Condensation behind shower inside interior wall

House Repair Talk

Help Support House Repair Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

sluder

Member
Joined
Aug 3, 2016
Messages
11
Reaction score
0
Our bathroom borders the hallway, a bedroom, the dining room, and an outside laundry room. The long side of the shower is against the dining room. The water controls are on the laundry room side and the hallway is against the other end of the shower.

We recently had a HVAC unit installed innour 1973 brick home. It never had one. We have now noticed our dining room and hallway paneling buckling. We tore it out to find condensation and mildew/mold growing? The plywood under the tub was wet as was the 2x4 studs. No insulation in interior walls but on the laundry room side there is pink/paper backed insulation. R19 I believe? 2×4 walls. Attic doesn't leak and nothing wet wet up there.

For a month orbso, we had some paneling and insulation out of the laundry wall to install a new tub drain. We are thinking the hot outside air came through this hole and under/around the shower causing it to condensate? 100 degree summer days. I put new insulation around plumbin and reinstalled laundry paneling. We put up clear plastic sheeting 1.5 mil where indoor paneling had been removed. Still much condensation on plastic.

We took plast c down and ran fans on wet wood under tub to dry everything out thinking that might be the cause. Haven't reinstalled plastic or paneling in hall or dining yet. I sprayed foam insulation around tub drain pipe to crawlspace. I put new insulation under floors near bathroom. No leaks under house.

New AC keeps house about 72 and there's a vent blowing near dining room wall. Another vent in bathroom. House is cold. Bathroom vent fan is.working.

Attic is insulated all over with blown in type. No gaps. Outdoor laundry room ceiling is seen in attic and it has dropdown ceiling with blown type on ceiling and pink Batts on side walls.

1. Any suggestions on cause or fix?

2. Should I insulate around shower before installing new hall and dining paneling? If so, what type and if paper backing which way should paper face?

My assumption was.

Plumbing work let air in wall and caused condensation. Then wood got wet so when wall put back, water trapped inside wall. Plastic sheeting sweating because water trapped in wall and cold AC blowing on plastic. Now that all is dry, should be ok to put paneling back with maybe insulation batts?

Any ideas anybody? I can compress pics and send if needed.
 
So does the tub have a tile tub surround and what are the tile stuck to visible from the other side. And any iof that appear or feel soft or wet?
 
Sorry for not mentioning. It's a full fiberglass shower/tub. No tile. Not leaking and no problem at sheet rock above and around shower walls.
 
Have you plugged the tub and filled it to the overflow pipe so that it overflows and checked for leaks.
Splash water at the shower controls and spout and check for leaks.
Check the caulking at the floor in front of the tub..
Hvac takes moisture out of the air so that would not be a cause, unless it is in the attic and the drain is leaking from that.
 
The bathroom floor is pretty new so the caulking looks good. I have not checked overflow but will. We only take showers but suppose water could get in there somehow. With laundry wall off I didn't see any leaks or water where handles and overflow come out.

What I mean by AC issue is that it blows on my dining room paneling which has no insulation in wall. I'm sure the thin paneling gets pretty cold compared to warm air that was blowing in through the outdoor laundry room and hitting the backsode of dining room paneling. This is where I had thought the condensation was happening on the inside wall on the back of the paneling. We did find a leaking tub drain pipe but it was under the house. The hole in the plywood under the tub where the drain pipe goes down was not sealed around the pipe so air and moisture was able to come up also. It has now been sealed and sprayed with expanding foam.

Not sure if this has been gradually happening over years or not but we just noticed it bad a couple months after new HVAC installed. I had assumed that maybe the laundry hole and gap under tub around drain could have started the problem but new AC unit made house colder which caused more condensation than wall could previously handle?

Let me clarify. The condensation is on the inside of the walls out of sight. There is no insulation in the interior wall between the back of the shower and the dining room wall. The paneling in the dining room got wet on the inside from condensation and eventually soaked through to the dining room where it became visible. The layers of the paneling started to separate which made it noticeable.

The only "hot hitting cold" that I could think of is cold dining paneling (visible) and hot air blowing from outside through gaps and hitting inside wall surface of same paneling. Thus condensation. The AC unit doesn't reach inside the walls so the dehumidifying action wouldn't apply. If the wall was sweating on the inddors/visible side of the paneling then I'd think it would be impacted by AC unit.
 
This is laundry room where the wall and insulation were removed for new drain install. You can see green fiberglass shower and how air could blow in and hit back of dining room wall
 
Interior blue walls are dining room and then hallway. All paneling was wet on the inside of wall.
 
We just had electrical panel completely replaced and moved to a different area. Not sure who thought it was a good idea to put water heater in front of panel. We've only moved into the house 2 years ago.
 
