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First time house owner Mold questions.

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Hi folks new guy here. I bought a well kept house by an older couple.
I took off the carpet and the wallpaper in the bedroom to repaint and do hardwood floor.
Looks like back in the day the window leaked, there is some water damage on the floorboards? (baseboards the stuff that you put the carpet on) and some solid black spots below the window sill that it looks like have been worked on and painted over.

Now it has been raining here pretty good and both the floor board and the window sill are VERY dry so it looks like they addressed the problem.

Now I poked the drywall below the window sill and it looks a bit flaky and I am concerned about the black spots. Like I said the black spots look like they were worked on painted over there is some spackle on top of them.


Wondering what I should do? Is the mold dead? Or should I rip out the wall below the window?

Will try to get some pictures.
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...I poked the drywall below the window sill and it looks a bit flaky
Wondering what I should do?
Flaky is better than mushy.

Is the wall plaster? Like when painting... pick at it until it isn't flaky. Then fix.
If the wall is GWB (rather than plaster) cut out that section. Then replace.

Do the same with those "black spots look like they were worked on painted over".
Mold doesn't die unless it's been treated with a fungicide. If it dries, it goes dormant until the next moisture event. If it was covered over with wallpaper then it was in an ideal environment to thrive. Wallpaper paste is gourmet mold food. If the wall is solid, then scrub the mold off of it with a cleanser, treat the area with a fungicide, let it dry and then seal it with something Zinssers or Kilz. If the wall is already soft from previous moisture events, then replace the drywall. I am assuming that the area is confined to just under the window, and that it is relatively small. If it is one huge black mold colony, then replace the drywall. It is not uncommon to find mold in these areas. One soaking rain blowing into a window left open would be enough for a mold colony to get established under wallpaper.
Avoid breathing any dust from the stuff. You're at a window, put a fan in it and suck any dust and mold fragments/spores out while you work there. Clean the mold up. Don't just treat it and cover it. Sounds like the last person did that....... or less. If you treat it with a bleach solution, use 10%, no more and keep the fan running while you do. After it dries, then seal it. This will lock down any stray fragments or spores. :thumbsup:
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It is not soft and mushy just flaky I pulled the wallpaper off and will be painting the wall. That is the thing guys, it is not on the surface of the drywall it more like discoloration but like I said it was wallpapered over.
...it is not on the surface of the drywall it more like discoloration
but like I said it was wallpapered over.
There are a lot of "The Dread Pirate Mold" warnings out there.
Some are actually valid.
If the wall is solid, then I wouldn't get too carried away. Seal it with Kilz and paint it. If it had been overly wet the drywall would have fallen apart. If it was a big mass of mold, my strategy would be different.
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My concern is not so much the surface mold, but whether the insulation inside the wall got wet. Fiberglass insulation acts like a sponge and just holds the water. That in turn keeps the wood studs wet which will rot them and allow mold to grow. I had to replace the entire front of my house due to faulty windows leaking water into the stud cavities. The studs were mush when it was opened. Luckily the mold wasn't too bad, but the damage to the studs was horrendous.

