# Attic Mold



## Rhizando (Mar 18, 2011)

Hey guys, new to the forum.

So I took a peak up in my attic yesterday and noticed I have quite a bit of attic mold. I remember hearing from an old timer that one solution to removing it was to leave a bunch of buckets of bleach up there. Of course you would do this when going away for a weekend, and after you have fixed the problem that was causing the mold in the first place. 

If you had attic mold how did you clean it up.

I am planning on installing adding insulation and putting a attic vent up.


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## HomeSealed (Jan 3, 2008)

Bleach will kill the mold, but before you worry about that, you need to address the cause. In my experience, an improperly routed bathroom exhaust fan is the number one cause, followed by lack of air sealing.


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## Rhizando (Mar 18, 2011)

I will have to check that out. I believe it was being caused by the lack of insulation. I think the previous owner only put r-11 up there. I live in Upstate, NY and know that I need a ton more. I just need to get up there and install it before next season. In regards to the ridge vent, how is it able to operate if there is a ton of snow on the roof?


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## HomeSealed (Jan 3, 2008)

Lack of insulation in itself will not cause mold (although it sounds as though you DO need more). Air-sealing will effectively eliminate any moisture in the attic, assuming that there are not other issues, such as an exhaust fan like I mentioned.


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## Rhizando (Mar 18, 2011)

I guess I was wondering if a ridge vent is limited if you have a foot of snow on the roof? I have soffit vents and a ridge vent but dont know how that combination would work in a very snowy region. Seems like a side vent would be a better option to get the airflow moving in the attic?


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## HomeSealed (Jan 3, 2008)

Regular box vents are even more susceptible to snow cover, as the very peak of the roof will be the warmest, and with a little help from gravity, does not retain snow cover for long. Even so, snow does not prevent airflow anyway.


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## gregzoll (Dec 25, 2006)

Soap and water is safer than Bleach, and will do a better job cleaning it up.


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## gma2rjc (Nov 21, 2008)

There was an episode of Holmes on Homes where the sheathing in the attic of a house was covered in mold. Mike had a company come in with a sand blaster to remove it. But they didn't use sand, they used dry ice and it removed all of the mold. 

I don't know if that would work for you, but it may be an option.


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## Rhizando (Mar 18, 2011)

Thanks for the help guys!


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## Oldeye (Dec 31, 2010)

Rhizando said:


> Hey guys, new to the forum.
> 
> So I took a peak up in my attic yesterday and noticed I have quite a bit of attic mold. I remember hearing from an old timer that one solution to removing it was to leave a bunch of buckets of bleach up there. Of course you would do this when going away for a weekend, and after you have fixed the problem that was causing the mold in the first place.
> 
> ...


There are many methods of killing mold.
The least expensive method is 50/50 bleach/water fine spray.
This method is good if you have adequate ventilation.
Other chemicals are available in Home Depo or Lowes.

The key to healthy attic space is really the ventilation.
You do not want to vent anything inside the attic as it will
add moisture level and aid in mold growth.
More of insulation and ventilation is a good thing. More the better.
There are minimum ventilation/insulation standards based on your 
attic size, never a maximum. You need to protect ceiling light boxes
if installed. I use sheet metal pipes around them. 

If soffit vents are not pratical, gable vents(if gabled roof) with
a power fan on the warmer side(South of West facing) is better.
The key is to flow the air out of the attic.

The most desirable method(passive vents only) is the soffit to
ridge type of ventilation. Again, more/larger the better. Make
sure to install insulation baffles to prevent blockage. Box type
vents with proper flashing are expensive by effective on 
certain hip styled roofs. Installed on the warm side as long as
soffit vents are available. 

Let me know what type of roof/attic you have.
What year was you home built?


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## Maintenance 6 (Feb 26, 2008)

You do NOT want to use a 50/50 bleach mix. 10% bleach is plenty to kill mold. More than that justs creates a dangerous breathing environment (chloroform compound gases are not your friend).:no:


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## cibula11 (Jan 6, 2007)

I had/have the same issue. I've done a 1 part bleach to 3 parts water solution in a pump sprayer. I had a pretty nice mask, but even then the fumes were pretty bad. 

The cause of mold in my case was an improperly vented attic. The soffit vents were completely covered by insulation. I installed new vents, and cleared them out (I would recommend using the foam or plastic rafter vents used to keep air flowing near the soffits), I also installed ridge vent. Haven't been up to check it all, but like mentioned, make sure NO exhaust fans are vented, insulate properly (probably R-45 in NY) and vent properly. Problem sovled.


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## MJW (Feb 7, 2006)

You most certainly can have too much ventilation and it is a bad thing. Too much ventilation can pull conditioned air out of the home and some vents can be actually pulling air into the attic, along with rain or snow or dust.

There are certified people that can identify, contain, and remove mold.


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## Oldeye (Dec 31, 2010)

Maintenance 6 said:


> You do NOT want to use a 50/50 bleach mix. 10% bleach is plenty to kill mold. More than that justs creates a dangerous breathing environment (chloroform compound gases are not your friend).:no:


I have had relatively safe results using this mix. 
Attic, in most cases, is an exterior space. 
I am assuming that the mold is growing on the sheathing
surface and that the sheating is rated plyboard. 

