Removing mold from the back of drywall

[Sam Alex]

Hello,

I have read you should replace drywall if mold gets on it however I'm in a tough spot. I have 2 full bathrooms back to back. I am remodeling one of them and behind the shower I found mold on the back of the drywall in the other bathroom (see picture). I plan to re-do the other bathroom (the one with mold on the back of the drywall) later this year. Is there a good way to remove the mold that is currently there without replacing it right now? I don't want to have both of my full bathrooms out of commission so I can't just cut the drywall out right now. I was going to re-dry wall the one I'm working on now (with green drywall) and get to the other one later. I don't want the current mold to somehow get on the new drywall im putting up though. BTW it appears the original shower had leaked and thats what had caused that mold spot. The previous owner put in a new shower to fix that leaking problem, it doesn't appear the mold is growing or anything.

Thanks in advance,
Sam

[Steven Turetsky]

If that was my house I would not be building a shower stall using gypsum board... regardless of the color.

[John Kogel]

Can you post a bigger picture for my library? Lay it sideways, 800 X 600. ;)

[Sam Alex]

If that was my house I would not be building a shower stall using gypsum board... regardless of the color.


Well I plan on buying a shower that comes in 3 pieces (3 walls) and putting a mold resistant drywall up in the rest of the bathroom. I just don't want to cover up that mold if there is a way to remove it now. Eventually when I refinish that bathroom all the drywall will be removed.

[Billy Stephens]

Can you post a bigger picture for my library? Lay it sideways, 800 X 600. ;)

Enjoy !

[Jeff Langhorn]

Cleaning the mold off the surfaces would be temporary. What needs to be addressed is the moisture causing the problem. If the mold is a concern then plan on replacing both showers surrounds now.
Jeff

[Jeff Langhorn]

Hello,

I have read you should replace drywall if mold gets on it however I'm in a tough spot. I have 2 full bathrooms back to back. I am remodeling one of them and behind the shower I found mold on the back of the drywall in the other bathroom (see picture). I plan to re-do the other bathroom (the one with mold on the back of the drywall) later this year. Is there a good way to remove the mold that is currently there without replacing it right now? I don't want to have both of my full bathrooms out of commission so I can't just cut the drywall out right now. I was going to re-dry wall the one I'm working on now (with green drywall) and get to the other one later. I don't want the current mold to somehow get on the new drywall im putting up though. BTW it appears the original shower had leaked and thats what had caused that mold spot. The previous owner put in a new shower to fix that leaking problem, it doesn't appear the mold is growing or anything.

Thanks in advance,
Sam

What may surprise many, a lot of houses built pre 80's with tile shower walls look like that behind the walls.
Jeff

[John Kogel]

Sam, that mould is all the way through the gypsum. It can't be washed off. Slap a coat of paint on it if you feel the need. Even if you removed it all, you could still get mold in your new walls from spores in the air. The spores won't grow if you keep the wallboard dry, that is the key.

Billy did I ask for a pdf? Or do you just think I should have one? How about an Elvis impersonation, can you do that for us? :D

[Jerry Peck]

That was caused by the packing on the cold water tub valve leaking, possibly some from the hot water valve also, but probably all from the cold water valve.

That leak was long term too.

[Lon Henderson]

Others have touched on this, but I'll try to put it into one post. Inspect with a probe (screwdriver, etc) the framing for wood rot. If found, the affected framing must be replaced. One problem for you, is that it can be difficult to inspect the surface of the studs that is against the backside of the drywall that is on the other bath. There might be early rot there. When you get around to remodeling that bath, you might discover that early rot and now you are in a pickle having to replace the framing after you've remodeled the first bath. If possible, you'll be better off doing both baths now.

If your framing is still solid and the mold is just on the surface, then you can clean it up with a good disinfectant type cleaner. Of course, everyone loves bleach, but there are other effective products that aren't as harsh. Read the labels on what they can do.

Never use any kind of gypsum drywall for around the tub or shower. That includes "green board". Use only concrete super board type material. Do it right while you have it all opened up.

[Billy Stephens]

think I should have one? How about an Elvis impersonation, can you do that for us? :D

Well you do need Help !
( if you weren't so far away I'd be Glad to Give You One, or Two.)

[Ted Menelly]

The first thing I ever did for work was hang drywall. It went from mortar/concrete over mesh to regular drywall behind tile to green board behind tile to concrete board behind tile. I could not even tell you the amount of jobs we did decades ago with green board in entire shower rooms in facilities etc to homes.

Anyway, washed it down with a bleach solution, temporary but it will work. At least fix the leaks before you close it all up. It will be fine as long as you get back to it in not that long a period of time. At least now you know why you and the family have had some respiratory problems:confused:

[Robert Sole]

If the framing is rotted out, you will need to do something very quickly but if not, there are anti fungal chemicals available that my help at least for a while. Try calling acommercial cleaning products store to see if they carry them.

Even if they do, I would not want to leave it that way for long.

[Ronin Kossow]

Hello,

I have read you should replace drywall if mold gets on it however I'm in a tough spot. I have 2 full bathrooms back to back. I am remodeling one of them and behind the shower I found mold on the back of the drywall in the other bathroom (see picture). I plan to re-do the other bathroom (the one with mold on the back of the drywall) later this year. Is there a good way to remove the mold that is currently there without replacing it right now? I don't want to have both of my full bathrooms out of commission so I can't just cut the drywall out right now. I was going to re-dry wall the one I'm working on now (with green drywall) and get to the other one later. I don't want the current mold to somehow get on the new drywall im putting up though. BTW it appears the original shower had leaked and thats what had caused that mold spot. The previous owner put in a new shower to fix that leaking problem, it doesn't appear the mold is growing or anything.

Thanks in advance,
Sam


You need to scrub with a mild cleaning solution or bleach solution to clean surface mold off. This will only clean surface. Bleach is not a recommended cleaning agent. I have found it works well if scrubbing thick surface mold. Remember it is corrosive to any metals. I use a product called "Anabec" www.anabec.com/ it is a microbial cleaner and inhibiter. You have to spray the cleaner then the inhibiter afterwards. I use a paint sprayer for large jobs and a pump can for small jobs. This is really all that has to be done without the scrubbing but sometimes it is easier to scrub than to explain why the mold is still visible. Although the mold is dead throughout it is visible. There are schools and hospitals that use this product. I noticed that HD sells a microbial cleaner but have never used the product.

Robin Kossow
Oviedo, Florida
Weston Rehab and Construction Management
Florida license contractor CBC 052252
Florida home inspector HI 2666

[Raymond Wand]

Mould (Mold) Remediation (http://www.forensic-applications.com/moulds/remediation.html)

[Sam Alex]

I ended up using a mild bleach mix to clean the wood and back of the drywall. When this was finished I used a mold inhibiter spray. Turns out the mold was only on the drywall paper and not the actual drywall (see picture). There was also no wood rot. Hopefully this will be good enough until I finish the other bathroom.

[Ronald Bloss]

Since you have wall open alreday, why not replace the moldy sheetrock. If you leave or try cleaning
the mold is just going to spread it and it will coame back and make you and your family even pet sick.

ron

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Since you have wall open alreday, why not replace the moldy sheetrock. If you leave or try cleaning
the mold is just going to spread it and it will coame back and make you and your family even pet sick.

ron

[Darrel Hood]

Since, in your original post, you did not mention any ill health effects, it's not a big deal for the short term. If you want to clean it, I suggest the method that includes the inhibiter. I would also spray the inhibiter on all studs in my current project and on the back of the wall covering material. Then when you rework the second shower, use the inhibiter freely.