Go Back   DIY Chatroom Home Improvement Forum > DIY Repair > General DIY Discussions

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-23-2010, 08:03 PM   #1
Member
 
Join Date: Jan 2010
Location: AL
Posts: 156
Rewards Points: 152
Unhappy

Bad smell in crawl space.


Need help with a really bad smell in my crawl space.

About a month ago, when the summer heat and humidity first hit us (north Alabama), a corner of our crawl space started to stink of cat urine. I got a good UV flashlight and looked/sniffed every where – over the entire crawl space. I couldn’t find anything – no urine, no poop, no dead animals, and no mold – anywhere down there.

Next, I misted some odor remover (bacteria and enzyme type) on the tarp in that corner. That stopped the urine smell overnight – and it stayed gone.

Unfortunately, a different smell was ready for us the next day. It’s not a mold smell, a urine smell, a poop smell or a dead animal smell. It’s not a chemical smell. I guess it’s a cross between the usual earth smell in the crawl space and something like a weak dead animal smell. But it’s very strong.

I sprayed the tarp again with the odor remover and it just made the smell a little worse. The smell seems to be triggered by moisture since on dry days, it is not as bad. I pulled the tarp out of the crawl space. It stinks a lot, especially when it’s damp. The smell under the house is still strong though, even with the tarp gone.

I pulled one of the batts of insulation out from between the floor joists. When dry, it has a slight odor. After I misted it with the odor remover it started to stink just like the tarp. On the other hand, the empty space between the joists, where that batt used to be, smells good now – just a nice wood smell.

The smell is only present in the south west corner of the crawl, pretty much limited to the area originally covered by the tarp. I put the gray tarp over our radon barrier, in that corner of the crawl, to protect the barrier from damage. That’s a high traffic area – between the door and the HVAC system.

The entire crawl space “floor” is covered by the radon “barrier”. It’s about two years old. The barrier material is white on one side and black on the other, with built-in rip retarding thread. It is bonded to the walls with polyurethane adhesive. All junctions are overlapped by 12” and taped together.

I’ve been blowing the smell out one of the vents with a box fan.

My next step will probably be to pull out all the insulation in that corner of the crawl.

Are there any other options? Is there a better odor removal product – maybe with a fogger that would get into every little crack?

Any ideas about what might have caused this smell?

Thanks.
Attached Thumbnails
Bad smell in crawl space.-1-north-ne.jpg   Bad smell in crawl space.-2-north-nw.jpg   Bad smell in crawl space.-3-south-sw.jpg   Bad smell in crawl space.-4-south.jpg   Bad smell in crawl space.-5-south-se.jpg  

Bad smell in crawl space.-tarp.jpg  

John_W is offline   Reply With Quote
The Following User Says Thank You to John_W For This Useful Post:
luvdairish (07-25-2010)
Old 07-23-2010, 08:08 PM   #2
Member
 
Join Date: Jan 2010
Location: AL
Posts: 156
Rewards Points: 152
Default

Bad smell in crawl space.


Here are some more pictures.
Attached Thumbnails
Bad smell in crawl space.-space-between-joists-insulation-removed.jpg   Bad smell in crawl space.-insulation-foil-side.jpg   Bad smell in crawl space.-insulation.jpg   Bad smell in crawl space.-tarp-close-up.jpg   Bad smell in crawl space.-sw-corner-pier.jpg  


John_W is offline   Reply With Quote
Old 07-24-2010, 08:04 AM   #3
Household Handyman
 
Join Date: Feb 2009
Location: Albany, Ga.
Posts: 2,280
Rewards Points: 1,012
Default

Bad smell in crawl space.


