Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
Traditionally crawl spaces were vented, but they don't freeze as the ground stays relatively warm here. Some newer construction or retrofits will use a closed crawl space design. A bit of mechanical dehumidification is usually provided. A closed crawl can actually be a fairly nice space ... and makes good sense in my opinion.
It's usually a good sign to see bugs in a vented crawl. A lack of bugs can indicate that a snake is being well fed :-)
Frank
The first house I bought in North Carolina had a black snake living in the walk-in crawl space. Apparently the previous owner used to leave the door to the crawl space open all the time. Our home inspector found it and promptly removed it so I didnt have to explain it's presence to my wife. We were "blessed" with many other snake sightings over the 5 years we lived there. That house also had a snake skin in the attic as well, but think that was many years old.
The same house had a river running through the crawl space which caused some mildew growth on the ductwork in the crawl (didnt find that out until the buyer's inspection when we went to sell). Cause was a clogged gutter drain extension, gutter filled up with water and overflowed during heavy rain, overflow ran under the house, causing the "river" which helped form the mildew. Relatively easy fix.
Our last two houses had full daylight basements. At first it was fun but then got to be a pain. It's too easy to save stuff like original boxes for every purchase my husband has made in 40 years of marriage. (this was because you can sell stuff for more if it has the original box but of course he never gets around to selling anything.
it's too easy to purchase stuff you don't really need cause it's such a good bargain and "we can always put it in the basement" and it is too easy for relatives to ask "can we keep this in your basement for a few months until we get our house sold, the divorce is final, we find a new house.....etc".
The new house we bought in Chapel Hill has a nice crawl space where you can actually stand up in some sections. Still DH stores partially filled paint cans, screens we took off the windows and other "treasures". Once a pack rat always a pack rat.
While it is true that you don't know if you have radon unless you test for it, the number of tests performed in this area (10's of thousands) over the last several years have resulted in accurate information as to where you are most likely to find it. There are areas where it should always be tested and others where the statistical chance of having it is so low that (in my opinion) it is a waste of money. Some people choose to do it just for peace of mind. You can indeed have radon in one house and not an adjacent one-I've seen it on multiple occasions.
As far as "safe" levels, the EPA action level is 4.0 picocuries. If you read the chart, the fine print spells out this is a constant exposure is over a lifetime-people are just not typically exposed in this manner. Assessment of Risks from Radon in Homes | Radon | US Environmental Protection Agency
What you don't seem to be taking into account (and why I brought it up in this thread) is that sealing a crawlspace in many cases has been shown to propel the levels of radon by a factor of 2-5. So that 4.0pcl can quickly become between 8.0 and 20.0 once the vents are closed up and the gas has nowhere else to travel except inside the home. Sealing crawlspaces is something that has grown in popularity recently, so it's a relatively new issue and too early to tell how many people will be harmed from failing to measure their radon levels after making changes to their foundation ventilation scenarios.
As you pointed out, the EPA action level is 4.0pcl but this is NOT considered "safe". Radioactive gas is what it is and long-term exposure to radiation has health consequences.
I don't know how anyone can consider testing for it a waste of money. The low-end test canisters are a few bucks at Lowes. You can buy a continuous monitoring device for a reasonable cost online. How much does it cost for even one family member to get lung cancer, die of pulmonary edema, or just spend fortunes in doctor bills for chronic bronchitis? Radon has even been linked to skin cancer.
People will spend thousands on medical care chasing down unknown illnesses, but won't spend a few dollars to test their home to see if it's a cancer factory or not. The average intelligence level of the typical consumer is absolutely astonishing.
Here are some folks who wish they had paid a bit more attention to the dangers of radon:
pdocstr,
Sealed crawlspaces can absolutely increase radon levels as they acts like a basement. I have personally seen this on many occassions. However, in regards to the link, there is no way to determine that radon was the specific cause of their lung cancer. There are many factors that can cause lung cancer, not just radon. Exposure to 2nd hand smoke, a large number of chemicals, heredity, being a previous smoker, etc.
Please note the bottom of the EPA chart as it has some important information. At 4.0 picocuries, a non-smoker has a .7% chance of lung cancer if exposed to this level continuously over a lifetime. People just aren't exposed in this manner which in my opinion renders this chart somewhat useless. The radon level in free air is typically around.4-.5. There are many things far much more dangerous than radon!
If you are living in an area with known radon issues, by all means test for it, if you've made changes to the house (such as sealing the crawlspace) then by all means test for it. If you live in Clayton off of exit 312----don't waste your money as statistically the chances of having a high level of radon are probably well below 1%.
Crawl space means the house is lifted off the ground, raised up by piers. Advantage to me is excellent air circulation. Keeps the structure high and dry. NC wood houses would be easily attacked by termites if the wood was wet, but this way none of the wood is near the ground and the wood does not get wet by wicking up water. Although the house is on piers, there are brick 'curtain walls' between the outer piers, which gives a neat, solid appearance. There are also air vents, and side doors to allow entry for fixing pipe and ductwork, and for yearly insect inspections.
Plus, if there was any radon in the area, it would never get in your house. It would just dissipate innocently like it does from the rest of the ground surrounding your home.
I have a one story, 1920's home--no termites in a termite prone area.
