Should I use bleach to remove attic mold?
First understand the purpose of bleach. It cleans stains, but does not have a surfactant to separate dirt. In your washer, laundry detergent is dispensed first. The laundry detergent has a surfactant that separates dirt from clothes. That water is washed out in the first rinse. Than the bleach is dispensed to disinfect and remove stains. The fabric softener is added last.
What does that have to do with mold removal? Bleach will kill some, but not all molds. The problem with bleach is dwell time. That is, how long will the product stay on the surface you are trying to clean. Bleach evaporates rapidly. Since bleach is made with water, it degrades to water. If you are trying to clean a porous surface, like wood, the water will absorb into the wood and the bleach will evaporate but will leave a lingering nasty smell. Remember that there are already lots of chemicals in the wood and there may be a reaction to the bleach.
Lets say you are a homeowner, you just had a home inspection and the inspector found mold in your attic, and your thinking you are going to clean it up with bleach. A few facts on bleach:
1. Although you can use it, chlorine bleach is a hazardous substance. The product we know as bleach is a solution of hypochlorite. chlorine and water.
2. If you mix chlorine bleach with any acid (vinegar, drain cleaners, lemon juice etc.) chlorine gas is produced. Chlorine gas is extremely dangerous and exposure can be fatal.
3. Bleach also cannot be mixed with ammonia. This is because the bleach reacts with the ammonia to produce nitrogen trichloride, which is explosive, and extremely irritating to the mucous membranes. (it has been used as tear gas)
So now you know how dangerous bleach can be, but you are going to attempt to do it yourself anyway.
Step 1. Protect yourself: You will at least need a chemical suit, a full-face shield with chemical cartridges and chemical gloves. The gloves are taped on and the suit starts retaining heat the minute you put it on. Hope you’re not a smoker because you’re stuck in the containment area for a while.
Step 2. Engineering controls: “Do no harm” is the creed of the mold removal specialist. That is to say, don’t create more damage than you started with. Protect the floor with 6 mill plastic, stapled and pulled tightly. There are two reasons for this. One is to collect mold debris and applied chemicals you are removing from the roof sheathing. Two is to prevent you from falling through the floor. You can’t walk on the plastic, but if it’s applied properly you can drag yourself around on it. The attic opening needs to be sealed while you are working in there.
- Set up a HEPA filtered air machine to help protect you from mold spores and chemical vapors.
- Set up negative air machines to move the air away from the living space. You do not want to contaminate others areas of the home.
Step 3. Feeling claustrophobic: You’re now in a moon suit, in a closed area. You have no contact with the outside world, (outside the containment area) and your words are garbled coming through the respirator. The suit is making you hot, the attic is even hotter, you can’t scratch an itch because of the gloves your wearing. Now start spraying bleach in the confined space. The respirator you’re wearing is already straining your heart, (restricted breathing) and the bleach vapors are stinging your eyes because the mask doesn’t fit right. Your spraying bleach above your head, it’s dripping on you and soaking through your suit and on to your skin. The bleach is eating the seals in the sprayers and they’re dripping everywhere. Heat exhaustion is setting in. Having fun yet.
But wait you forgot a step. The bleach is a cleaner and has no surfactants. Remember the washing machine. You need to use a detergent first to separate the mold from the wood. Go back and start over. Than you can apply the bleach to remove stains. After you get back from the hospital from having a chemical and panic attic, you still need to apply the anti-growth. Go online and find some mold anti-growth. First have the wrong stuff shipped. Go back and order the right stuff, but not enough because you didn’t measure it properly. Trot on over to the neighborhood tool rental store and rent an airless sprayer. These things work at 2500 P.S.I. and will take your arm right off. You put on a new suit and your back in the containment area. Your buddy is outside trying to figure out the sprayer, he gets it on, paint is coming out all of the fittings. It’s now spraying everywhere but the attic sheathing. Encapsulate paint is leaking into the kid’s bedroom from the attic. Your screaming, “shut it off” but your buddy can’t hear you. Your foot comes through the ceiling. The kids are crying, the dogs barking, and the carpet is covered in paint. You need a beer and your wife is not impressed.
Step 4. Should be Step 1. Call the IAQA professional mold abatement contractor you should have called in the first place. But he is not happy. His chemicals have ammonium chloride, and borate. Can’t be mixed with the bleach you have everywhere. Remember the section on “tear gas”. We will get it cleaned up eventually, patch the ceiling and replace the carpet. If you think that’s a disaster don’t even think about trying to “dry ice” or “soda blast” the attic yourself. Save yourself time, money, health and sanity and call a trained mold removal specialist. Your wife will thank you.
We can do this job for you usually in one day and do it correctly, with a warranty. Mike Quigley
Always use an accredited IAQA specialist to remove mold.
