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Insulating Crawl Space Found Mold on joists OH BOY!

Insulating Crawl Space Found Mold on joists OH BOY!

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  #1  
Old 12-30-10, 09:06 AM
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Insulating Crawl Space Found Mold on joists OH BOY!

So my husband cutout all the pink board to fit into band joists and since I am on vacation this week volunteered to foam seal them in. Lifted them out to trim a little smaller and saw mold. Black. Not in every one but in quite a few. Looking on down the line, they are also on some of the joists. Not sure if they are on the other far-end wall. We still have the faced (facing up to heated room) batting insulation in the ceiling as we have not finished the encapsulating/insulation process. The mold is not under the insulation on the running joists but it is at exposed areas.

I have read bleach is not a cure all. Was looking at :
Microbial Remediation | Cleaner | Chemical Supplier

Can I buy something with a chemical at Home Depot and rent a respitory mask & power sprayer.

I know I have to act quickly, and current economy is that no way can I afford to have someone come in & do this right now.

What have been your experiences via yourself or friends or ?

Took some pics with my cell phone. Will try to post them if I can figure out how.
Thank you in advance.
Anne

p.s. lil more info Crawlspace 25 x 13 ,was originally built with 2 side vents to code & insulated with faced batts. Due to cold we covered vents rudimentally with pinkboard tightly pressed in but not sealed. walls are 24" big block and floor is 2" of cement.
 
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  #2  
Old 12-30-10, 09:39 AM
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Bleach and water is a perfectly good treatment for mold

However, the question of why it's there in the first place needs to be addressed or it will come back
 
  #3  
Old 12-30-10, 09:52 AM
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Thanks Mitch. My husband talked to a chemist at a Pharma plant he works at & he seemed to agree that bleach would be an appropriate remedy.

It is definitely due to moisture. We sealed off those vents, but have not put a vapor barrier on the floor or block walls yet. Going to do that, and set up a dehumidifier. I want to wait now to install pink board until I know I solved the problem. Will gauge the humidity level every step of the way moving forward. Gonna clean off the mold with bleach. So glad I caught it now.

It really sucks because going into that crawl space = major thigh & knee bruising as I get in from my full basement, stepping up a ladder, face forward in *& legs out first. I dread going in there. Always afraid I might fall coming out.

Thank you so much for your response. If I have good results will report back. You always see people asking questions, but they never report back the results and that would be really helpful in my case!
Anne
 
  #4  
Old 12-30-10, 10:09 AM
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I would add that you don't want to use pure bleach, it needs to be thinned with water! Too strong of a mixture can harm the fibers in the wood. 25% bleach should work ok, if you go with a stronger solution - it should be rinsed off. Either a spray bottle or a pump up garden sprayer will work well for application.
 
  #5  
Old 12-30-10, 10:15 AM
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My husband has one of those spray type cans like you would see a pest exterminator use. So if we purchased your regular Clorax bleach, what would you reccommend the ratio be?

Also wondering, how long does it take to dry truly & completely? I want to press in that pink board insul & foam it closed at band joists.

I can't wait until this is successfully behind me.
 
  #6  
Old 12-30-10, 10:24 AM
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I'd start with a quart of bleach mixed with a gallon of water. You could go stronger but then you'd need to rinse it off after it dissolves the mildew. Using a fan to get the air circulating might help it dry faster..... if it doesn't kick up too much dust
 
  #7  
Old 12-30-10, 10:32 AM
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Thanks (Mark) Truly! Appreciate your response very much. AM feeling a little more confident now and not so hopeless!
 
  #8  
Old 12-30-10, 10:33 AM
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Normally 10% bleach to water is fine, Mark's recipe will give you a 20% solution so you should be all set
 
  #9  
Old 12-30-10, 03:54 PM
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Make sure it Dries in 24 hours are the mold could start back again
 
  #10  
Old 12-31-10, 06:35 PM
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Sounds like excessive moisture there..... Did you close the door to the basement/crawl? Is the heating unit in the basement? Are there ducts through the space, are they leaking?

You need to air seal around the rigid foam board at installation or moisture will pass there.

Is the crawl space dirt covered with a vapor barrier plastic?

Are the exterior downspouts extended away from the house-- find/control the moisture problem first. Any mud under the plastic on the ground?
Are you converting to a conditioned crawl space from vented; http://www2.iccsafe.org/cs/committee...E_06_64_07.pdf

http://www2.iccsafe.org/cs/committee...E_06_64_07.pdf

Gary
 
  #11  
Old 01-09-11, 11:55 AM
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Hi all, oh man still going back and forth on this.

