Mildew/Moldy Smell

[matthewstimp]

Hi everyone,

At the first of this week we noticed a fairly strong mildew/moldy smell in my son's room.  After some sniffing around, I determined the smell was entering the room at a phone jack.  Then a few day's later, we began to occasionally notice the smell in the kitchen, and it seems to be coming from the same wall (son's room is directly above it).  Our house is a colonial, and this particular wall is an interior wall running perpendicular to the back of the house.  The only water supply that I think is in this wall would be the line for the icemaker.  There is no indication of any water damage or leaks anywhere.   What windows may allow water into this area all look to be in good shape.  

The house sits on a crawl space, and I am wondering if my problem is in the crawl space and if, for whatever reason, the odor is working its way up into the house through this particular wall...path of least resistance perhaps.  I looked under the house quickly this morning and all looks dry.  After work today, I will crawl all the way under and fully inspect.  A couple of points:

1. We have had a ton of rain in the past two weeks and a fairly wet summer. 
2. There is a moisture barrier in the crawl space, but it is only on the floor, not up the walls or supports. 
3. The smell is only noticeable in the evening.  This morning, no noticeable odor in his room or the kitchen, and this has been consistent all week.  

I put my outdoor thermometer, which also measures relative humidity, under the house this morning.  Right now, relative humidity is 92% and it is 73 degrees.  I have done some preliminary reading, and it seems like sealing the crawl space and putting in a dehumidifier is how to prevent mildew mold under there, if that is the problem. 

During my visual inspection this evening, aside from the obvious signs of mold/mildew/dampness/stuff being wet, what else should I be looking for?  Let's say I get under there and everything looks to be ok, what's the next step?  Open up that wall and see if there is moisture?   

Thanks,
Matt

[Cooler]

Or it could be small rodents that died in the wall space.  If the smell is persistent, then I think you have to open the wall.

They do sell mold test kits and that might give you an indication on which way to go.

I saw them at Lowes for about $10.00.  I don't know how reliable the results are though.

You can hire an inspector to determine the problem.  And that might make more sense then tearing open the walls and finding nothing.

[matthewstimp]

Or it could be small rodents that died in the wall space.  If the smell is persistent, then I think you have to open the wall.

They do sell mold test kits and that might give you an indication on which way to go.

I saw them at Lowes for about $10.00.  I don't know how reliable the results are though.

You can hire an inspector to determine the problem.  And that might make more sense then tearing open the walls and finding nothing.

I have thought about something related to a dead animal...the inspector is a good idea.  Do you think any home inspector (who is worth their salt) would be able to handle this?

I really do not want to have to open this wall up...

Matt

[Roly]

Does the crawl space smell moldy ?   Try placing a fan to move fresh dry air into the crawl space during the day and see if that helps.  Roly

[matthewstimp]

Does the crawl space smell moldy ?   Try placing a fan to move fresh dry air into the crawl space during the day and see if that helps.  Roly

I just spent about a half hour down in the crawl space crawl through the entire thing, and I am pretty sure that is not the problem.  Crawl space smells fine and everything looks fantastic.  

I am not sure where that leaves me now....on one hand, I did not want a mold problem down there.  On the other hand, I am not sure what the next logical step would be, sans a sledge hammer into that wall. 

Matt

[daddo]

I hate that. This old house delivers smells easily. Once it was under the kitchen sink area, then a leak behind the fridge, an occasional dead animal and so on. The last one ended up being someone threw a tuna can in the trash instead of the separate bag- I searched all over for that one.



  If you suspect there is wetness from rain or pipes, a IR camera might find the wet spot on walls or the ceiling or floor. I might even start in the attic and looks for rain stains or spots. Since it is coming from an outlet, I suspect from under the house, especially if the wiring is run under there- you could caulk the wiring holes closed. Instead of sealing the under space, using more ventilation might be better.

[jteneyck]

If the crawl space is dry and you didn't see any black mold then the problem must be coming from elsewhere, unless there is a dead animal in the crawlspace you didn't see, but that's unlikely.  You mentioned the icemaker water line being in the wall where the smell is coming from.  I would turn off the supply to that line and see if the smell goes away.  If it does you'll have your answer and can then figure out how to replace that line.  If it's not the water line then you likely have a dead rodent or another source of water getting into the wall.  Have you inspected your roof and gutters?  Any vent pipes that might be blocked? 

FWIW, we had the most foul smell in our basement a few years ago.  After a week of checking things I found a putrid bag of green beans my wife had taken out of the freezer and then put on top of the freezer while she looked for something else, then forgot about.   

John

[woodgrain]

Hi everyone,

At the first of this week we noticed a fairly strong mildew/moldy smell in my son's room.  After some sniffing around, I determined the smell was entering the room at a phone jack.  Then a few day's later, we began to occasionally notice the smell in the kitchen, and it seems to be coming from the same wall (son's room is directly above it).  Our house is a colonial, and this particular wall is an interior wall running perpendicular to the back of the house.  The only water supply that I think is in this wall would be the line for the icemaker.  There is no indication of any water damage or leaks anywhere.   What windows may allow water into this area all look to be in good shape.  

The house sits on a crawl space, and I am wondering if my problem is in the crawl space and if, for whatever reason, the odor is working its way up into the house through this particular wall...path of least resistance perhaps.  I looked under the house quickly this morning and all looks dry.  After work today, I will crawl all the way under and fully inspect.  A couple of points:

1. We have had a ton of rain in the past two weeks and a fairly wet summer. 
2. There is a moisture barrier in the crawl space, but it is only on the floor, not up the walls or supports. 
3. The smell is only noticeable in the evening.  This morning, no noticeable odor in his room or the kitchen, and this has been consistent all week.  

I put my outdoor thermometer, which also measures relative humidity, under the house this morning.  Right now, relative humidity is 92% and it is 73 degrees.  I have done some preliminary reading, and it seems like sealing the crawl space and putting in a dehumidifier is how to prevent mildew mold under there, if that is the problem. 

During my visual inspection this evening, aside from the obvious signs of mold/mildew/dampness/stuff being wet, what else should I be looking for?  Let's say I get under there and everything looks to be ok, what's the next step?  Open up that wall and see if there is moisture?   

Thanks,
Matt

Is there a plumbing vent in the wall? if so, maybe there is a leak in the roof jack.

Or - Have you made any 'efficiency' changes to the home in the last couple of years?  - Sometimes when people add insulation or air seal the exterior walls the result can be condensation in unusual places - There are barometric pressure differentials between conditioned spaces and unconditioned.  Those pressures natural want to equalize and when concentrated, create airflow's in other walls and sometime can result in condensation.  It's a little like Bernoulli's Principle.  

https://en.wikipedia.org/wiki/Bernoulli%27s_principle

[matthewstimp]

I just spent about a half hour down in the crawl space crawl through the entire thing, and I am pretty sure that is not the problem.  Crawl space smells fine and everything looks fantastic.  

I am not sure where that leaves me now....on one hand, I did not want a mold problem down there.  On the other hand, I am not sure what the next logical step would be, sans a sledge hammer into that wall. 

Matt

I'm leaning towards dead animal up in the attic type area.  Our third floor is finished, and the HVAC equipment is shoved back in the eves.  I opened up the half door leading to that equipment, which is directly over my son's room, and got blasted in the face with the odor.  The problem is there is so much equipment shoved back in there, I am not real sure how I can get back behind it to look around.  

Matt

[Snipe Hunter]

Are your gutters clean?
A lot of the water damage and mold I find in houses is from clogged gutters. That and leaking faucets and toilets.