How to get rid of mildew from drywall and floor from leaking furnace?

Question

I dont know how long our furnace has been leaking but there is standing water the floor of the small room its in and there is water damage on the bottom of the drywall on two wall of the room. On one side there is a green drywall sheet, it looks like the blackish mildew isnt bad on that side, you can just see where the water has been. On the back wall however the mildew is about a half an inch or so from the floor up the drywall (its regular drywall). On the floor of the room it looks mildewy is parts where the water was standing. The open wall, where there is on drywall and you can see the 2x4s there is no mildew at all on that wall or on the studs. I've sprayed bleach solution onto the drywall where the mildew is and on the floor. It looked like it did get some of it on the floor but didnt do much on the drywall.

We dont have the money to replace the drywall or the time to do it before the HVAC people come in and take out our old furnace and install the new one. So after that is done there will be no more leaking or standing water.

My question is, is it safe to not replace the drywall? The mildew will not grow or get worse anymore after the leaking stops right? How can I get rid of the mildew that is there? I dont know where the drain pipe is for the system, it looks like it leads to out side the house or something.

Answer 1

It sounds like you have taken care of the majority of the problem already.  A solution of 1 cup bleach to about a gallon of water is what is recommended.  As long as the mildew is not in the wood or insulation I think you have that covered.  As for the stain, the best way to get rid of that is to get a good anti mildew primer to cover the stain.  Kilz is one.  I would use the Kilz to prime the entire room.  

http://www.howtogetridofstuff.com/stain-...