Obviousely, you have different types of attic spaces
where this method will not be safe. :thumbsup:


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## Oldeye (Dec 31, 2010)

MJW said:


> You most certainly can have too much ventilation and it is a bad thing. Too much ventilation can pull conditioned air out of the home and some vents can be actually pulling air into the attic, along with rain or snow or dust.
> 
> There are certified people that can identify, contain, and remove mold.


 
The only way you will get into trouble with too much attic ventilation
is if you installed them incorrectly and you have compromised air seal
from down below(the conditioned space). Attic is an exterior spaceand you don't want to use it for something else. The primary purpose of attic ventilation is to remove moisture and less blockage is better. I am assuming proper ratio of intake and exhaust sizing and protection from being blown off, etc. There are no parameters for maximum ventilation. Only the minimum or the ideal sizing. 

I am a certified mold inspector as well as ASHI certified home inspector.
I have done approximately 4,000 home inspections. Not as many mold
inspections, though, about 500 or so.


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## Rhizando (Mar 18, 2011)

By the way, the guy I had talked to said I didnt need to actually spray the mold. He said by leaving the buckets of bleach up in the attic for a couple days it would kill the mold.

Said to do it when I was leaving for a weekend.

Have you ever heard of someone doing this?


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## Oldeye (Dec 31, 2010)

Rhizando said:


> By the way, the guy I had talked to said I didnt need to actually spray the mold. He said by leaving the buckets of bleach up in the attic for a couple days it would kill the mold.
> 
> Said to do it when I was leaving for a weekend.
> 
> Have you ever heard of someone doing this?


Yes, I've heard of this method.
The efficacy of this method depends on how enclosed your
attic is. The bleach will evaporate a bit faster than H2O and
"fogg" your attic. But if you have reasonable ventilation, it 
will take a longer period of time as opposed to the fine spary
method. Direct contact kills the mold quicker. You do not have
to saturate the sheathing. Spray away from you and wear
a breathing mask and eye protection. 

This is the least expensive method and there are other chemicals
not as noxious but costs a bit more. 
MOLDSTAT is pretty nice smelling product but expensive.
You can order this through Ebay.
I use this for hand sanitizing and spraying around inside areas.
If you are afraid to the bleach, go to HomeDepo or Lowes
and ask around for what they have.


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## MJW (Feb 7, 2006)

Saying, "the more the better" on a DIY site is not a smart thing to do. Some may take that the wrong way and put vents every 2 feet on their roof.

I know a few home inspectors. They know the code book and thats about it.

Still, if you have too much ventilation, it can cause problems. I've seen it first hand many times, not just pictures in a book. No disrepect.


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## HomeSealed (Jan 3, 2008)

I'm afraid that I have to side with MJW, too much attic ventilation CAN be detrimental, especially when proper air sealing has not been performed. I've seen studies showing an energy LOSS when ventilation and insulation are added to an attic without proper air sealing. Unfortunately, many home inspectors are completely oblivious to this. I don't know your knowledge of building science Oldeye, and I do agree with some of your points, but facts are facts, and there have been some pretty major breakthroughs in the area of home performance/building science in recent years.


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## Oldeye (Dec 31, 2010)

MJW said:


> Saying, "the more the better" on a DIY site is not a smart thing to do. Some may take that the wrong way and put vents every 2 feet on their roof.
> 
> I know a few home inspectors. They know the code book and thats about it.
> 
> Still, if you have too much ventilation, it can cause problems. I've seen it first hand many times, not just pictures in a book. No disrepect.


 
You are right about some home inspectors.
However, you are wrong about them knowing "code book and that's about
it". The ASHI/NAHI Certified home inspector do not come cheaply. Most of my collegues have 4,000 plus inspections completed and keep up with continuing education(minium is 20 hours per year of class education).
Some of them are code certified. Most of us are very familiar as we attend
code seminars from time to time, especially if there are major changes, in building codes, that is.

Understanding codes is one thing but being an ASHI Certified home inspector is another. You can be both, though. Most of us do not do
home repairs except our own. It comes in as a conflict of interest in
our SoP manual. There is an one year off limits clause for repairs to
homes we inspected. Unless the damage was done during the home inspection.


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## Oldeye (Dec 31, 2010)

HomeSealed said:


> I'm afraid that I have to side with MJW, too much attic ventilation CAN be detrimental, especially when proper air sealing has not been performed. I've seen studies showing an energy LOSS when ventilation and insulation are added to an attic without proper air sealing. Unfortunately, many home inspectors are completely oblivious to this. I don't know your knowledge of building science Oldeye, and I do agree with some of your points, but facts are facts, and there have been some pretty major breakthroughs in the area of home performance/building science in recent years.


 
Okay, let's not get carried away.

I assumed that the living space was well sealed up.

The subject is about getting rid of mold on the cheap. 
We do not want to load the fellow up with all kinds of
heavy hitting building science scare!

I get no pleasure out of dragging any thing further.

Good insulation and ventilation are critical parts of
maintaining attic health. There are million ways to do it.
My suggestions are based on my personal experience and
training. Take it of leave it.:thumbup:


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