musty smell in basement

[RT]

Hi,

My house is 6 years old and my basement (unfinished) started smelling since this summer. Whenever I go to basement I start to have runny nose and sneezing. But it goes off after taking some antihistamine. I cleaned my entire basement, disposed tons of boxes and pressure washed it. Opened the windows for almost a week and ran the dehumidifier for a week (closed the windows during running the humidifier). I visually inspected the basement and I don't see any presence of mold. But I still sneeze and runny nose whenever I go to my basement and the smell is there. But I do see which looks like white powder (Efflorescence??) on the floor and it mostly appears around the cracks of the floor and towards the edge of the house along the bottom of the frame. No dampness on the walls. Its a concrete poured walls and floor.

Any help is highly appreciated.

Thanks, Ramesh

[Joe]

Are you downhill from any nearby septic tanks?

Joe

[RT]

No septic tanks. We have county provided sewage system which we pay for it every month (a lot).

-RT

[ransley]

Your nose doesnt lie, you have mold somewhere. The white you see could be mold. ive seen white mold but usualy on leather. Laundry bleach kills it, I dont know how much to dilute it since I usualy use it outside full strength but im guessing you are closed up for the winter so it will smell for days like bleach. I use a garden sprayer to get it on all surfaces fast. How about the basement ceiling and anything dark looking on walls could be mold. If you use bleach and it looks cleaner in a few minutes its because you just killed mold that made it look dirty.

[RicodJour]

The white stuff is probably efflorescence. If you have efflorescence you have water issues. There will not necessarily be obvious wet spots or staining. Post some pictures to a hosting site and post the link back here so we can see what's what.

Do the old plastic bag test. Tape down a plastic garbage bag to the floor over some of that efflorescence. Let it sit for a day or two, then remove the bag and observe. You will know if you have water coming up through the slab and evaporating.

Filling the cracks and sealing the floor should take care of a minimal water problem. If it's more than that you might have to do more work to take care of it.

R

[hrhofmann]

What changed this year compared to the previous 5 years??? It could be several blocks away even.

Where I live, in the far western Chicago suburbs, they put in new storm sewers in an area 2000 feet away from where I live that did not have storm sewers previously. It changed the groundwater pattern, and my sump pump has not run since they did that whereas it ran at least once an hour before they put the storm sewers in.

[RT]

Yes, the white powdery stuff is efflorescence. It is appearing only on the floor towards the frame of the house. I have uploaded some pics:

Is there a allergy reaction to efflorescence? I checked the humidity using hygrometer and it is 48%. My rest of the basement looks very clean except couple of cracks.

I will do the plastic bag test and post the result soon.

Any help is highly appreciated.

-RT

[RT]

Yes, the white powdery stuff is efflorescence. It is appearing only on the floor towards the frame of the house. I have uploaded some pics:

Is there a allergy reaction to efflorescence? I checked the humidity using hygrometer and it is 48%. My rest of the basement looks very clean except couple of cracks.

I will do the plastic bag test and post the result soon.

Any help is highly appreciated.

-RT

[RicodJour]

You can see the evidence of moisture - even without the efflorescence. You almost assuredly have a "situation" behind the plastic vapor barrier. The perimeter drainage and foundation waterproofing are not doing the job.

Check to see if there's a correlation between the gutter downspouts and the location of the leaks. That's the first place to look. Next check that soil around the house is pitched away from the house. There should never be any water flowing back towards the concrete foundation.

I am not aware of any allergic reaction to the minerals that are leaching out of the concrete - that is what efflorescence is - but I think that is doubtful. More likely the vapor barrier is trapping water against the foundation and mold is growing in there. Slice a section of the vapor barrier with a knife near a spot with efflorescence and I would bet you'll get a strong mold smell.

R

[RT]

I just put the plastic vapor barrier couple of weeks before. I have been having this allergy reaction since 4-5 months. It took me while to realize that whenever I go to the basement I get the allergy reaction. Like you said there is a corner where I see water from downspouts are accumulating towards the basement wall (picture 1). I extended the water spout to 5 feet and now there is no water accumulated towards the basement wall.

Before putting the vapor barrier I checked through out the basement to make sure there is no mold build up and everything looks pretty clean. It started with musty smell. Now the smell is going away little bit. May be due to the winter weather. I am unsure what is causing my allergic reaction since there is no visible mold.

-Ramesh

[RT]

I just put the plastic vapor barrier couple of weeks before. I have been having this allergy reaction since 4-5 months. It took me while to realize that whenever I go to the basement I get the allergy reaction. Like you said there is a corner where I see water from downspouts are accumulating towards the basement wall (picture 1). I extended the water spout to 5 feet and now there is no water accumulated towards the basement wall.

Before putting the vapor barrier I checked through out the basement to make sure there is no mold build up and everything looks pretty clean. It started with musty smell. Now the smell is going away little bit. May be due to the winter weather. I am unsure what is causing my allergic reaction since there is no visible mold.

-RT

[Stormin Mormon]

Sounds like some kind of mold or mildew. I'd want to spray everything with dilluted Clorox, and try to kill it off. A good idea to wear a face mask or respirator. Some organisms like that can make you sick.

A friend of mine developed a nearly fatal double pneumonia from cleaning out a trailer that was loaded with mold. Changed his life forever, and not for the good.

[willshak]

Too late to check now, but there should be a vapor barrier over the substrate before the floor is poured. Additionally, the outside of the concrete walls should have a vapor barrier to prevent ground water from seeping through the wall. The outside of my 1984 concrete walls were tarred and plastic sheeting stuck to the tar. Now, foam panels are used, which applies an additional layer of insulation. You might try painting the walls with a concrete water barrier paint like:

[RT]

:

I don't see any moisture on the walls. So it is still a good idea to paint the walls?

-RT

[RT]

Do i have to get a special sprayer to get the clorox diluted while spraying or just use a bucket and a mug to spread the diluted clorox?

[Mark]

Yes, concrete passes moisture,,, I would paint the walls with two coats of Drylock and consider painting the floor too. You are not supposed to paint floors with Drylock (I don't know why) but I did mine and painting the walls and floor did cut doen on the humidity in the basment.

Also in winter, open at leas one heating register so dry warm air air is pumped into the basment.

Mark

[Stormin Mormon]

The one time I did clorox spray. I used a quart plant mister bottle. Mostly water, about 1/4 Clorox. Some folks say 10%, but I don't always follow directions. In your cellar, I'd be thinking a one or two galon garden sprayer. Start at the far corner, work backwards toward the door, and then get out for an hour or so while the chlorine stink clears. I sprayed mine right before going to the store. When I got back, the shower walls were a heck of a lot cleaner.

[Stormin Mormon]

Might just drill a couple small holes in the return air run -- the furnace can warm the air, and then pump it into the house.