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Question about mold

BILLB | Posted in Energy, Heating & Insulation on June 23, 2005 07:14am

Dear Friends,

Here is my scenario…new home built by a very competent and reputable builder. Recent weeks of very high humidity coupled with high temps (in the upper 80’s) and a delay in getting my geothermal HVAC system turned on (electric utility has not been by to power up the house) has resulted in mold growth on the engineered floor joists in the basement.

I’m sure turning the system on will dry out the basement, but will it stop the effects of the existing mold and mildew? Should I spry a diluted mist of chlorine bleach on the exposed surfaces?

If anyone has good experience with this type of problem, I would be grateful for your advice. I do not want long term health or building problems associated with mold growth.

Best regards,

 

 

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Replies

  1. FHB Editor
    JFink | Jun 23, 2005 08:59pm | #1

    I think you're right that the HVAC will clear up the moisture once it kicks in, but you should spray down that mold with a solution of borax--that will stop it's growth and keep it from coming back.

    Justin Fink - FHB Editorial



    Edited 6/23/2005 2:00 pm ET by JFink

    1. User avater
      BillHartmann | Jun 23, 2005 10:12pm | #3

      "I think you're right that the HVAC"Maybe, but they need to get a humidity guages adn monitor the moiture levels.In a new tight house a lot of them give off enough moisture that is more than the AC can handle and they might need a dehumidifier also.

      1. FHB Editor
        JFink | Jun 23, 2005 11:32pm | #4

        Point well taken, thanks for adding that note Bill.Justin Fink - FHB Editorial

    2. User avater
      rjw | Jul 10, 2005 03:47am | #8

      Justin - do you guys have any info about the borax stuff hanging out in the offices?

      View Image

      Sojourners: Christians for Justice and Peace

      1. FHB Editor
        JFink | Jul 13, 2005 04:25pm | #13

        Bob,

        I don't have any good info. on Borax, our go-to guy on that topic was Tom O'Brien, but we only have him as an author now. I can see if he has a website perhaps.

         Justin Fink - FHB Editorial

      2. User avater
        Soultrain | Jul 13, 2005 07:58pm | #14

        You can pick it up in the laundry aisle at the grocery store.

        1. FHB Editor
          JFink | Jul 18, 2005 09:53pm | #16

          I'm guessing that he knows where to get it, but is looking for some additional information in other regards. But I will let him speak to that point.

           Justin Fink - FHB Editorial

  2. User avater
    Luka | Jun 23, 2005 10:03pm | #2

    I learned something new here at Breaktime, and now I got to share it all over the place. LOL

    As Justin pointed out, A solution of borax will work.

    But so will a solution of anti-freeze. Better yet, a solution of both and some boric acid. (Same stuff as bora-care. A well known treatment for rot, mold, fungus and insects.)

    And don't worry, your pets and children are very unlikely to climb up there and lick the joists before they dry. And for the solution to do any damage to you, you'd have to actually drink a bunch of it.

    That mold will not go away. You can clean it off, but it will still be there in the fibers of the wood, no matter how well you clean.

    And it is already in the air, everywhere, anyway. Do people think that stuff only propagates and grows at the lumberyard and rides to their home on the lumber ?

    It is in the air everywhere, just floating around looking for a good home. You provided a good home for it. Now make that home downright unfriendly to it.

    =0)

    Are we there yet ?

    1. 4Lorn1 | Jul 10, 2005 03:32am | #7

      Recently learned something from a professor in building construction. His hobby is looking at old methods and finding out what they did, how they worked and why they used them a hundred years ago.His bit of wisdom on mould is the old country standby, seldom seen any more, whitewash. Essentially lime and water painted on wood to protect it. His recommendation is that exposed wood in crawl spaces and basements be whitewashed. The stuff stops insects and mold. It even adds to the fire resistance of the wood. This later point was pointed out when the NRC was testing the effects of nuclear weapons on structures. The normally painted buildings caught fire because of radiant energy at lower levels than the whitewashed out buildings. Seems our ancestors of a few hundred years ago knew a little something that we have lost. Simple and effective whitewash.You can make your own with unslaked lime, be careful as it can burn before it is 'slaked', allowed to absorb water and generates heat in the process, casein glue powder, chalk, flour and salt. This mix will resist a considerable amount or weathering. But given as that the areas being considered are not exposed to actual rain or elements plain lime, powdered chalk and water will work and last.It would be interesting to see is adding borax, washing soda, to the mix adds any useful qualities.I can testify that the man's crawl space was easier than most to work in. The limed surfaces were mold and insect free, except for the occasional spider, and the flat-white made the whole place both better lit and considerably more airy in feel. He said that once the floor joust and posts were set he applied the lime mix with a roller and rough brush taking little care to do it neatly. He did avoid getting it on the joist hangers. I'm not clear if that was to prevent possible corrosion or to placate the inspector. Once applied the sub floor was installed.

