# Mold on my new, unpainted drywall... no H20 please look and advise!



## Jrmsign (Jun 5, 2011)

New, unpainted sheetrock, installed in Feb of this year, building is dry, and I have mold growing on the sheetrock! Strange thing is that some sheets have crazy mold growth, while the sheet next to them has almost none. Sheetrock came in one unit and was installed immediately, not stored before installation. Thats the short version, please see the pics and let me know if there is a safe way to salvage this sheetrock (not the 6 bad sheets, but the 80+ that have mild mold) sheets are 5/8" thick 4' x 12' sheets.


Now the longer version with more details:
This is on my own building, put up a barn in my backyard, 30' x 70' building, first 50' has a 14' ceiling, the back 20' has a cathedral ceiling for a lift. There is a 16' x 50' rec room above the 14' ceiling. Building is wood, asphault shingle roof, r-19 insulation in the walls, r-30 above the 14' shop ceiling, and again in the roof.

I put the building up last summer, cement in October, insulation in January, sheetrock in Feb 2011. All was well until today. 10 days ago I was in the barn and sheetrock was fine, I was looking at it discussing options of 1 coat of tape vs 3 for the shop, and white primer finish. This morning I go out there and at first I thought someone popped an oil line, there was crap all over the ceiling. Upon closer look, its MOLD, the strange thing is that some sheets of drywall are covered with black spots, othere have very mild spots, just getting started. The sheetrock is dry on the front, and the back, insulation is dry. I cut a hole in the worst sheet and the back of it is perfect. no leaks, no standing water. check out the pictures please, its very strange that random sheets in the building are covered with mold, and others have none, or very little.

I called my supplier, usually very helpful, not today. They claim it can't be anythign with the product.... not even my primary concern, the material is the least of my concern. I need to figure out why this happened, and if it is safe to keep the sheets that only have the mild spots on them so far.

I am going to remove the bad sheets, ther are only about 6 of them (100 sheets total) there are about 5 with no visible signs of the mold at all, and the other 80+ sheets have mold that wipes off with a dry paper towel, and there is no visible sign of the mold after you wipe it.

those are the sheets I am concerned with. Is it safe to wipe with bleach and keep them, or should I remove it all and get the mold out of my brand new building?

Other details:
Garage floor has always been dry, no water leaks or weaping up thru the floor. there are (2) 12' x 12' overhead doors, neither of which have the weather stripping installed around them, so there is about a 1" gap around the perimiter of the doors that I would think would provide air flow... no actual vents in the building until today... I just installed a 16" fan with louvers on the gable end, and I have 2 fans blowing air into the space with both doors open just to get some air circulating.

Worst mold is in the ceiling, there is mold on the walls too. above the sheetrock in the ceiling is a plastic vapor barrier, then r-30 insulationwhich is inbetween 12" trusses 24" on center, above that is 3/4" TG osb flooring for the rec room. THe rec room has r-30 in the knee walls, and the ceiling, trusses are vented with the styrofoam baffels over the insulation, the soffits are still open, and there is a ridge vent the length of the builging. Upstairs is not sheetrocked, and there is no sign of mold on any insulation, or any studs or sheathing, only on the inside surface of the 5/8 sheetrock.

My gut feeling is that there was something on at least the 6 bad sheets that started to grow once it got warm outside. we had rain and heat the last two weeks, but it was always nice inside the barn.

Sorry for the long post, any advice would be greatly appreciated!

Thank you.

John Morrison


----------



## griz (Nov 26, 2009)

Jrmsign said:


> ... Is it safe to wipe with bleach and keep them, or should I remove it all and get the mold out of my brand new building?
> 
> Other details:
> Garage floor has always been dry, no water leaks or weaping up thru the floor
> ...


Heck of a first post. Your location would be helpful.

Where is the drywall from?

Have you done a moisture test on the slab? Is there a vapor barrier under it?

The part about the building not being vented is troublesome. 

Bleach will not remove mold. The problem with mold on sheet rock is that it gets in to the paper & then the substrate. You can have it tested so you know what you are dealing with. A call to a mold remediator might be helpful.


----------



## Morning Wood (Jan 12, 2008)

That is weird. I too would be worried about the mold getting behind the paper and onto the gypsum. If that is the case, replacing all of it would be the best option.


----------



## TimelessQuality (Sep 23, 2007)

griz said:


> Heck of a first post.
> 
> 
> Is there a vapor barrier under it?



I think Griz got it... 

Get some air circulation going in there, and call a contractor...


----------



## Tim0282 (Dec 11, 2007)

I think the combination of no vents and the plastic on the ceiling is a killer. I don't like plastic on the ceiling. Had too much trouble with it in the 80's here in Iowa. (mold on the ceiling) Your air flow, or lack of it was the beginning of the problem. It just jumped out when the season changed. Tough one! Feel your pain!:sad:


----------



## Big Shoe (Jun 16, 2008)

Bad things seem to happen when drywall just sits unfinished and unpainted for long periods of time.

I would try a bleach water solution in a pump sprayer and wipe it off.