So just a thought but with AC, you do a better job of keeping door closed to the laundry room. No fresh air vent in laundry room, so when dryer is running it is or was sucking warm moist air up under tub and into that room.
Dropping moisture off as it went by.
 
try this, you said the air was blowing on he paneling causeing it to buckle.

turn the register around.

where do you live ? what state not your address,

do you have an air conditioner installed or a swamp cooler installed ?

sounds like you need a dehumidifier
 
We just had electrical panel completely replaced and moved to a different area. Not sure who thought it was a good idea to put water heater in front of panel. We've only moved into the house 2 years ago.

NOTHING is supposed to be in front of an electrical panel for 5 feet

i could be mistaken on the correct number of feet, maybe 4 or 6, i like the number 5:hide:
 
Last edited:
NOTHING is supposed to be in front of an electrical panel for 5 feet

i could be mistaken on the correct number of feet, maybe 4 or 6, i like the number 5:hide:

5 is nice..but 3 is the number....the Intimidator, see, easy to remember:rofl:
 
Our bathroom borders the hallway, a bedroom, the dining room, and an outside laundry room. The long side of the shower is against the dining room. The water controls are on the laundry room side and the hallway is against the other end of the shower.

We recently had a HVAC unit installed innour 1973 brick home. It never had one. We have now noticed our dining room and hallway paneling buckling. We tore it out to find condensation and mildew/mold growing? The plywood under the tub was wet as was the 2x4 studs. No insulation in interior walls but on the laundry room side there is pink/paper backed insulation. R19 I believe? 2×4 walls. Attic doesn't leak and nothing wet wet up there.

For a month orbso, we had some paneling and insulation out of the laundry wall to install a new tub drain. We are thinking the hot outside air came through this hole and under/around the shower causing it to condensate? 100 degree summer days. I put new insulation around plumbin and reinstalled laundry paneling. We put up clear plastic sheeting 1.5 mil where indoor paneling had been removed. Still much condensation on plastic.

We took plast c down and ran fans on wet wood under tub to dry everything out thinking that might be the cause. Haven't reinstalled plastic or paneling in hall or dining yet. I sprayed foam insulation around tub drain pipe to crawlspace. I put new insulation under floors near bathroom. No leaks under house.

New AC keeps house about 72 and there's a vent blowing near dining room wall. Another vent in bathroom. House is cold. Bathroom vent fan is.working.

Attic is insulated all over with blown in type. No gaps. Outdoor laundry room ceiling is seen in attic and it has dropdown ceiling with blown type on ceiling and pink Batts on side walls.

1. Any suggestions on cause or fix?

2. Should I insulate around shower before installing new hall and dining paneling? If so, what type and if paper backing which way should paper face?

My assumption was.

Plumbing work let air in wall and caused condensation. Then wood got wet so when wall put back, water trapped inside wall. Plastic sheeting sweating because water trapped in wall and cold AC blowing on plastic. Now that all is dry, should be ok to put paneling back with maybe insulation batts?

Any ideas anybody? I can compress pics and send if needed.
Has anyone every
Our bathroom borders the hallway, a bedroom, the dining room, and an outside laundry room. The long side of the shower is against the dining room. The water controls are on the laundry room side and the hallway is against the other end of the shower.

We recently had a HVAC unit installed innour 1973 brick home. It never had one. We have now noticed our dining room and hallway paneling buckling. We tore it out to find condensation and mildew/mold growing? The plywood under the tub was wet as was the 2x4 studs. No insulation in interior walls but on the laundry room side there is pink/paper backed insulation. R19 I believe? 2×4 walls. Attic doesn't leak and nothing wet wet up there.

For a month orbso, we had some paneling and insulation out of the laundry wall to install a new tub drain. We are thinking the hot outside air came through this hole and under/around the shower causing it to condensate? 100 degree summer days. I put new insulation around plumbin and reinstalled laundry paneling. We put up clear plastic sheeting 1.5 mil where indoor paneling had been removed. Still much condensation on plastic.

We took plast c down and ran fans on wet wood under tub to dry everything out thinking that might be the cause. Haven't reinstalled plastic or paneling in hall or dining yet. I sprayed foam insulation around tub drain pipe to crawlspace. I put new insulation under floors near bathroom. No leaks under house.

New AC keeps house about 72 and there's a vent blowing near dining room wall. Another vent in bathroom. House is cold. Bathroom vent fan is.working.

Attic is insulated all over with blown in type. No gaps. Outdoor laundry room ceiling is seen in attic and it has dropdown ceiling with blown type on ceiling and pink Batts on side walls.

1. Any suggestions on cause or fix?

2. Should I insulate around shower before installing new hall and dining paneling? If so, what type and if paper backing which way should paper face?

My assumption was.

Plumbing work let air in wall and caused condensation. Then wood got wet so when wall put back, water trapped inside wall. Plastic sheeting sweating because water trapped in wall and cold AC blowing on plastic. Now that all is dry, should be ok to put paneling back with maybe insulation batts?

Any ideas anybody? I can compress pics and send if needed.
how did you fix this? We are having the same issue after adding a new window unit so the rooms are cooler than inside the wall hence the condensation. Help!!!
 

Latest posts

Back
Top