acceptable humidaty levels in gypsum?

2 part question.
After seeing ghosting in the closet adjacent the bathroom I performed humility evaluation on the gypsum.
Closet averaged 8% to 10% respectively.
Basement and under 500 sq-ft.
Lowest is 30" inches below grade to 0% at the back of the unit.
I did random sampling to form a hypothesis on(organic growth).
Higher levels of humidity in the wall board in a closet adjacent ( connecting too ) and the bathroom.
I covered the lowest and mid sections of the walls inside the closet, bedroom, bathroom.
I separated the unit into 2 parts, front and back half for my hypothesis. .
Back half = bathroom, bedroom.
Front= hall, kitchenette and living room entrance.
Front averaged relative humidity, the back half averaged 9.xxxx.
#1: Basement apartment.
#2: Wall samples averaged 9%+( bathroom and closet )
#3: 5% in the rest of the unit.
#4: The unit had been vacant for over 1 month.
#5: no visible signs of growth in the living araea.
#6: Signs of living plant and organic growth in-between window openings of the bedroom.
Unit in 5 years old. Windows are hinged mechanical, thermo pain, with exterior screen.
Screened area never cleaned.

What are acceptable levels?
Would a IR camera have been able to complete my hypothesis when investigating form mold?
PS: I studied the IAC2 course " and think " I remember that relative humidity levels under 17% percent are not conductive to mold growth.
I am going back to complete this cert.:slight_smile:

Other ares---------

Your meter has a +/- 3% accuracy range. Does your fancy meter have a drywall setting?

Thank you Linas.
The makers is GENERAL.
Yes it can be calibrated. To what extent is more a mathematical equation done after. I will post more.
No it is not fancy. 90 dollars at Home depot.
I am looking now into the settings Linas.
Mr.Adair kindly sent me some information on gypsum product and the article reminded me of settings.
Thanks Mr.Adair.
I have to pay more attention.:eek:

The moisture levels are not that bad, especially if the house is vacant. A 4% difference in moisture levels from one wall to another is suspect. It is common to have higher moisture in closets and bathrooms.
Mold can grow on drywall at 12%.

Point of correction:

Humidity is a reference to the amount of water in the air, not how saturated a material is with water. You would be better off referring to your readings as the percentage of moisture content or the saturation percentage. You measure relative humidity with a different kind of instrument all together and your wording could be misleading if someone would ever have to come back and verify your work.




OK Brian I am waiting for help please or a answer.
Thank you…Robert.
I understand your dislike for wording.
I asked you before, help or do not reply.RIGHT.
I will be civil but it works 2 ways Brian. You ether help repair something that is broken " as you state InterNACHI IS ", OR you help HI’S get up off the ground and give the public a better conclusion to the industry.
I am so confused by your attitude of being judging without evidence.?
That’s all.
Life is not complex. The industry is fractured in so many ways.
How do you improve it Brian?
A simple human value.
I should not have replied to Mr.Gillian so quickly. I did look for myself after.

Something you might not be aware of: Young’s main language is French so he does get his English words mixed up.

Relative humidity or absolute humidity are ways of expressing the amount of water in air!

So as to express the amount in material would be saturation.
This was in a thread months back.
PS first language is English.
Worked with french, Italian, eastern Slovakian mostly, and Italian.
Thank you Brian.
civility becomes most people.:slight_smile:

Wish it was that simple.
As explained several times, dyslexia caused by sever head trauma 40 years ago. 6 nero surgeons and happy to be here alive today. @ years of misunderstanding and a bright athletic possibility gone.

Then working with French Canadians talking a ( bastardized French language ) wife was Parisian, and having to think that way for 35 years compounds the translation in forming a sentence.
Again only when I rush out thought as on the MB…
If you knew the Quebec French language you would understand the translation from French to English.
A simple statement can be compared to asking a question.
Plus the amount of school lost and the doctors unable to see the problem at that time. Early 1970’s
Just thought I would explain again.
Henceforth I was on the job trained and learned by example. Watching.
Class B mason, class A Roofer, Class 2 cement finisher and ran most labor and job sites when I worked for large companies and held a specialized license that let me run almost all specialized equipment on a site.
Managed building 3 homes, not mine. I managed as the carpenter and GC.
Mr.Bushart warned me of the complexes while writing reports and seeking information.
I told him it will not wear me down.
Just a recap.
As I explained before, sorry but its the way I see written word Mr.Braun.
My spoken French is just adequate.:frowning:
Like I said I am not ashamed of myself. No need.:slight_smile:

Long story short, Mold growth starts at about 20% moisture content in materials. If your moisture meter read 17%, you would mention the possibility of mold growth and include a short explanation of the potential health hazards.

“Saturation” is the point at which a material can hold no more moisture and you wouldn’t comment on that. It varies with each material and there’s no reason to memorize all that.

Question Kenton.
Mr.Braun mentions 12% percent saturation in gypsum for organisms to grow.
I hesitate using the word living organisem but look for referral when reporting.
Its learning how to save and file that is next.
Opinion please.

Bacteria can actually grow on porous materials such as drywall and carpeting as low as 8% moisture content.

The article puts mold in a very basic easy to understand form. I could elaborate on some of the article if you wish such as, there are some medical tests that can detect mold exposure in extreme cases. I have doctors who refer me all the time because they can tell by running tests if it is fungal or not.

Kenton is probably referring to wood which can start mold growth at 20% moisture. The 20% would be the softer wood, particle board, OSB and plywood. It all depends on the hardest of the wood and/or the construction of the manufactured boards themselves.

Yes Mr.Braun I remember you are big on the understanding of residential organic growth. Strains of mold in particular.
I would enjoy some links please.
I am trying to save as much as I can. I will sort it all out in files and folders soon.
Thank Mr.Braun.:slight_smile:
Sorry for the edit. I did not see the post below.
Yes I am doing my IAC2 cert. again this week. Long story. I am familiar with the surfaces and the small amount of moisture and humidity need for various bacteria and mold spore to grow.
I am also partially deft Mr.Braun. Makes phonics a challenge to say the least. 2 hearing aids. No ear protection for 20 years of construction.
17 years ago at the hearing clinic the doctor was amazed I could here certain frequencies and others where not even audible at high decibels. Surprised I could here her voice and comunicate. HA HA.
I have tinnitus like a freight train in my ears, along with my eldest brother that is a distinguished cinematographer. Runs in the family. The hearing thing.
My understanding of written word takes time. Told you it was not simple.

This is the first I’ve heard of mold fungi growing at different moisture levels in different materials. I’ve always heard 20% and never heard that the material made a difference, but I don’t know enough about it to argue the point. I’d like to know the truth though. James, I’d like a link to good information too, please.

You did the IAC2 Kenton. It talks of 17% in wood but expands i,st thought.
Covers carpets, ceramics, etc.