Basement Mustiness ??

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Old 05-27-08, 06:39 AM
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Basement Mustiness ??

Hello. My wife and I recently moved into a new house. The house is 15 years old with a finished basement. The basement is around 1000 sq ft. Attached is a rough drawing of the layout. The basement is about 2/3 the floorplan and the crawspace is about 1/3. All of the walls in the basement are insulated with drywall and a vapor barrier. That is except the unfinished store room in the back. There is a sealed access panel to the crawlspace from the basement. The crawspace is filled with pea gravel and vented to the outside. Unfortunately there are no windows in the basement. The finished areas have a drop tiled cieling so everything is accessable.

The house was uninhabited for a year or so but the previous owners came back everyweekend and took care of it and ran a dehumidifier constantly. With doors closed there is no ventilation between the rooms of the basement. The basement has a musty smell. Not terrible but bad enough I want to do something about it. Its worse on humid days so I am sure it has to do with humidity settling and impropper ventilation.

I have the doors all open (except the one to the upstairs) and two dehumidifiers running 100% of the time. I put a small fan down there to get the air moving a little. Saturday it seemed like it was airing out (we have only been in for 1 week) but then sunday and monday were very humid and yesterday and this am it had a very musty smell to it.

I am not sure what to do about it now. We are just using it for storage right now but the plan is to eventually to put a large TV down there and make it an entertainment area so I want to solve this musty issue. I am sure when we do that eventually we will replace the carpet but putting my nose to the carpet it doesn't really seem like the smell is there. The basement seems dry except for the gauge on one of the dehumidifiers reads 60%+ when it smells musty. The gutters all go 20 feet from the house or so and dump far away.

You can see in the picture there are two small vents into the main room and there is no ventilation between the rooms. There is also no return vent anywhere in the basement.

My thoughts so far are to vent the walls with simple vent grates so the rooms breath together when the doors are closed, but I am not sure that is enough. It seems to me there just isn't enough air circulation down there and I am not sure what to do about it?

Do I put in another return vent down there somewhere? More supply vents?

I wish I could just open some windows and get some fresh air in there.

Any and all suggestions are MUCH appriciated.

 
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Old 05-27-08, 07:17 AM
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Humidity should be maintained between 35-55% year round. A hygrometer, sold where thermometers are sold, can give you the humidity level. Use the proper number or size of dehumidfiers to reduce the humidity.

Close vents to outside, as they allow humid air to enter the basement. Most folks want to open doors and windows to outside to air out a damp basement, but that just lets in the humid air. Fans will help with air circulation.

If you have HVAC in basement, there should be a cold air return. An HVAC pro can advise best placement.

Keeps doors open between basement rooms to allow for air circulation. Keep crawl space access closed. There is likely a poly vapor retarder, as should be, beneath the pea gravel in crawl space.

Do an exterior inspection to make sure that gutters and downspouts are clear and carry water away from structure. Make sure lawn slopes away from foundation to carry away the excess water and there is no standing water around foundation. Sometimes water penetrates foundation walls and gets trapped in finished basement wall voids. Look for signs of moisture along bottoms of walls.

Check cold water pipes to see if condensation is forming on them. If so, cover with pipe insualtion. Condensation can drip and cause mold/mildew and musty odors. Check for leaky pipes.

An enzyme digester deodorizer may also be helpfu.. These are marketed under a variety of names like Out, Nature's Miracle, OdoBan, and others. Deep clean carpets and wash down the walls with enzyme cleaner or disinfectant.
 
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Old 05-27-08, 07:40 AM
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A good dehumidifier like a therma - stor will be able to get the RH down.
 
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Old 05-27-08, 07:56 AM
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Originally Posted by twelvepole View Post
Humidity should be maintained between 35-55% year round. A hygrometer, sold where thermometers are sold, can give you the humidity level. Use the proper number or size of dehumidfiers to reduce the humidity.
I will pick one up

Originally Posted by twelvepole View Post
Close vents to outside, as they allow humid air to enter the basement. Most folks want to open doors and windows to outside to air out a damp basement, but that just lets in the humid air. Fans will help with air circulation.
The only vents to the outside are in the crawlspace and that is sealed off from the basement

Originally Posted by twelvepole View Post
If you have HVAC in basement, there should be a cold air return. An HVAC pro can advise best placement.
That was my immediate thought about the return. Where can I read about vent placement? I hate to call someone out for such a simple job as putting in a vent, I just need to figure out where to put it.

I suppose at this point I might as well cough up the money for an outside company.

Originally Posted by twelvepole View Post
Keeps doors open between basement rooms to allow for air circulation. Keep crawl space access closed. There is likely a poly vapor retarder, as should be, beneath the pea gravel in crawl space.
Crawl space is closed, however I need to keep doors closed off too as the dog has run of the basement durring the day and I don't want her in two of the three rooms which is why I was thinking about adding vents in the walls between the rooms to help with circulation.

Originally Posted by twelvepole View Post
Do an exterior inspection to make sure that gutters and downspouts are clear and carry water away from structure. Make sure lawn slopes away from foundation to carry away the excess water and there is no standing water around foundation. Sometimes water penetrates foundation walls and gets trapped in finished basement wall voids. Look for signs of moisture along bottoms of walls.
I took a look at all that this weekend. Downspouts are all great, grade is great.

Originally Posted by twelvepole View Post
Check cold water pipes to see if condensation is forming on them. If so, cover with pipe insualtion. Condensation can drip and cause mold/mildew and musty odors. Check for leaky pipes.
pipes have also been looked at and they look great and dry.