John, this may help you: The photos posted are similar to the underside of my home, but without the HVAC unit and water heater. I have only a high crawl space with a vapor barrier on the dirt floor. BUT: You are in N. Alabama and if I remember correctly you also have red clay soil such as we have here in S.W. GA. I had a similar odor problem just a couple of years after I bought this home, which had sat for sale for two years. We had an addition being done where I work and had a Geologist on site, so I asked if I could hire him to look at my lot. Thankfully he did it for a free home-cooked meal. Looking at my lot, from the street, it slopes from right front corner back to the left rear corner, with an elevation drop of maybe 18"--20". The Geologist told me that water would run through this red clay soil more-so than most other soils. Therefore, water was running through this soil, going through the concrete blocks of my foundation wall, and into the red clay soil under the home, being trapped under the vapor barrier (which was doing it's job) and causing a "musty/moldy" smell. He went under the home, dug a hole maybe 12" deep X 12" in diameter and it filled with water in less than five minutes--not good. He recommended an "Open French Drain" system at the inside perimeter of the foundation, which all led to a brick pit with a sump pump for discharge to the outside. This works--a lot, even in dry weather. The placement of a fan at one of the foundation vents was a big help also. I mounted a squirrel-cage type unit from a split A/C system to the foundation wall, on a timer for twice a day, and this has worked very well. No more musty/moldy odors in the house. David
Thurman is offline   Reply With Quote
Old 07-24-2010, 10:54 AM   #4
Member
 
Join Date: Jan 2010
Location: AL
Posts: 156
Rewards Points: 152
Default

Bad smell in crawl space.


Quote:
Originally Posted by Thurman View Post
John, this may help you: The photos posted are similar to the underside of my home, but without the HVAC unit and water heater. I have only a high crawl space with a vapor barrier on the dirt floor. BUT: You are in N. Alabama and if I remember correctly you also have red clay soil such as we have here in S.W. GA. I had a similar odor problem just a couple of years after I bought this home, which had sat for sale for two years. We had an addition being done where I work and had a Geologist on site, so I asked if I could hire him to look at my lot. Thankfully he did it for a free home-cooked meal. Looking at my lot, from the street, it slopes from right front corner back to the left rear corner, with an elevation drop of maybe 18"--20". The Geologist told me that water would run through this red clay soil more-so than most other soils. Therefore, water was running through this soil, going through the concrete blocks of my foundation wall, and into the red clay soil under the home, being trapped under the vapor barrier (which was doing it's job) and causing a "musty/moldy" smell. He went under the home, dug a hole maybe 12" deep X 12" in diameter and it filled with water in less than five minutes--not good. He recommended an "Open French Drain" system at the inside perimeter of the foundation, which all led to a brick pit with a sump pump for discharge to the outside. This works--a lot, even in dry weather. The placement of a fan at one of the foundation vents was a big help also. I mounted a squirrel-cage type unit from a split A/C system to the foundation wall, on a timer for twice a day, and this has worked very well. No more musty/moldy odors in the house. David
David,

Thanks for your comments.

It sounds like you get even more water in the crawl than we used to.

We also have red clay, on a sloping yard (we live on the lower slopes of a mountain) - with a drop of about 3 feet under the house itself - north to south. And we once had water running into the crawl space from under the foundation (in the high NW corner in the picture).

About 15 years ago, we had a general contractor put in a deep french drain parallel to the high (north) side of the house, about 5 feet from the house, and slope the surface dirt strongly to channel rainfall to that same distance from the house. That work, plus a berm installed by the city, uphill from our property, really dried out the crawlspace. When I crawl around down there, I never find any soft spots.

So, I'm pretty sure our current moisture source is mostly the water vapor coming in through the crawl space vents. It's bad enough to cause condensation on the main HVAC supply duct, and sometimes even on the insulation between the floor joists.

In fact, this year, after the first wave of humidity hit us, I found little pools of water on the radon barrier, near the north side vents, but uphill from the HVAC supply duct. It had rained inside the crawl space!

After this odor problem is resolved, I'm thinking of sealing all the vents/gaps in the crawl space walls and using a 70 pint/day dehumidifier down there.
John_W is offline   Reply With Quote
Old 07-25-2010, 07:35 AM   #5
Member
 
Join Date: Jul 2008
Location: Canada (s/w ON.)
Posts: 2,294
Rewards Points: 1,000
Default

Bad smell in crawl space.