We currently have batt insulation in the floor joists. We really need to pull all of it out & spray with the bleach mixture to kill the black mold on the rim & floor joists. The problem is I am in The NE area of the country and it is very cold and we can't really get this done in a day. I need the insulation to keep the room a little warmer.
Here are my ideas/observations & questions

1. Since the humidity level currently is bordering on 40% in the crawlspace, I am thinking that the mold cannot grow. Is this correct?
2. What is the lowest/most ideal humidity level in a crawlspace so mold does not grow yet it is safe?
3. Am thinking of purchasing a Santa Fe humidifier for the crawl space the reviews are great.
4. realized we had a downspout pouring right down into the foundation wall corner for about 2 years. We have corrected this about 3 months ago. Would love to strangle my husband for ignoring it for so long. But that is the area where the mold is emminating from.
5. Put a dehumidifier in the space set to 35% for now. It will kick back on in the event of a power outage.

So, my plan was, and I am definetly looking for feedback here: to wait until it warms up a little and I can do without the insulation, probably around april. So then I would pull out & discard all old batt insulation, spray/treat wood joists with a bleach mixture. I am thinking 20% bleach to water and wear an N95 respirator. Wait a few days until dry, then vacuum with a hepa vacuum. Wait two more weeks for wood to fully dry and re-install batt insulation as well as two levels of 6 mil vapor barrier on floor and up the wall. overlapped two feet and go all the way up the block walls. Two levels. Always running a dehumidifier in case the humidity levels go up.

What do you think?

Thanks again!
Anne
 
  #12  
Old 01-09-11, 12:08 PM
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also wanted to add, I believe correcting that downspout, and installing the vapor barrier on the concrete floors & walls is the reason for the moisture. No leaks in any piping or anything. We never had this issue pre the downspout even at 60% humidity levels in the summertime. I believe this is when the mold was thriving. Want to down the road pinkboard & seal, but would rather continue with the batt insulation for another year or two to make sure I can check mold situation
 
  #13  
Old 04-08-11, 10:20 AM
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wow.
Okay, two things:
1. absolutely, positively household bleach is NOT an effective mold removal option in this case! Bleach (sodium hypochlorite) is fine with imperious surfaces (tile, for example) but NOT for wood, etc. Clorox is highly diluted as it is, and it can not penetrate and kill the 'roots' of the mold. Use a true mold removal chemical from Home Depot or Lowes. You'll see they're about 5% sodium hypochlorite (vs 1% or clorox).
Oh, and that information comes from Clorox themselves. At best household bleach will wipe off the surface only; at worst you'll be giving MORE moisture to the wood to facilitate the fungi coming back!

2. If you sealed the vents only and didn't dehumidify the space, that's probably the problem. If open vents were the issue before, get a good dehum. running down there.

jP
 
  #14  
Old 04-09-11, 05:59 AM
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More likly it's fungus not mold.
Replace the vents with automatic opening vents, it's as simple as knocking out the old ones and sliding the new ones in.
If the crawl space floor is lower then the outside grade there's going to be standing water under the house. The grade under the house needs to be raised with fill dirt and cover over with 6 mil plastic as a vaper bariier with insulation ties bent in half holding it in place.
Any LOCAL extermiator company (NOT ORKIN OR TERMINEX !) can spray this for you and be done in less then 2 hours. They would coat the wood with a soloution of Boric acid (BORON) and water. It will kill the fungus and keep it from coming back and any other wood boring insects that ever try to eat it. It's the cheapest treatment that they do. You could do it your self with a pump sprayer, but wait until you see how much fun that is.
 
  #15  
Old 04-23-11, 07:32 PM
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bleach and scrub it. wear a mask too though. black mold or potentially any type of fungus can be dangerous.

More reading ...... mold removal
 
  #16  
Old 04-23-11, 07:55 PM
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Any color mold can be dangerous. Color has nothing to do with it! The sensitivity of the occupants do.
 
  #17  
Old 04-26-11, 08:52 AM
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First of all mold needs food and water to live and grow.
You cannot take the food away, as that is the wood itself.
Therefore you must remove the water!

Mold spores cover the world from North Pole to South Pole.....yet you do not see mold everywhere.

Mold only forms in certain conditions.
The wood needs to be cold and there needs to be a regular supply of water.

