want to just do nothing.
Well, thanks for reading this if you've made it this far. I did send a note to you. So Maybe, you'll hear or see something in this that I've gone snowblind too. 
And I won't feel like banging my head again! :bangin:
Best regards, Sean


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## Cvolpe (Mar 15, 2012)

Wow, I thought I had issues. I feel for you!

Well my attic fan that i installed seemed to have died but I didn't think it was doing anything anyway. As soon as the temperature in the attic starts dropping the humidity starts soaring. In the winter when the temperature up there is below 40 the humidity regiasters at 90+. Then when spring hits and a nice sunny day occurs the temperature in the attic rockets up to 100 and the humidity drops to the 30s and 20s. This winter I did have 3 feet of snow on the roof for a long long time but did get ice dams from snow melting around my bathroom vents. My kids take like 1 hour showers so all that warm moist air ($$$$$) going out the vents melts the snow in the immediate area and it drips down and refreezes in the gutters. This summer I'm installing heat tape at the gutters. As I said in earlier posts when I had the mold remediation done I had every crack, hole and cranny caulked so warm air can't get into the attic from the house. The only access I can think about is the AC registers and returns. I think this coming winter I'm going to put a dehumidifier up there as I am out of ideas. Just cant seem to get enough ventilation into that attic. Best of luck with your situation. wish I had advice for you. Any way you can just plug up that chase entirely?


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## HDS (Jun 21, 2014)

Tvolpe, have you had your duct work blower tested? Also, a blower door test/energy audit to find leaks?

Sent from my SM-G900V using Tapatalk


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## SeanStrong (Jun 16, 2015)

Hi,
Thanks for the reply. 
I don't have any duct work in the attic space. Its all baseboard hot water.
Thats what makes me think the moisture comes from the basement.
Or from the heaters when the heat boils the water. The only thing I'm really unable to see is the chimney chase. I once thought that the heat in the chimney had moisture in it and when it hit the attic it cooled and condensated.
Over the years though .
I've actually had a couple of other plans for the moisture and the roof. Have you ever heard of or seen a cold roof system? One of my friends/customers 5-6 years ago, had my do a cold roof for them and it has changed everything. Although you don't have to, i removed the roofing down to the roof sheathing an covered it with 100% Roofers choice breathable roof membrane. I then put 2x4 cleats on top of every rafter and a layer of 5/8 plywood. Then I put on 100% Ice and water shield and roofed it. It was a long thought and planning process and even with all the planning there was some on the spot decisions. I actually used vented drip edge, a choice of the customer, along with creating a secondary vented soffitt design that I lined with Cobra vent and or Screen as needed. On the ridge I used Cobra vent and that was it. Other than the new and larger PVC trim boards the house looked better. He has since told me that all the upstairs has been significantly cooler and he can now cool the entire house with one well placed A/C and a fan that helps push the cold air upstairs. In the winter he no longer has huge heating bills. All in all. the goals were met and exceeded. 

He then helped me with another home with a moisture problem and our solution was to put in the roof fan and wire the unit 2 ways with 2 switches. one that controls the thermostat and one for the humidistat. He only needs to shut one off and put the other on with the changing of the seasons. He suggested that for me too.

Lastly, the dehumidifier that i put up in the attic. I now have it on a switched outlet and I have kept it on for months now set at 20% humidity. I very rarely hear it come on. I'm certain that this winter it'll help. I have it drained down through the chase by a garden hose and directly into a drain in the basement. 
As for the chase. I made a 3/4" plywood cover for it and then covered that with 4 layers of foil backed 2" foam board used for wall insulation under vinyl siding. 
Its R-12 per layer. My new best friend! 
I use it for making pull down staircase covers "coffin lids" and making solid blocking in the soffitts when I need it. 

I then put the dehumidifier on top of the hatch to hold it down. I noticed when I was up there that when the basement door was closed, the hatch would jump up from the pressure of closing the door. I think that my attic is as airtight from the living area as I can get.

I was actually hoping you found some real cause of the moisture and a solid solution. If you have, let me know. Thanks.
My plans are to remove the roof and go up with another floor or 2, but no hip roofs for me. Closed cell foam insulation with a metal roof over it for a cold roof for ever.

Thanks again for your reply.
Sean


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## Cvolpe (Mar 15, 2012)

So an update for everyone. Ended up doing the mold remediation AGAIN. The bathroom fan vents installed by Mass. Save who reinsulated my attic after the first mold remediation disconnected due to the fan vibration and damp shower air poured into my attic for months, making the mold come back with a vengence. So once again the insurance covered it and Serv Pro came in again to remove all the blown in insulation, blast the mold off, vacuum everything up and seal the sheathing and rafters with a mildew resistant sealer. This time I went up there and screwed the damm vents into the sheathing so they can't fall off and then caulked them do absolutely no air leakage. I'm going back to the batt insulation. Looked into the spray foam but too expensive. I'm going to lay down a vapor barrier first, reseal all the AC ducts and connections, box out the light fixtures and then lay down the batts and then maybe even put some plywood down so I can walk up there without falling through the ceiling (which the mold removal guys did 3 times). This attic is like my own Amityville horror story.


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## Cvolpe (Mar 15, 2012)

Alright I think I got this F*** thing figured out. After the second mold incident and remediation I decided if you want something done right you have to do it yourself. Using MASS Save was cheap but a disaster. After all the blown in insulation was removed (I hate that stuff) and the attic mold removed for the second time and the roof sheathing and rafters sealed I took the rest of the insurance money, bought 5 mil plastic sheathing and R30 unfaced batt insulation. I laid the sheathing down over the whole attic, which believe me was a PIA with the central air unit up there. Then laid down my batt insulation, making sure it didn't block the soffit vents. Since I miscalculated and ordered way too much insulation I laid down a second layer perpendicular to the first layer, so R-60!! Now my humidity is reading between 30-40% with the cold weather. At this time last winter it was reading 90% as soon as the temperature dropped into the 20's and 30's. It is amazing to me what a difference the vapor barrier makes. A assumed some difference but from 90% to 30%? Holy crap. Anyway I am done with that friggin attic.:biggrin2:


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## Bud9051 (Nov 11, 2015)

An old thread, but a common topic. Actually, the improvement was due to air sealing which the complete plastic layer provided. Test have shown that very little moisture passes through the painted drywall but gallons are carried into the attic by way of air leaks. Regardless, your solution worked, congratulations.

Bud


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## Cvolpe (Mar 15, 2012)

Actually I had every nook and cranny sealed after the first remediation but it didn't seem to make a difference. At any rate I'm happy. time to move on with my life.


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