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how to address mold issue behind drywall

how to address mold issue behind drywall


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Old 01-11-17, 05:53 AM
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how to address mold issue behind drywall

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whats the best way to address the mold issue behind my drywall> the wall you are looking at is the wall to the back of my house. the bathroom sits in a dormer. the only piece of wood that is bad is the 2x4 under the window. this will all be fixed with the new window install. I'm going to be putting dura rock around the tub so is it necessary to remove any of the wood that has mold stains? the tub hasn't been used in years so all the wood is dry.
thanks for any suggestions.
 
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Old 01-11-17, 06:10 AM
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Mold needs 3 things to grow; food source [wood], moisture and heat. Remove any one of the three and it won't grow. Is the wood solid?

A bleach/water solution works well but needs to be rinsed. There are other products that work well and don't require rinsing but I'm not familiar with them. Fosters is one of the brands often mentioned.
 
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Old 01-11-17, 06:39 AM
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i'm aware why mold grows but thanks for the explanation.

at this point i doubt the mold is growing, as the bathroom hasn't been used in years. the wood is completely dry and as i stated in the post, only the 2x4 under the sill is rotten. my logic, whether accurate or not is that if no mold is actually growing at this point and the wood is still good, why couldn't i just cover it with dura-rock and move on with the project? i'm no expert on mold but don't want to miss a step before i cover the walls. if spraying it with bleach is the fix, than thats what i'll do.
thanks
 
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Old 01-11-17, 07:05 AM
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Bleach can eat the wood fibers so it needs to be rinsed. It's what I normally use on the exterior. There are products that don't need rinsing, I'm just not familiar with them. You do plan to replace the rotten 2x4, right?
 
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Old 01-11-17, 07:12 AM
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mark,
yes the entire window and frame will be replaced. back to my last post..... if the mold isn't growing and wood is good, can i cover it with dura rock?? thanks
 
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Old 01-11-17, 07:16 AM
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IMO it wouldn't be a problem, hang around and see what the others think
 
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Old 01-11-17, 07:24 AM
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that sounds good. thanks Mark.
 
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Old 01-11-17, 10:17 AM
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Discoloration in wood in older buildings is pretty common. Wipe things down with a wet sponge and you should be good to go. So, with the window replaced, does that take care of the moisture problem?
 
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Old 01-11-17, 11:01 AM
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Z asked my question - the reason for the mold is being/has been addressed, right?
 
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Old 01-11-17, 02:26 PM
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If you are using this wall as a shower wall and it is an exterior wall, pull that insulation out and replace it with insulation that fits better. I would recommend Roxul as it friction fits. If not Roxul, and you like fiberglas, make sure it fills the bays completely and has a continuous vapor barrier.
 
  #11  
Old 01-11-17, 07:43 PM
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Mold also needs air to grow. If you're worried about it, a cheap fix would be to remove the insulation and paint the wood with a couple of coats of an exterior paint/primer. Since the color wouldn't matter, you can check the local paint department for any mismatched exterior paint for sale cheap.
 
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Old 01-12-17, 03:09 AM
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While paint won't hurt anything I doubt it will help either. When mold/mildew isn't removed but just painted over it will come back sooner than it would if it was cleaned off .... least ways that's been my experience with painting exteriors and bath rm drywall.
 
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Old 01-12-17, 09:44 AM
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I can't figure out how priming/painting the wood would do anything other than take time and money from you.
 
  #14  
Old 01-12-17, 09:11 PM
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Exterior paints contain mildew resistant coating to prevent mildew formation because of wetness in the air that comes in contact with the paint surface.

Plus the paint bonds with the wood surface. Due to the flexibility and sealing qualities of the paint, it prevents air and moisture from reaching and reacting with any mold pores on the wood. Thus preventing mold to grow, due to the lack of air and moisture.

Interior paint will not work. You have to use exterior paint, preferably something with Microban, to retard and mold growth.
 
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Old 01-12-17, 10:05 PM
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I disagree. On the assumption you are correct, the best choice would then be a kitchen and bathroom paint.

Due to off-gassing, use of exterior paint inside is contra-indicated.
 
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Old 01-13-17, 02:55 AM
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Ya, you aren't supposed to use exterior coatings on the inside because the off gassing doesn't meet interior regulations. Extra mildewcide can be added to any latex paint but I don't see enough benefit to justify the effort.
 
 

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