      1. User avater
        Luka | Jul 10, 2005 05:01am | #9

        Before winter hits I hope to try a mix of anti-freeze, borax and water. I may add dish soap, but I doubt I'll need it.I would add boric acid as well, but I can't afford even the 50 bucks for 25 pounds of the stuff. That'll have to be tried next year on some other building.I am going to try to get all the joists, but it'll be tough, since it is already crawl-space. Reason for going with the mix I am, is because I can spray it on with a garden sprayer, and thereby stay a bit farther away, while reaching a bit farther in where I can't quite crawl.I'll get all the wall cavities before I insulate and close them up. I am not the least bit worried about the anti-freeze being in them there walls. The bugs, mold, mildew and rot are a lot more of a threat to my health than some anti-freeze dried up and sealed away in the walls and under the floor.The anti freeze isn't going to chew or rot away the structure. Or crawl out and into my food, or to bite me. Or grow out, become airborne looking for a new spot to grow, and be breathed in.Interesting bit about boric acid on one of the links above. It is less toxic than aspirin. Roughly equivalent to table salt in toxicity.Anti-freeze in the house...I saw someone suggest environmentally friendly anti-freeze. First thought was GREAT IDEA !! Then I thought... waitaminnit. I am not trying to be friendly to the envirinment here. Environment being bugs, mold, mildew, fungus and rot. I want to be as unfriendly to them as possible.I do believe that for the regular stuff to be toxic once it has been sprayed and dried, you'd pretty much have to lick every sprayed surface in the house to get enough into your system, even to make yourself sick. Do that, and yer likely to get sick instead from all the other stuff you'd be licking up...The whitewash gives me a whole new direction to go.Hmmmm. Slaked lime, anti-freeze and borax ???You could make a paint of that. Probably be cheaper than real paint, but still more expensive than I can afford. I'll stick with thinning it down so much it can be sprayed.BTW: I think milk may have been substituted for the casein glue because it was cheaper and easier to get.

        Are we there yet ?

        Have you updated your forum profile lately? Please Do!To set your email address, click on your own name on the screen. In the pop-up window, choose "My Prefs". At the very top of the window, you will then see the place to change your email address. Please make sure that you enter a current viable email address. Otherwise you will lose your current history when you re-register.

        1. 4Lorn1 | Jul 10, 2005 08:30am | #11

          I wonder about the wisdom of the antifreeze formulas. Ethylene glycol smells, is oily and, according to historic records of WW2 British airforce, flammable. Supposedly it takes a lot to have it catch but when it does it burns white-hot. I have read that a couple of tablespoons full will poison a mid sized dog so its toxic. How the flammability effects the general risk of wood and how the toxicity expresses itself in residential setting is still a question. And I'm not sure if propylene glycol, the less toxic alternative, changes things. Is it as good at fighting mold as the regular stuff?Borax, or even chlorine bleach, sounds more of a sure thing. While the glycol are oily and might be hard to remove a good rinse should remove the worse of the bleach or borax. At least on the surface if it becomes an issue at a later date.The whitewash is a pretty well understood, but largely lost, method. Did some digging around the web and found out that as of the late 70s a lot of dairy farmers had their barns whitewashed yearly. Dairy regulations are, necessarily, quite strict so it would suggest that the whitewash is not too toxic or much of a risk. Found an interesting site from the US government:
          http://w3.gsa.gov/web/p/hptp.nsf/0/c91cab17e1ae7981852565c50054b626?OpenDocumentI note that under the title 'composition', and the second point, it shows that the materals beyond the simple lime and water were added to improve weather durability and chalking. Something that wouldn't be much of an issue in a basement or crawl space. Without the need to purchase binders the mix becomes even more economical. Lime, in a 50# sack, and water from the hose sounds pretty cheap.It also makes some suggestions. like Alum for preventin the coat from rubbing off and salt as a binder. Both are pretty cheap and available in bulk. Also I think neither of these materials would contradict the main reason for the mix, mould control or prevention. Some of the suggested addatives are more questionable, like the vegetable oil.On the same GSA page, a bit farther down, is a listing of mixes. I would think the 'Whitewash mix for general woodwork' would be a good start. 50# of hydrated lime, 15# of salt and 6 gallons of water making 8 gallons of mix. Assuming 200 square feet per gallon, I think it is a conservative estimate, you have enough for 1600 square feet. What does 50# of lime go for? Would be interesting to find out. I suspect it is very cheap compared with paint.Something I plan to keep in mind when I build my next shed. I'm thinking a lime, salt and alum mix and coat the crawl space and inside instead of paint. The flat white color should, even without the chemical action, discourage bugs and make the most of any illumination. Cheap is also a selling point. As long as it works I'm all over cheap.