Originally Posted by twelvepole View Post
An enzyme digester deodorizer may also be helpfu.. These are marketed under a variety of names like Out, Nature's Miracle, OdoBan, and others. Deep clean carpets and wash down the walls with enzyme cleaner or disinfectant.
I have one odor absorber but I will pick up another. I plan to shampoo the carpets well ASAP, though I was worried that would add to the moisture issue?


Originally Posted by airman.1994 View Post
A good dehumidifier like a therma - stor will be able to get the RH down.

I have two and I have been turning one off at night but I will stop doing that.



With all that said it sounds like I need to deep clean the basement and get propper ventilation to rid this problem for good?
 
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Old 05-27-08, 09:25 AM
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Here's a previous discussion re: cold air return placement. There are likely others to be found if you use the Search option. http://forum.doityourself.com/showthread.php?t=330461

Depending on size of dog, baby gates may be an option for doorways. That way you can keep the doors open and the dog in check.

With fans and dehumidifiers running, the temporary increase in humidity from disinfecting carpets and other surfaces should pose no problem. If carpet has cushion beneath, you will not be able to clean and disinfect that.
 
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Old 05-27-08, 09:50 AM
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Originally Posted by twelvepole View Post
Here's a previous discussion re: cold air return placement. There are likely others to be found if you use the Search option. http://forum.doityourself.com/showthread.php?t=330461

Depending on size of dog, baby gates may be an option for doorways. That way you can keep the doors open and the dog in check.

With fans and dehumidifiers running, the temporary increase in humidity from disinfecting carpets and other surfaces should pose no problem. If carpet has cushion beneath, you will not be able to clean and disinfect that.

Well I will start with the simple stuff first then. I'll do some cleaning/disenfecting and get the air moving and see what happens before I go tearing up carpet and replacing things. As of right now I don't *think* the carpet is the source anymore than anything else. It seems more like a humidity problem. We already replaced the electrical panel as it had a lot of signs of moisture from the years and there was buildup on the neutral and ground bars, enough that the screws were siezed. So hopefully this problem hasn't been ignored so long that it caused any other expensive problems...


Oh and I am using a babygate on the doors right now, but its not a long term solution for us. Is there a problem with placing vents in the walls on both sides to encourage air flow?
 
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Old 05-27-08, 01:28 PM
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If you have two therma - stor dehumidifiers running you have a BAD RH problem. That would be somewhere around 200 pints or water per day depending on the temperature in the basement.
 
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Old 05-27-08, 05:24 PM
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Originally Posted by airman.1994 View Post
If you have two therma - stor dehumidifiers running you have a BAD RH problem. That would be somewhere around 200 pints or water per day depending on the temperature in the basement.
No just two regular old dehumidifiers. One whirlpool I have had for 6 years and a new LG that seems to be working better than the old whirlpool. The whirlpool is hooked to a hose and the LG has a 65pint container that fills up daily.

I picked up a RH gauge and with both running and the fan the RH is lower in the basement right now than the main floor so I will keep an eye on it over the next few days. This weekend I will shampoo the carpet and clean the walls and see if we can get the odor to go away and stay away. It for sure needs to be tied into the return on my hvac though.
 
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Old 06-02-08, 05:18 AM
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We had our basement carpet professionally cleaned a few weeks ago and it didn't do any good. Got the stains out, but it still smelled. This weekend I tore out the carpet. We're going to replace it with something, but it won't be carpet. I'm guessing it will some solid surface and then use a rug where needed. That way it can be taken up and removed or aired out if needed.

I picked up an inside/outside digital thermometer/humidity device at radio shack. Everything is closed up and I can get it down to 50% @ 66 degF. Using a portable dehumidifier. I'm wondering if a window AC would work well as a dehumidifier? I'm thinking it will always be cool naturally, so the AC wouldn't kick on, allowing the humidity to rise.

Just my 3 cents...
 
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Old 06-02-08, 06:44 AM
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Off the shelf dehumidifiers do a very poor job of removing moisture in the air at temps below 68 degrees. To remove lots of moisture at cooler temps a better dehumidifier is needed.
 
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Old 06-02-08, 07:02 AM
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Just an update...

I've been trying to leave the doors open but the door to the "kitty hotel" can't be contained with just a baby gate. This is the small room that is long and about 2 foot wide that the previous owner used as storage, its where the litter box and cat food are stored as well, hence why it needs to be closed off. Its seems as though the dog gets bored during they day and tears down the baby gate no matter how tight I put it up...

Anyway, long story short, what I have done so far:

- 2 dehumidifiers
- 1 small fan
- shampooed half the carpets

This weekend it seems to have been better. I have left the fan running 100% of the time and the dehumidifiers as well. I shampooed one room and the smell seems to be getting better. I don't think I am getting used to it, I don't spend enough time down there for that.

I'll keep updating as it goes on.
 
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Old 06-03-08, 06:31 PM
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No change here either, I get about 50% rh at 66 degF. I'm going to look into an installed dehumidifier, currently there is no forced ventilation between the 4 rooms of the basement.

But that lead me to think... Where is the moisture coming from? Currently, there is no condensation and no water leaking anywhere, we don't use the dryer that often. I know the outside humidity (In PA) is around 80%. Is it coming in through the floor? The walls are finished (drywall) but I doubt there's a vapor barrier or even a sealer over the block.

Would sealing/paining the raw concrete floor help?
 
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Old 06-04-08, 04:24 AM
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Moisture is coming from walls and floor! Paint will not stop it.
 
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