If you can, at least pop off the window casing trim at the bottom of the window to assess whether it is truly dry. If you can get your hands on a moisture meter, a quick poke through the drywall (the leads are about as thick as a finishing nail depending on the model) can also truly assess if the insulation got wet (if there is any insulation :p ).
A few small steps for a little piece of mind.
My concern is not so much the surface mold, but whether the insulation inside the wall got wet. Fiberglass insulation acts like a sponge and just holds the water. That in turn keeps the wood studs wet which will rot them and allow mold to grow.
A few small steps for a little piece of mind.
Wrongo that is wrong information. Fiber glass insulation is not absorbent and, if exposed to moisture, will not wick up or hold water. It will dry out and retain its original R-value. Why? It is glass other wise we would not use glass jars and drinking glasses. Cellulose fiber insulation holds water big time!
Wrongo that is wrong information. Fiber glass insulation is not absorbent and, if exposed to moisture, will not wick up or hold water. It will dry out and retain its original R-value. Why? It is glass other wise we would not use glass jars and drinking glasses. Cellulose fiber insulation holds water big time!
Well I wish you would have explained that to the insulation in the front of my house. It was weeks since the last rain and the insulation removed was still soaked through to where it was dripping wet.
Wrongo that is wrong information. Fiber glass insulation is not absorbent and, if exposed to moisture, will not wick up or hold water. It will dry out and retain its original R-value. Why? It is glass other wise we would not use glass jars and drinking glasses. Cellulose fiber insulation holds water big time!
That is absolutely wrong. Fiberglass insulation will hold water like a sponge. Worse yet it WILL NOT dry out, but will hold water and damage adjacent materials. Oh and glass jars and drinking glasses hold water too!! :thumbsup:
That is absolutely wrong. Fiberglass insulation will hold water like a sponge. Worse yet it WILL NOT dry out, but will hold water and damage adjacent materials. Oh and glass jars and drinking glasses hold water too!! :thumbsup:
How can glass hold water or as you put it absorb water? hmm? I bet if he had cellulose in his walls it would "never absorbed any water" <sarcasm>off. so if the water had a place to go which it did not because if it had your water damage would have been small. make a air tight home you also make a water tight one too at the same time. just a fact of nature and laws of physics. Also be cause of the way the fibers of FG batts that help it trap air it also traps water. in order to have batts dry out they have to be exposed to air movement. and just FYI all wood has mold spores on it the first place the mold just needs a dark wet enviroment for it to grown. and using kitcjen bleach will not kill mold on porous surfaces like wood or dry wall. so if your worried about mold tear it out and replace it. open it up to the air and light. use things like Tea tree oil or hydrogen peroxide to kill mold.
Thank You. I think you made my point.

"Also be cause of the way the fibers of FG batts that help it trap air it also traps water. in order to have batts dry out they have to be exposed to air movement." And yes, cellulose fibers will absorb and hold water. <no sarcasm>

"and just FYI all wood has mold spores on it the first place the mold just needs a dark wet enviroment for it to grown. and using kitcjen bleach will not kill mold on porous surfaces like wood or dry wall."

I think it might be best if you studied up on mold before you boldly post things as fact.

Fact: common molds that thrive on building products require three things to thrive: temperatures in the 40-110 degree range, an organic food source and moisture of 60%RH or .6 water content and up. Mold will not thrive in overly wetted conditions. Generally, mold does not care about light or dark. Dark areas tend to have little air movement and as such tend to remain damp. Mold spores exist everywhere, including that loaf of bread on your kitchen counter. No product is completely effective at killing embedded mold in porous surfaces, bleach will kill mold on surfaces.

Finally, mold does not thrive on the glass fibers in fiberglass insulation, but will love the trapped organics and moisture.
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yes those links are in deed handy. just some fyi reading them the first one is if the insulation stays wet becomes wet and is not alowed to dry out it loses its R value. also stated in the first link, yes took time to read it wet spray cellulose may take any were from 36 hours to one year to dry out. Before it is safe to cover.
second Mold spores are every were yes you can find them in fiberglass and find them in cellulose too. when wet and even your second post states it can not prove that the mold was growing on the fiber glass just that it was in the batt.
what is not said is when cellulose becomes wet it is a food source for mold. even with the borite salts. so bottom line keep your home dry! and if you have worries about what type of insulation use foam.
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Well I used the mold killer spray and the black stuff came off. Cut off the front portion of the dry wall (paper and some plaster) from under the window and it was clean and white. So I am ASSuming here it was just some stuff formed between the old wallpaper.

Oh and some pictures as promised:


stripped the carpet and sandpapered all the walls to get most of the wallpaper glue off


Next step is LOTS of skimming (At least that is what I think it is called)
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I would assume the same as you. With wallpaper in this location, some mold would not be unusual. As a final step, coat the area with a sealer as I mentioned above. Unless you go back again with wallpaper, I doubt you'll see another mold event.
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