At my place I had an odour problem in the crawl space that I couldn't figure out.

It turned out that the Transite (concrete) pipe leading to the septic tank had cracked inside the foundation wall.
There is no flex with Transite and settlement of the septic tank broke the pipe at its fulcrum point.
Replacement with ABS ended the problem.

Here in the north, we now seal the crawl space from outside air and make it part of the conditioned air space. Since I sealed mine, its been perfectly dry.

When hot, moist air enters a cooler area, it releases its moisture as it cools. This moisture pools and eventually causes mold growth.
Wildie is offline   Reply With Quote
Old 07-25-2010, 11:10 AM   #6
Member
 
Join Date: Jan 2010
Location: AL
Posts: 156
Rewards Points: 152
Thumbs up

Bad smell in crawl space.


Quote:
Originally Posted by Wildie View Post
At my place I had an odour problem in the crawl space that I couldn't figure out.

It turned out that the Transite (concrete) pipe leading to the septic tank had cracked inside the foundation wall.
There is no flex with Transite and settlement of the septic tank broke the pipe at its fulcrum point.
Replacement with ABS ended the problem.

Here in the north, we now seal the crawl space from outside air and make it part of the conditioned air space. Since I sealed mine, its been perfectly dry.

When hot, moist air enters a cooler area, it releases its moisture as it cools. This moisture pools and eventually causes mold growth.
Thanks Wildie,

Glad you found the problem.

Do the building codes up there allow sealed crawl spaces? It makes even more sense, down here, but I would be surprised if our codes allow it.

My initial plan is to use a dehumidifier, along with sealing the vents. I don't know if I need to put any conditioned air in the crawl. I have to be careful not to mess up the operation of the radon mitigation system. My radon contractor said that sealed vents plus a dehumidifier would not affect it's performance.

Baby steps.

I'm going under the house now to remove a bunch of smelly fiberglass insulation.
John_W is offline   Reply With Quote
Old 07-25-2010, 11:34 AM   #7
Member
 
Join Date: May 2010
Location: New Jersey
Posts: 114
Rewards Points: 87
Default

Bad smell in crawl space.


Your crawl looks a lot like mine. However, I don't have all the nice moisture control items (fan, vapor barrier, etc.). Given me some good ideas on how to setup mine! Thanks for sharing!! Best of luck
luvdairish is offline   Reply With Quote
Old 07-25-2010, 03:31 PM   #8
Member
 
Join Date: Jul 2008
Location: Canada (s/w ON.)
Posts: 2,294
Rewards Points: 1,000
Default

Bad smell in crawl space.


Quote:
Originally Posted by John_W View Post
Thanks Wildie,

Glad you found the problem.

Do the building codes up there allow sealed crawl spaces? It makes even more sense, down here, but I would be surprised if our codes allow it.

My initial plan is to use a dehumidifier, along with sealing the vents. I don't know if I need to put any conditioned air in the crawl. I have to be careful not to mess up the operation of the radon mitigation system. My radon contractor said that sealed vents plus a dehumidifier would not affect it's performance.

Baby steps.

I'm going under the house now to remove a bunch of smelly fiberglass insulation.
If our codes don't require a closed crawl space, its certainly recommended by the building department.

I'm not familiar with the use of a radon shield. I would think that there would have to be a method of venting these gases. Do they vent to a roof stack?
Wildie is offline   Reply With Quote
Old 07-25-2010, 06:33 PM   #9
Member
 
Join Date: Jul 2008
Location: Canada (s/w ON.)
Posts: 2,294
Rewards Points: 1,000
Default

Bad smell in crawl space.