          1. User avater
            Soultrain | Jul 13, 2005 08:04pm | #15

            "I wonder about the wisdom of the antifreeze formulas. Ethylene glycol smells, is oily and, according to historic records of WW2 British airforce, flammable. Supposedly it takes a lot to have it catch but when it does it burns white-hot. I have read that a couple of tablespoons full will poison a mid sized dog so its toxic."

            I use the 'safe' anti-freeze.  It is based on Propylene Glycol - it doesn't smell, it is much safer than Ethylene (still toxic, but you'd have to drink a glass of it), does not vaporize easily (meaning it will stay in the wood instead of evaporating into your home).  The glycol does more than ease penetration, it actually kills fungus, insects, etc.

            Timbor is fine, but it doesn't penetrate more than a 1/4" into the wood.  As far as soap dish soap goes, they contain glycerine which actually supports the growth of some molds (pick up your soap dispenser & notice the greenish-black ring on the counter).

  3. dabonds | Jul 09, 2005 09:08pm | #5

    What you really need is Timbor.  You can buy it at http://www.doityourselfpestcontrol.com.  It is not exactly the same as boric acid and is specifically made for the preservation of wood.  For interior application do not mix it with anti-freeze.  Anti-freeze for your car has many other chemicals in it besides ethylene glycol and none of them are healthy for you.  The advantage of the ethylene glycol is to achieve faster penetration of the borates into the wood.  If you live in an area where wood boring insects are a concern, mix a 15% solution of Timbor with hot water and some dish soap or tri-sodium phosphate.  Spray onto any exposed wood while the water is still hot for the best penetration.  This will afford permanent protection against mold, termites and carpenter ants.  If you are not concerned with insects then a 10% solution will suffice.  The borates will continue to diffuse through the wood at a rate that is proportional to the moisture content of the wood so your current high humidity situation will actually help with the process.  If you really want a heavy treatment wet the wood with a first pass of timbor/water spray and then, after the wood soaks it up, spray it again and again until it will not take more.  Timbor, by the way, also imparts a good bit of fire resistance to the wood so it has multiple benefits.

  4. Rafe82ABN | Jul 10, 2005 01:37am | #6

    Once you have the basement dried out you can just wash the mold off using a detergent solution.  You really do not need to spray it down first with bleach, borax, or anything else.  The mold will not continue to grow and be viable without an adequate moisture source.  The detergent acts as a surfactant to remove the growth from the wood's surface, much like soap for your hands.  towel dry the areas after you wash them.  You can lightly sand any stained areas. 

    I do like the idea of combining the mold removal with the preservative treatment mentioned above.



    Edited 7/9/2005 6:38 pm ET by Rafe_Padgett

  5. cliffy | Jul 10, 2005 07:16am | #10

     A two dollar bottle of javex will work just fine.

    Have a good day.

    Cliffy

  6. Mac2 | Jul 10, 2005 01:47pm | #12

    Might as well add my recipe for killing mold spores---which bleach will help clean but not kill.

    Amounts can be changed as long as the ration is kept.

    1/2 gallon of white vinegar
    1/2 gallon of hydrogen peroxide
    1 cup of boric acid

    Any solution saved must be in an air tight container, other wise the hydrogen peroxide degrades into water.

    I decided to stop taking life so seriously, it is, after all, only temporary.

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