With a basement or crawl space, the floor or the room above is usually warm enough to direct the water vapor in the air to somewhere else that is colder.

Water vapor is suspended in warm air until it meets a cold surface, the air cools the water drops out as condensation.

The condensation makes the wood wet, the mold spores start to grow.

The key things are to keep the room above warm and thereby keep the floor and joists warm.

By adding batt insulation between the joists you keep the floor above warm......but, destroy the air convection currents and that make the joists cold. Cold joists attract water vapor in the air.....and your problems start.

After you have washed the mold off the joists with soap and water, there is no rush, mold will not jump in and start again.

Box in the floor with at least two inches of polystyrene sheet, Cover the whole or the underneath of the floor with tightly butted sheets of polystyrene to keep the warmth in, once the joists are warm, there will be no more mold. Use spray foam, to fill any gaps that the heat may escape through or the water vapor gain access through.

When you write about humidity, writing 40% humidity means nothing.

To make sense you must include the temperature. Humidity is always referred to as RELATIVE HUMIDITY as it is only when the temperature is known, that one knows if the air is dry or wet and if you mention the time it also helps.

Air at 40f at 100% saturation holds one teaspoon of water vapor per cubic metre. (It is to all intents dry)

Air at 86f at 100% saturation holds five teaspoons of water vapor per cubic metre.
(And that is as wet as air can get)

If you take a typical day at this time of the year and if you monitor relative humidity over the 24 hours you will see that the relative humidity during the night is almost always at some point 100% and once the sun comes out and the air warms it drops to perhaps 30% or 35%.

Once you get down to a temperature of 40 degrees fahrenheit, humidity becomes of no importance as the air is almost dry, it holds one teaspoon of water vapor per cubic metre.

A typical unheated basement/crawl space has a temperature of about 40f (unless there is warm wet air blowing in)

Using a dehumidifier in a basement/crawl space is a waste of your money as it will do nothing to help, you will merely be trying to dry out America.

You should only use a dehumidifier in a almost air tight room, otherwise water vapor from outside will head straight for the dehumidifier to condense, you collect lots of water feel happy, but......its water from outside, that without the attraction of the cold surface of the dehumidifier, would have stayed outside.
 
  #18  
Old 04-29-11, 02:20 AM
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I used to be a state licenced exterminator, and I now have to deel with this problum on a daily basis while remodeling 100 plus year old homes.
Never once have I seen a pro exterminater use or suggest using bleach as a treatment for fungus under a house.
A solition of Boric acid in one form or another is always used.
Boric acid - Wikipedia, the free encyclopedia
Bleach will kill what mold is there now but once it evaperates it will just grow back.
Boron dehydrates the mold and if anything from carpender ant, termites, boring bees, powder post bettles try to eat the wood it will kill them also.
If you can find a product called Roach Away in the insectacide area in any place from Wal-Mart, Lowes Home Depot and mix it with really hot water and put it in a pump sprayer and just spray it on the wood the fungus will die.
Roach Away is 95% Boric Acid.
A moist crawl space can be caused from many things, if the grade is lower under the house then outside, then the grade needs to be raised by adding fill dirt under the house.
If the outside grade runs toward the house it also needs to be regraded.
If there's mulch piled up againt the foundation, all it's doing is holding in the moisture.
If you have a flower bed right up againt the house then you just made a pond that leaks under the foundation.
If the down spouts just drain to the base of the foundation it also will end up under the house.
Closed up vents, no vaper barrier on the ground is a 100% sure way to have fungus growing.
I've seen dozens of homes with dehumifiers in the crawl spaces, most had rusted out long ago or just were no working because no one ever went under the house to check on them. They also cost as much to run as a small A/C unit.
And where are they dumping all the water there collecting? You will need a pit, a sump pump with a check valve and a line leading at least 10 ft. from the house if you do go with a dehumidifier.
 
  #19  
Old 05-16-11, 07:23 PM
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Concrobium.com buy the fungicide and rent the fogger at Home Depot. Bleach is NOT what you want to use for mold/fungi. Seal your foundation vents closed, PERMANENTLY and install a dehumidifier. Problem solved.
You may want to make certain it is actually mold/fungi. if you have a damp crawlspace with camel crickets, their excrement, which gets deposited all over your subfloor, is often mistaken for mold.
 
  #20  
Old 05-17-11, 08:12 PM
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Fogger are not good enough. Rent an airless sprayer and soak it down
 
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