1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
    Caluwe - Passion for Fire and Water ( Pellet and Wood Hydronic and Space Heating)

Humidifiers

Post in 'DIY and General non-hearth advice' started by BrotherBart, Feb 25, 2013.

  1. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

    Joined:
    Nov 18, 2005
    Messages:
    28,057
    Loc:
    Northern Virginia
    Just a for what it's worth post. Lots of posts here about humidifiers. After 27 years burning wood in this joint, last year I had a serious health hit and suspected the trigger was low humidity in the place, 20 percent when burning, and got a lot of relief by firing off several humidifiers and keeping the place around 40 percent during the heating season. Continued with it this year.

    Today i went up to check the flue and coming down I passed the gable vent and caught the distinctive smell of mold coming out of it. Went down and went up in the attic. Entire place covered in mold. Underside of sheathing and rafters. This ain't gonna be easy or cheap. I was up there just six months ago and it was not there.

    Only change in 27 years was the humidifiers. And I have spent a while on the web finding a lot of people that had the same thing happen with humidifiers. Yeah, it has to be getting up there somewhere but the heat going upstairs is carrying the humidity with it, which I was loving. But now to find how it gets in the attic.

    Just sayin, check those attics if you use these things.

    Helpful Sponsor Ads!





  2. bmblank

    bmblank Minister of Fire

    Joined:
    Jan 17, 2013
    Messages:
    668
    Loc:
    Michigan
    There's generally no moisture barrier in the attic like there is in the walls. Moisture passes through the drywall and condenses on the cold trusses, sheeting, etc. Seems like code would dictate a moisture barrier between the drywall and the insulation, but u suppose that can cause other issues too.
    I think the proper fix would be more ventilation in the attic. The moist air needs to be dissipated before it has a chance to condensate.
    ScotO likes this.
  3. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

    Joined:
    Nov 18, 2005
    Messages:
    28,057
    Loc:
    Northern Virginia
    Yeah there is a power gable vent. But it only runs when the temp up there is over 90 degrees. Looks like I need one that runs low level all the time.

    Gonna fog it this week to shut the stuff that is there down and then figure out what to do from there. The loose fill fiberglass insulation is probably full of the stuff.
  4. heat seeker

    heat seeker Minister of Fire

    Joined:
    Feb 25, 2011
    Messages:
    1,949
    Loc:
    Northern CT
    You can connect a humidistat to the gable fan to vent excess moisture. For the future, anyway.
    My ceiling insulation, FWIW, has a vapor barrier facing the house interior.
  5. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

    Joined:
    Nov 18, 2005
    Messages:
    28,057
    Loc:
    Northern Virginia
    If I could reach back to 1985 and get my hands on the builder's neck mine would have too.
  6. heat seeker

    heat seeker Minister of Fire

    Joined:
    Feb 25, 2011
    Messages:
    1,949
    Loc:
    Northern CT
    I hear you. One house I bought had a great looking attic. The insulation was covered, and there were walkways all around. Long story short - the moron had put all the insulation upside down, so the vapor barrier was on top of the insulation - holding the moisture in the insulation. And, he had stapled the barriers to the joists every couple of inches. You can guess how long it took my to pull all those staples without tearing the barrier, so I could turn the insulation over.
    Little damage, there was some mold over the bathroom, but the rest was okay. I asked him (later) why he did that. He said "because it looked better." This is the same guy who wired a 115 volt receptacle with 220 - because he didn't want to pay for a 220 receptacle for his table saw. Good thing I checked the voltage before I plugged anything into it. He also used the ground wire in some Romex for a third conductor in 3-way switch wiring.
    I could go on.
    This was a nice house, and he did a lot of beautiful carpentry in it. But his other work….yow!
    vinny11950 likes this.
  7. woodgeek

    woodgeek Minister of Fire

    Joined:
    Jan 27, 2008
    Messages:
    2,616
    Loc:
    SE PA
    Not a vapor barrier problem...an airsealing problem. Moisture doesn't go through drywall fast enough to cause that problem, and poly barriers are not recommended in VA. You have big openings in the floor of your attic carrying air (and that water) up there in the winter. They can be sealed with caulk or foam.

    Even after airsealing, I still don't go above ~30% RH b/c of worries about my wall cavities.
    semipro likes this.
  8. corey21

    corey21 Minister of Fire

    Joined:
    Oct 28, 2010
    Messages:
    2,215
    Loc:
    Soutwest VA
    I had been thinking of getting 2 humidifiers but after reading this i may pass. I have a few areas were the moisture could get up i the attic that is the reason.
  9. woodgeek

    woodgeek Minister of Fire

    Joined:
    Jan 27, 2008
    Messages:
    2,616
    Loc:
    SE PA
    A low level fan could just pull more moisture from your house and make it worse. Reverse direction is no good either...pushing the junk into your house. Just find a pro to come in and airseal it.

    Visualize this....When I bought it, the total area of openings between my attic and house was ~8 sq ft (which is pretty typical on 1960s construction). The venting in my attic to the outside was two small gable vents of a few square feet total. When I was running my attic fan, where do you think the air came from?
  10. ScotO

    ScotO Guest

    I was concerned about the mold issue when I built the scissor trusses out of my rafters in the living room project (made an old rafter ceiling into a scissor truss vaulted ceiling. After much research on the 'net (thanks to some info from Hogwildz and Jags, and others too numerous to mention) I ended up doing what I felt would be the best approach. I vented the ridge and the eaves, and put baffles in to make sure the insulation did NOT block the air flow. It really moves the air, let me tell ya. Insulated the entire ceiling to an R43 with no paper barrier. I then installed a vapor barrier of thick plastic, on the ceiling, taping all joints up to keep air from leaking through. Also bought the airtite light cans, sealed the vapor barrier around them with silicone, and they don't leak any air. It is amazing how well that has worked this winter. The snow on the roof does not melt off at all from heat loss, only when the sun hits it. Bart, what are you going to fog that attic with?

    I'd be seriously looking into venting your eaves and your ridge, and make sure the air has an open path to the peak (baffles at the eaves).
    woodgeek likes this.
  11. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

    Joined:
    Nov 18, 2005
    Messages:
    28,057
    Loc:
    Northern Virginia
    It is re-roofing time and a ridge vent will be part of that. The eves are well vented. I am gonna use Concorbium to slow the stuff down at the moment and figure it out from there.
    ScotO likes this.
  12. ScotO

    ScotO Guest

    If you do a roof, you'll have multiple options. Do a search on the 'net. I'd be looking into spray foam insulation if I lived in your climate/area....

    Right on the underside of the sheathing.
  13. fossil

    fossil Accidental Moderator Staff Member

    Joined:
    Sep 30, 2007
    Messages:
    10,185
    Loc:
    Bend, OR
    I'm very sorry you have to deal with that. We senior citizens do a lot better with little, easy problems. This one sounds big and hard. <>
    OldLumberKid likes this.
  14. corey21

    corey21 Minister of Fire

    Joined:
    Oct 28, 2010
    Messages:
    2,215
    Loc:
    Soutwest VA
    Sorry to hear about you having to re do your roof.

    My roof needs re done before long...

Share This Page