The way it affected the sheets could be they were made in different batches,different days,different recycled paper. 

Unpainted drywall is very pourus and will ''suck-up'' moisture.

Jrmsign, What has the worst mold,the joist ceiling or the truss ceiling?


----------



## CompleteW&D (May 28, 2011)

In the first picture it almost looks like a garage door track which would indicate the joist ceiling. So the combination of all of the above and maybe some wet lumber sitting for so long with no protection, that paper would be like a sponge. Replacing what's bad and at least a solid coat of high quality primer should stop any further mold I'd think. Along with getting some decent ventilation in place of course.


----------



## Jrmsign (Jun 5, 2011)

The joist ceiling which is flat, 14' above the slab floor is the worst, some sheets bad, some sheets barely have any mold on them at all. the truss ceiling which is pitched and extends to 26' above the floor barely has any mold on it. I did not put a vapor barrier under the concrete - concrete contractor said it would make the floor harder to finish, and allowing the concrete to cure from the top and bottom was he way to go unless building inspector made me put plastic down. There is 12" of gravel below 8" of cement, the floor has always been dry to look at, but there is cool basement feeling in the building. I put a 16" power vent in the gable end yesterday, installing a large dehumidifier today (permenant) and I tried wiping the surface of the sheetrock with a sponge mop and 2 to 1 mix of water and bleach. Even the worst sheets came clean easily with the bleach. I plan to remove the sheets that are bad no matter what, pulled 2 sheets down, absolutely no sign of mold on the back of the sheets, or even the edges where the sheets meet, just on the face. I am considering spraying the seams with a bug sprayer with the bleach and water mix, and washing the surface with the mop... Absolutely sick over the idea of taking out all of the sheetrock, but don't want to get sick from the mold.

Thank you for all of the good suggestions. I have servepro coming later today. I also talked to a painting contractor who told me to just wipe it down with a sponge and bleach, let it dry and not worry about it, he said it happens all the time. I don't think what I have here happens all the time! but he seemed to think the bleach on the sponge would do it since the mold started on the face, and doesn't seem to have penetrated the sheets. I will try peeling the paper off a sheet and see if it is stained on the back of the front layer of paper.

Have a great day, thanks again for taking the time to help out.

John


----------



## Jrmsign (Jun 5, 2011)

*Reply from John*



griz said:


> Heck of a first post. Your location would be helpful.
> 
> Where is the drywall from? *Drywall is from National Gypsum, made in usa*
> 
> ...


* Thank you*


----------



## Jrmsign (Jun 5, 2011)

*Reply from John*



Big Shoe said:


> Bad things seem to happen when drywall just sits unfinished and unpainted for long periods of time.
> 
> I would try a bleach water solution in a pump sprayer and wipe it off.
> 
> ...


The joist ceiling which is flat, 14' above the slab floor is the worst, some sheets bad, some sheets barely have any mold on them at all. the truss ceiling which is pitched and extends to 26' above the floor barely has any mold on it. I did not put a vapor barrier under the concrete - concrete contractor said it would make the floor harder to finish, and allowing the concrete to cure from the top and bottom was he way to go unless building inspector made me put plastic down. There is 12" of gravel below 8" of cement, the floor has always been dry to look at, but there is cool basement feeling in the building. I put a 16" power vent in the gable end yesterday, installing a large dehumidifier today (permenant) and I tried wiping the surface of the sheetrock with a sponge mop and 2 to 1 mix of water and bleach. Even the worst sheets came clean easily with the bleach. I plan to remove the sheets that are bad no matter what, pulled 2 sheets down, absolutely no sign of mold on the back of the sheets, or even the edges where the sheets meet, just on the face. I am considering spraying the seams with a bug sprayer with the bleach and water mix, and washing the surface with the mop... Absolutely sick over the idea of taking out all of the sheetrock, but don't want to get sick from the mold.



Thank you for all of the good suggestions. I have servepro coming later today. I also talked to a painting contractor who told me to just wipe it down with a sponge and bleach, let it dry and not worry about it, he said it happens all the time. I don't think what I have here happens all the time! but he seemed to think the bleach on the sponge would do it since the mold started on the face, and doesn't seem to have penetrated the sheets. I will try peeling the paper off a sheet and see if it is stained on the back of the front layer of paper.



Have a great day, thanks again for taking the time to help out.



John


----------



## Jrmsign (Jun 5, 2011)

*Reply from John*



Tim0282 said:


> I think the combination of no vents and the plastic on the ceiling is a killer. I don't like plastic on the ceiling. Had too much trouble with it in the 80's here in Iowa. (mold on the ceiling) Your air flow, or lack of it was the beginning of the problem. It just jumped out when the season changed. Tough one! Feel your pain!:sad:


Thanks for the reply. This is frustrating, I have to say, I washed with bleach and water on a sponge mop, stuff came off - or at least appears to have come off completely. Even the sheets that were the worst - very strange. I am removing the sheets that were the worst ones today, and probably a good chunk of another sheet that just has a little on it, to keep them as a test (not sure where to put them, don't want mold in the house or the barn!) but if I paint what is left, I want to have something to keep an eye on to see if these cleaned sheets start to grow mold again, so I know to check my painted sheets in the barn. If I was giving the advice I would be saying just remove it all, get the mold out of your new building and start fresh, perhaps without the plastic on the ceiling. Definately the safest way to go, can't stomach the idea at the moment.

