How can I locate and deal with mold between floors?

Question

About 9 months ago, my wife and I replaced a toilet that had a broken wax ring. We got some water leaking down to the ceiling on the first floor. Now I'm having what seem to be mold symptoms -- I get runny eyes, have trouble breathing, and feel nauseous when I go into the bathroom. (I'm pretty sensitive to mold; my wife feels nothing).

I think that we probably have mold growing from the original leak, so I've opened a small hold in the celing underneath. What I see through the grate are some planks. They look like they were soaked through at one point but aren't wet right now. I'll try to get a picture and post it later. I don't see any mold at this point.

Anyone have any tips on how to procede? It's just a small hole right now, should I widen it? Should I cut through the mesh to get a better look? I'm going to hire someone to put the ceiling back on (time constraint). I assume it'll be a lot more expensive if they have to deal the mesh as well?

Any easy ways to tell if there's still some kind of leak going on? Any advise greatly appreciated! I do have a professional coming out, but he can't get here until next Wednesday and I'd like to resolve as much as I can quickly.

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Here's an update:

I think I'm seeing some black wood in there (need a better flashlight!).

Assuming I am, I guess my questions change to:

1. Is it o.k. to kill the mold by blasting ozone through a hole in the ceiling? I know this is generally not the recommended way to clean up mold; but I would do it by blasting for a limited time with no one in the house. I don't think there's anything between the floors I would need to worry about damaging?
2. I need to figure out if there's still a leak or some kind of humidity problem. Is it safe to assume that because the problem got worse there is? Should I try to find the pipes and see if they're leaking?
3. I would still like to hire someone to fix the plaster ceiling. Is it going to cost a huge amount extra if I cut through the mesh and they have to replace some of it? Does area make a massive difference in price for that kind of job? For what it's worth, I'm fine having drywall put up instead of plaster.

Answer 1

Mold goes away when the water goes away, so unless your toilet is leaking again, you have some other source of water or leak on the upper floor. This could be any number of things, even things not plumbing related, like water getting behind the siding, or a leaking roof with water running down the inside walls. As far as killing the mold that is there, I wouldn't waste my time. If you don't correct the water problem then the mold will return very shortly.

I need to figure out if there's still a leak or some kind of humidity problem. Is it safe to assume that because the problem got worse there is? Should I try to find the pipes and see if they're leaking?

Since you have had issues with the toilet in the past that would be the first area I would check. If the drain pipes for your upper floor are leaking then I would expect to see discoloration bleeding through the paint on the ceiling and the walls. If this turns up nothing then in the hole you have already cut, I would get a professional moisture detector device like the one a plumber would use.

These can help detect moisture and humidity in the air which can give you clues if you found the potential problem areas. Don't buy a cheap one because they don't work very well, I would instead see if a rental place will lend you a good one.

I think I'm seeing some black wood in there (need a better flashlight!).

This doesn't necessarily mean anything, it could be discoloration from previous water damage.

I would still like to hire someone to fix the plaster ceiling. Is it going to cost a huge amount extra if I cut through the mesh and they have to replace some of it? Does area make a massive difference in price for that kind of job? For what it's worth, I'm fine having drywall put up instead of plaster.

How big is the hole that you had cut? You can sometimes repair a hole by cutting a small piece of drywall and fitting that back in place, then using some thinset or spackle around the edges. Sand and repeat thinset or spackle two or three times until you have a smooth paintable surface.