ODD water damage to sheetrock?
#1
Senior Member

Thread Starter

Son's tenants sent a photo and I'm needing help with a diagnosis. Townhouse is 20 years old, tile shower in the MBA is above that closet. What's confusing to me is that I've never seen dripping water do anything but create a stain that gets larger and larger, but stays contiguous and circular. These mildew spots just don't look like leaking water.
I told him to Sawzall a 2x2 foot section and the answer will be clear if it's a drip, and hope he doesn't find a mouse house on that section, but what do you guys see from the photo?

I told him to Sawzall a 2x2 foot section and the answer will be clear if it's a drip, and hope he doesn't find a mouse house on that section, but what do you guys see from the photo?

#2
Senior Member

Wear a respirator....that's some serious mold.
A slow drip over months and months
A slow drip over months and months
#3
Senior Member

One of our condos had a leak in the bathroom from the bathroom in the unit above. The ceiling drywall never showed mold but it got so waterlogged that it started to bulge downward. Somebody reached up and touched the bulge and it let go. what a mess. No obvious sign until the drywall bulged.
#5
Junior Member

If thats under the shower assuming cast tub with tile up walls. You have a drain pipe or seal leaking, bad caulk or grout joint or if it has a window or ledge you may have a tile job going bad.
Spray with bleach or peroxide 15 minutes or so before tearing out will help keep the mold spores down..
Spray with bleach or peroxide 15 minutes or so before tearing out will help keep the mold spores down..
Last edited by fishnfool38; 11-19-2020 at 05:26 AM.
#7
Senior Member

Thread Starter

I read that there are 20,000 kinds of mold, and the black mold from that Texas house isn't everywhere so seeing dark moldy spots doesn't necessarily create a giant hazard. However, convenient that the covid mask will actually serve a purpose during this tearout.
Assuming that it's a drip, what would cause the many small circles, rather than one larger one?
Assuming that it's a drip, what would cause the many small circles, rather than one larger one?
#9
Admirals Club 


Directly under a bathroom with that much mold but no Sheetrock damage it’s either a very slow leak or shower is used infrequently.
Another option is a un-insulated HVAC duct dropping condensation onto the Sheetrock, but most likely there would be signs in a few different areas.
Another option is a un-insulated HVAC duct dropping condensation onto the Sheetrock, but most likely there would be signs in a few different areas.
#11
Admirals Club 


Just re read. Please do not have him use a sawzall to open up the wall. Multi tool with a bi metal blade msking sure you only cut 3/4” deep while holding a vac next to it would be the best method.
#12
Senior Member

Thread Starter

Since it's the MBA, I'd think that the shower is used daily, and a slow leak with PVC drains would be possible, but why drip in different spots? That doesn't add up.
The home is in Birmingham (temperate climate), and the closet is 15' away from an exterior wall, but worth noting for him to use a short blade on the sawzall.
The home is in Birmingham (temperate climate), and the closet is 15' away from an exterior wall, but worth noting for him to use a short blade on the sawzall.
#13
Senior Member

Thread Starter

#14
Senior Member


id say its an intermitten leak vs a constant leak. allowing the sheet rock to slowly absorb and semi dry until the next episode of leaking. like a drain. thats why your getting the odd stains and symptoms.
#15

that could easily be from a shower leak, especially if there is insulation on top of that sheetrock. that doesn't look like a very large area to me, i'd say its been dripping for awhile and caused the surrounding sheetrock to get wet.
#17
Senior Member

Thread Starter

Good idea. Maybe the first step is to remove the shower's drain grate and inspect for failed caulk around the drain. Good idea.
IF he sees failed caulk, can it be repaired from above, or will the drain need dis-connecting from below in order to do the job?
#19
Admirals Club 


Looks like a slow drain drip; maybe from an upper floor bathroom leak or AC condensate drain. Be ready for a good size mold mitigation. It also may be covered under insurance?
#20
Senior Member

Thread Starter