Here's a link to an interesting article about crawl space venting!

http://www.askthebuilder.com/543-Cra...ce-Vents.shtml
Wildie is offline   Reply With Quote
Old 07-25-2010, 07:51 PM   #10
Registered User
 
Join Date: Mar 2009
Posts: 9,968
Rewards Points: 2,000
Default

Bad smell in crawl space.


http://www.advancedenergy.org/buildi...l%20Spaces.pdf

Check with local B.D. before changing from vented to closed: http://www2.iccsafe.org/cs/committee...E_06_64_07.pdf

Be safe, Gary
__________________
If any ads are present in my answer above, I do not condone/support/use the product or services listed, they are there against my permission.
Gary in WA is offline   Reply With Quote
Old 07-25-2010, 08:25 PM   #11
Member
 
Join Date: Jan 2010
Location: AL
Posts: 156
Rewards Points: 152
Default

Bad smell in crawl space.


Quote:
Originally Posted by Wildie View Post
If our codes don't require a closed crawl space, its certainly recommended by the building department.

I'm not familiar with the use of a radon shield. I would think that there would have to be a method of venting these gases. Do they vent to a roof stack?
The pictures show the exhaust stack - inside and outside. The fan is in the box at the bottom of the stack on the outside. Inside the crawl, the PVC from the bottom of the fan attaches to a pipe, under the radon barrier, that runs the length of the crawl. That pipe has holes all along it that pull air from under the radon barrier.

This area has radon coming off uranium in the bedrock. Our house is built on the bedrock, or within a foot of it on all sides. People a few miles away, in the valley or flat lands, who have many feet of red clay under their homes don't have a radon problem.
Attached Thumbnails
Bad smell in crawl space.-100_1090.jpg   Bad smell in crawl space.-100_1127.jpg  
John_W is offline   Reply With Quote
Old 07-25-2010, 08:28 PM   #12
Member
 
Join Date: Jan 2010
Location: AL
Posts: 156
Rewards Points: 152
Default

Bad smell in crawl space.


The inside picture was taken before the barrier was placed over the pipe and glued to the walls with polyurethane.
John_W is offline   Reply With Quote
Old 07-25-2010, 08:35 PM   #13
Member
 
Join Date: Jan 2010
Location: AL
Posts: 156
Rewards Points: 152
Default

Bad smell in crawl space.


Quote:
Originally Posted by GBR in WA View Post
http://www.advancedenergy.org/buildi...l%20Spaces.pdf

Check with local B.D. before changing from vented to closed: http://www2.iccsafe.org/cs/committee...E_06_64_07.pdf

Be safe, Gary
Thanks Gary.

I don't have foam plastic insulation in the crawl. Are the sections of code in your second .pdf just for foam insulated crawl spaces?
John_W is offline   Reply With Quote
Old 07-25-2010, 08:41 PM   #14
Member
 
Join Date: Jan 2010
Location: AL
Posts: 156
Rewards Points: 152
Default

Bad smell in crawl space.


Quote:
Originally Posted by Wildie View Post
Here's a link to an interesting article about crawl space venting!

http://www.askthebuilder.com/543-Cra...ce-Vents.shtml
Thanks again.

I guess I will check with the local building department before I close the vents.
John_W is offline   Reply With Quote
Old 07-25-2010, 09:29 PM   #15
Member
 
Join Date: Jul 2008
Location: Canada (s/w ON.)
Posts: 2,294
Rewards Points: 1,000
Default

Bad smell in crawl space.


Quote:
Originally Posted by John_W View Post
The inside picture was taken before the barrier was placed over the pipe and glued to the walls with polyurethane.
Thanks for taking the trouble to explain John. Where I live, radon is unheard of, although there are area's within a days drive, where it is a problem.

Wildie is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Smell coming from all floor registers. John_W HVAC 9 06-27-2010 09:57 AM
Water in crawl space after it rains and other questions about crawl space. dupaloop General DIY Discussions 1 04-13-2010 05:58 AM
Crawl Space Insulation skinny2 Building & Construction 10 12-12-2008 11:36 AM
crawl space and moisture Jeremy Hillary Boob, PhD Building & Construction 5 11-27-2008 08:13 PM
Crawl Space In Basement -- Please Help thekid Building & Construction 7 01-04-2008 08:15 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.