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Help I’ve got serious moldy floor joists

| Posted in General Discussion on April 1, 2002 02:04am

Been building for 24 years (not a rookie)However…Treid to build a home on a 4 block crawl in Indiana ( my own home) next thing I know there is 1/8″ mold all over the underside of my floor system.  NOW i have the vapor barrier & venting down but the mold is left.  It’s my own fault ,I know because i took too long to install these and went through 4 seasons without them.  WHAT I NEED IS TO KNOW IF THERE IS A SAFE EFFECTIVE METHOD FOR ITS REMOVAL. Any thoughts would be greatly appreciated!

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  1. silver77 | Apr 01, 2002 02:22am | #1

    Hey miammi,

    I had a similar problem when I built our house because of water in the basement. There was lots of mould on the floor joists and bottom of the plywood floor.

    I had my son spray a strong solution of liquid bleach and water soaking everything twice with a garden sprayer while wearing a respirator and eye protection. It cleared up all the mould. I think it was about 25% bleach/75% water. Your local health unit would know the exact formula.

    Hopes this helps-

    silver

    1. finebuilder | Apr 01, 2002 04:31am | #4

      Hey Silver, I really appreciate your fast responce.  I will absolutely try your solution. It is good to know that I can learn from your experiences. Really, REALLY apreciate the help!

      Sammi

      1. silver77 | Apr 02, 2002 08:20am | #14

        hey miammi

        I'm out gunned and I stand corrected but for what it's worth:

        the weak bleach solution killed the mould completely and cheaply

        with no structural damage using what was on hand.

        If you wanted to paint or stain over the bleach, that wouild be the real problem with bleach.

        fast, quick, easy; sometimes thats part of it

        knowing what I know now, and if copper sulphate is nontoxic, I'd give that a blast; wish I had this board for advice then.

        good luck

        silver

        1. finebuilder | Apr 02, 2002 03:39pm | #15

          Hey Silver, I appreciate your help and practicality. I think that I can swing the copper but many who post here may not ( at this time) be able to.  We've all had times of "feast or famine". On another side trail; how come you're called silver? These names intrigue me.  I go by Miammi Sammi because my friends think that I remind them of a gypsy trader, my name is Sam, it just stuck I guess.  For that matter, anyone signing on who would be willing to explain their name; I would really like to read it!  I know it sounds odd...perhaps it's just my nature. Any names would be welcome.  I've gotta go replace another bathroom. I'll post on later tonight.

                                                                         Miammi

          1. Fred_Lugano | Apr 04, 2002 07:09am | #17

            Dear Sammi,

            Are you from Florida?

            There is no need to poison the lumber with any type of chemical. I've bleached a number of cellars and crawl spaces. It's no fun.

            To stop mold from growing, you only need to eliminate water supplies so that the lumber dries to less than 20% moisture content.

            To remove surface mold, and the bio-toxins that we need to be concerned about, you can scrub with soapy water.

            No matter what you do, if the supply of water continues to keep the lumber too wet, you will get more mold.

            Regards, Fred

            [email protected]

        2. Frandn | Apr 04, 2002 06:13am | #16

          Hay Silver --- you did good. Bleach does kill mold because the same principle is used when those who have swimming pools have to "Super Chlorinate" to kill the mold. The only difference is swimming pools are not normally made out of wood! Well, there may be a few but I have not seen of one.

          Just so there is no misunderstanding, I believe everything can be toxic --- particularly when done or consumed in excess. Please remember that any chemical should be treated with respect. Always wear eye, face and outer clothing protection when using chemicals.

          All of the methods outlined in this thread will work. I am not a microbiologist nor do I pretend to be (I am just a lowly chemist) but I have used the methods that I have previously mentioned with success.

          Whatever you do, just be careful and Good Luck.

  2. User avater
    rjw | Apr 01, 2002 02:56am | #2

    I have read that you shouldn't use a chlorine type bleach on wood; that it can deteriorate it.  (I don't recall the source - it might have been "Consumer Reports" in it's article on deck sealers a few years ago.

    Try a google search.

    There's beena lot of heat and emotion about mold lately; people that I respect are saying that when you have it; kill it and control the moisture to keep it from coming back.

    1. Mooney | Apr 01, 2002 04:15am | #3

      I just built a new house this last year for a rental. Renter called and said she had mold in every window. I asked if she was using her bath room vent fans when showering and she said no. I went under the house and I dont have any mold visable. Still it will be my fault if I dont cover the underground with vesqueen. I was called out on another one that wasnt mine this last year that looked as you say yours does and the lumber had sagged. I had to replace the joists. Hurry and do something. Truth be known there is damage already.

      Act now,

      Tim Mooney

  3. User avater
    BarryE | Apr 01, 2002 04:39am | #5

    There was a house similiar to that here in Central IA. House went thru 3 different builders and set in various stages of finish for a couple of years. The family that brought the house were sickly the time they lived there.

    After they moved, an inspection was done and the joists and underside of the floors were found to be covered with a thick black mold. It turned out to be Stachybotrys, a sticky and toxic mold.

