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  1. #1
    Join Date
    Nov 2011
    Posts
    4

    Question Inside condensation & mold

    1500 sq ft home in Ky. In 2008 I had old roofing (2 layers w/o box vents) stripped and replaced with Owens Corning shingles and added 8 box roof vents. When the temp dramatically drops major condensation forms on one bedroom ceiling. This year it showed up as black mold. I have never had any problem with condensation or mold before. The only thing that changed was the new roof with vents. What is causing this? I have had the roofer redo a portion of the roof, I've installed additional insulation in attic and installed a sump pump in crawl space. Nothing has helped and no one can tell me what's causing this. I have no idea what to do but something has to be done. Please help.

  2. #2
    Join Date
    Mar 2012
    Location
    South Carolina
    Posts
    28

    Default Re: Inside condensation & mold

    So...your problem started in 2008 when you put on your new roof w/ the 8 box vents. What type of ventilation did you have before this?

  3. #3
    Join Date
    Dec 2010
    Location
    Houston Texas
    Posts
    2,370

    Default Re: Inside condensation & mold

    Do you have eave venting?

    Does the insulation block the path of air from the eave venting to the box vents?

  4. #4
    Join Date
    Nov 2011
    Posts
    4

    Default Re: Inside condensation & mold

    BloodSweatand....
    There was, and still are, vents in each eave. There may or may not be soffet vents...the siding was already on when I bought the house.

  5. #5
    Join Date
    Nov 2011
    Posts
    4

    Default Re: Inside condensation & mold

    Houston Remodeler......
    I may have my vent names wrong. There is a vent on each side of the roof....and there are now the 8 box vents in the roof. The vents under the roof edge (that I was calling soffet vents) that I think you are asking about...I've not actually seen them but assume they are there under the siding. I ask the guy who added the additional insulation if those vents were blocked and he said no. Something about baffles. Anyway, even if there were no vents that you're asking about there would not have been any of those vents before the new roof and there was no problem then with condensation. Thanks to both of you for responding.

  6. #6
    Join Date
    Jan 2008
    Posts
    1,109

    Default Re: Inside condensation & mold

    Part of the problem may be in the gable vents still being active after the new roof vents were installed. For an attic to vent properly the hot air escapes from the highest point, while the cooler air which replaces it comes from the lowest point. In this case the colder air is coming in through the gable vents, so there is no air movement below them. Look for soffit vents- the soffits are the flat part under the roof that extend past the walls of the house. There should be holes or perforations throughout the level areas, or there should be rectangular louvered vents across that area. Id there are the fix is simple- go into the attic and close off the gable vents on the sides. That will cause the cooler air to once again come in from the bottom and ventilate the whole attic as it once did before you had problems.

    Were this my house I'd delete the roof and gable vents and have a ridge vent cut in as it is by far the best way to let the hot air escape from your attic.

    Phil

  7. #7
    Join Date
    Nov 2011
    Posts
    4

    Default Re: Inside condensation & mold

    Mastercarpentry - Thank you so much. Your information is the first I've heard that has made sense and seems right to me. I probably won't do the ridge vent first but will close the gable vents and verify the soffet vents are working correctly. If that doesn't resolve the problem then I'll do the ridge vent. If this works...you are priceless! Thanks again.

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