*Nobody seems to think this is the result of bad sheetrock? My gut reaction was that the sheetrock CAUSED this problem?? The fact that some sheets were covered with mold, while the sheets around them had none, made me think the sheetrock was contaminated with something that started to grow when we got to summer. Anything in the barn itself would make the same problem on all sheets - no?*


----------



## JHC (Jun 4, 2010)

Spray it down with Bin. Alcohol will kill it. 

Put two top coats of exterior quality grade in what ever sheen you desire.


----------



## Sir Mixalot (Jan 6, 2008)

griz said:


> Your location would be helpful.


Jrmsign, Where are you located? :detective:

-Paul


----------



## Tim0282 (Dec 11, 2007)

When the concrete guy doesn't put plastic under the concrete, you will always have a wet floor when the temperature changes quickly. Spring/fall. Too bad. They didn't put any under my garage floor, either. Nice! Gets very wet and very slick a few days a year. And my drywall opens up when it gets that wet. The moisture comes out of the ground right through the concrete. If I didn't open up and dry it, it would surely grow mold. Yes, the concrete is slower to set up so they can trowel it, but sure beats the forever moisture problem. And cocrete is stronger wehn slower setting. Water under the bridge. Just wipe the rock off, prime with oil or alcohol base and paint. And keep moving air and vent as much as possible. That's my two cents and worth about that much.


----------



## Tim0282 (Dec 11, 2007)

Some of your rock may be a little more prone to getting mold on it. Whether it was a little wetter than another sheet or whatever. But hard to believe the rock is the cause. The rock was just the bystander when the mold jumped on it. It's not the rock's fault. The rock is innocent. :no:

You can do a moisture test on your floor by using 6 mil plastic and taping it down to the concrete with duct tape and let it set a few days and see if any moisture is coming through the concrete and trapped below the plastic. Use about an eight foot square and tape the four sides down real tight. Watch the moisture gather...


----------



## BUTCHERMAN (Jan 19, 2008)

Does your sheetrock supplier store outside? It could have stored moisture at supply house and you installing in a barn with temp change day and night with out priming it for 4 months could be an issue. That could be why there is no consistent pattern. I would have recommended Dens armor or at least XP for this kind of project.


----------



## Frankawitz (Jun 17, 2006)

Sounds like condensation if the board was put up in Feb and the outside temp was colder then interior temp condensation will form on the backside of sheetrock where theres plastic or even House Wrap or roofing felt. mold can start forming within 24 to 48 hours and from the looks of those pictures its been going on for months and now with summer the mold is only going to grow faster. I would use a Mold Fogger and just rent the fogger for a week seal up all openings and let the fogger run.

Dude, Don't use bleach on mold all your doing is causing it to spread!!! Get Mold Control they sell it at Home Cheapo in paint dept. spray it down with this stuff. Good Luck


----------



## mbryan (Dec 6, 2010)

I realize this is a tad late but ill put in my .02.

In order to have mold growth you must have water, food and stagnant air. 

Food is anything cellulosic. It is easier for mold to digest processed wood, IE paper.
Stagnant air allows spores to "land" and start to colonize.
Water is any form of H2O.

If the drywall was fine 10 days ago and then bad today there had to be some sort of water intrusion. As it is just inside the structure something caused increased RH in the area. If it was wet from delivery or condensation from installation it would have shown up a couple weeks after installation. 

We see mold growth on a larger scale inside of walls than on the exterior due to airflow in the room that isn't present inside the cavities. It is common procedure to remove and replace any material affected by microbial growth. Some materials such as stud walls aren't logical to remove and can be cleaned, sanded and encapsulated. I would R/R the affected sheets.

I admit that my training may be outdated as it was a couple years ago but back then the theory was that mold is hydrophobic. When water, or chemical comes in contact with the colony it causes it to sporulate causing a dispersal of spores to ensure survival of the species. By spraying any product at the mold to kill it you are spreading it. It is best to vacuum the mold with a HEPA vac to remove as many spores as possible and then follow that with removal of the drywall, vac, sand and encapsulate the studs. Most people, especially in a garage, would just remove the drywall. 

Again, procedures may have changed in the last couple years but that is what would have been done last I knew.


----------



## Gillegit (Jul 22, 2011)

*Check for*

Sometimes pipes condensate and can cause that. Check to see if there are UN-INSULATED PIPES near the spot.


----------



## Gillegit (Jul 22, 2011)

*Wait a sec.*

That looks like a green house or some plants were grown in there. Spray BLEACH on the spots for a couple days. Don't soak it, but keep on it. after mold dies, primer with a shellac based primer.


----------