    It seems the only way they can get rid of it is to completely remove the joists and flooring and replace.

    It might be wise to have it tested.


    It's not the habitat, it's the inhabitants.

    Won't you be my neighbor


    1. Frandn | Apr 01, 2002 07:16am | #6

      An effective way to kill mold, especially the really bad type such as the black mold would be to use a copper sulfate solution. I would suggest a weak concentration of only 2%. You can purchase copper sulfate at most feed mills or animal supply stores. There are several brands used for fungus infections on cattle such as "Copper Tox" but the real granules are generally found at the feed mills.

      1. Piffin | Apr 01, 2002 01:39pm | #7

        Copper to kill on the surface but might need one of those boron treatments to inject.

        Excellence is its own reward!

        1. hausdok | Apr 01, 2002 02:04pm | #8

          Hi,

          Treat the underside of the home with a borate solution. Sodium borate is toxic to all forms of fungi and unlike copper sulfate is non-toxic. An especially good product for this type of application is BoraCare. It is about 20% borate by volume - pretty strong in terms of borate-based products - and consists of a mixture of borate and glycerin. The glycerin helps the solution soak into the wood up to a depth of 1-1/2 in. and slows down evaporation so you get better dispersion. It isn't cheap - about $100. a gallon - and you need to cut it 1/1 with water and apply it with a pump sprayer. Once treated with this stuff, the wood will be toxic to mold, as well as insects who consume wood, forever.

          I don't know who sells the stuff in your area, so try contacting Wood Care Systems at 1-800-827-3480 and ask if they know who the local distributor is. While you've got them on the phone, you might quiz them on what other solutions they recommend. These guys are specialists in this kind of thing.

          ONE TEAM - ONE FIGHT!!!

           

        2. Frandn | Apr 01, 2002 06:35pm | #9

          My experience is that mold will only grow on the surface, as the spores will only propagate when exposed to warm moist air. Check out the food in the back of your refrigerator and you will see mold only on a surface. If you can kill the mold on the surface then the job is done and copper sulfate is better than bleach. The pH of bleach is high enough to destroy the lignin in the wood and cause the wood to fall apart --- this is how the paper industry makes paper from trees. Good Luck!

          1. Tesaje | Apr 01, 2002 06:42pm | #10

            It isn't true that mold only grows on the surface.  The mycelium is the body of the mold and what you see is usually only the fruiting surfaces.  The mycelium can be much, much larger than the fruiting surfaces.  It isn't advisable to eat the bottom of moldy food for this reason - it is likely the mycelium has grown throughout the food substrate.  The longer the mold has to grow, the greater the chance it will be in the body and more damage it will do.  Mold is nature's way of rotting things to put the nutrients back into the soil for the next round of plants.Mary

            Gardening and remodeling in Zone 6, MD

          2. Piffin | Apr 01, 2002 07:27pm | #11

            Definitely not true!

            the fine hairlike threads of the roots of this stuff are mostly microscopic but they spread the canker all through the pores of the wood.

            A search for Timbor product name will lead the right doirection for sources and studies. I think it was U of Illinois that has some major studies on use of boron treatments for stopping spread.

            Keeping it dry is the first rule.

            Excellence is its own reward!

          3. finebuilder | Apr 02, 2002 05:33am | #12

            Wow you folks are like rocket scientists!  I feel like I need to retake chemistry just to understand your replies!  Thanks so much for all the help.  Am I right in understandind that Bleach would work, but has no real penetration and harms wood potentially?  The copper sulfate seems to be the best long term solution, correct?  I feel like Forrest Gump in a Quantum Physics class.

          4. Piffin | Apr 02, 2002 07:41am | #13

            The copper is best for a surface treatment to knock it back. Similar products in a weaker form are used as a preventative on fruit trees subject to molds and fungus diseases. they need to be re treated every so often.

            The Boron is inserted into the wood. You can use a liquid spray or penetrant but they have a product called Timbor which is a solid rod. You drill a few holes the same diameter as the rod and stick it in. Whenever there is enough moisture to support molds or fungus growth, a portion of the boron disolves and migrates by capillary action along the lignum fibres of the wood. These are like long narrow drinking straws so it isn't hard. So the preservative spore killer is slef dosing whenever conditions are right for growth of the fungii or mold in the wood.

            More biology than chemistry at this point but if the rot takes over, the laws of physics will give you a refresher course.

            Gravity rules!

            Excellence is its own reward!

          5. hausdok | Apr 05, 2002 03:16pm | #18

            Hi Piffin,

            Pretty good explanation of boron. Minor correction. Timbor is a powder that is mixed with water for a surface boron treatment (10% boron by weight). BoraCare is a liquid that is mixed with water for a penetrating treatment (20% boron by weight). Impel Rods are the boron rods inserted into the wood to act as sort of a nicotine patch for wood. They come in plenty of different sizes for different dimensions of lumber and have to be properly sized and inserted at proper intervals to be effective.

            ONE TEAM - ONE FIGHT!!!

            Mike O'Handley

            Bungalow Rescue, Seattle

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