Our last two houses had full daylight basements. At first it was fun but then got to be a pain. It's too easy to save stuff like original boxes for every purchase my husband has made in 40 years of marriage. (this was because you can sell stuff for more if it has the original box but of course he never gets around to selling anything.
it's too easy to purchase stuff you don't really need cause it's such a good bargain and "we can always put it in the basement" and it is too easy for relatives to ask "can we keep this in your basement for a few months until we get our house sold, the divorce is final, we find a new house.....etc".
The new house we bought in Chapel Hill has a nice crawl space where you can actually stand up in some sections. Still DH stores partially filled paint cans, screens we took off the windows and other "treasures". Once a pack rat always a pack rat.
You have just described my hubby and our 3rd floor walk-up attic!
Yep, you got it! mine has a dirt floor and lots of cobwebs. I refuse to go down there and that is where the pipes and hot water heater are-which doesnt make since given we do have winter here. I'd kill for my old basement. I have nowhere to store anything.
So now we need a basement to store stuff we don't need
pdocstr,
Sealed crawlspaces can absolutely increase radon levels as they acts like a basement. I have personally seen this on many occassions. However, in regards to the link, there is no way to determine that radon was the specific cause of their lung cancer. There are many factors that can cause lung cancer, not just radon. Exposure to 2nd hand smoke, a large number of chemicals, heredity, being a previous smoker, etc.
Please note the bottom of the EPA chart as it has some important information. At 4.0 picocuries, a non-smoker has a .7% chance of lung cancer if exposed to this level continuously over a lifetime.
But per the chart, .7% is about the same as your risk of dying in a car crash. Does that number incline you to recommend against the wearing of seat belts? Do you not know someone who has died in a car crash? And even if they don't die, getting maimed in a car crash is probably not fun either. The chart does not represent ALL dangers of radon, only the most severe.
That chart represents non-smokers and does not even begin to address situations where folks may have been exposed to second hand smoke in their lifetime, which also elevates their risk.
What's more, lung cancer IS NOT THE ONLY THREAT. A known carcinogen is a known carcinogen, period. That chart only covers lung cancer. It does not begin to describe risks involved with ongoing pulmonary problems, some of which are often misdiagnosed as allergy issues. Not all problems lead to full blown tumors in the short-term, but can impact quality of life quite a bit.
Quote:
Originally Posted by carcrazy67
People just aren't exposed in this manner which in my opinion renders this chart somewhat useless.
If it's somewhat useless, why did you just cite it as evidence to support your claim?
Quote:
Originally Posted by carcrazy67
The radon level in free air is typically around.4-.5. There are many things far much more dangerous than radon!
It goes without saying there are other things more dangerous, but there are few things that are as dangerous and simultaneously out of sight/out of mind. It is the fact you cannot see it, or smell it, combined with the fact that the human mind tends to be too narrow to realize the threat of such things that make it such a dangerous toxin.
If we decide to take up base jumping off bridges as hobby, we know of the dangers because we can envision ourselves going "kersplat" if the parachute doesn't open. Any human mind has no problems registering that as a danger. However, an omnipresent radioactive gas that has no color or order and no way to detect it without a proactive awareness on the part of the homeowner is a serious enough public health issue that it makes sense to try to reach out and create awareness of it, much like we do breast cancer.
Much of the position you've taken on the subject thus far sounds a lot like the position tobacco companies used to take about the "unproven dangers" of smoking.
Quote:
Originally Posted by carcrazy67
If you are living in an area with known radon issues, by all means test for it, if you've made changes to the house (such as sealing the crawlspace) then by all means test for it. If you live in Clayton off of exit 312----don't waste your money as statistically the chances of having a high level of radon are probably well below 1%.
Only fools fail to test for it, at least occasionally, especially if they have a sealed crawlspace. Only fools.
I guess its up to the consumer whether to believe the EPA or random opinions from a forum like this.
What you don't seem to be taking into account (and why I brought it up in this thread) is that sealing a crawlspace in many cases has been shown to propel the levels of radon by a factor of 2-5. So that 4.0pcl can quickly become between 8.0 and 20.0 once the vents are closed up and the gas has nowhere else to travel except inside the home. Sealing crawlspaces is something that has grown in popularity recently, so it's a relatively new issue and too early to tell how many people will be harmed from failing to measure their radon levels after making changes to their foundation ventilation scenarios.
As you pointed out, the EPA action level is 4.0pcl but this is NOT considered "safe". Radioactive gas is what it is and long-term exposure to radiation has health consequences.
I don't know how anyone can consider testing for it a waste of money. The low-end test canisters are a few bucks at Lowes. You can buy a continuous monitoring device for a reasonable cost online. How much does it cost for even one family member to get lung cancer, die of pulmonary edema, or just spend fortunes in doctor bills for chronic bronchitis? Radon has even been linked to skin cancer.
People will spend thousands on medical care chasing down unknown illnesses, but won't spend a few dollars to test their home to see if it's a cancer factory or not. The average intelligence level of the typical consumer is absolutely astonishing.
Here are some folks who wish they had paid a bit more attention to the dangers of radon:
I'm all for testing for radon ... it's easy and cheap (two kits for $10 at the link here - Purchase a kit).
That said, our home in NW Raleigh was built in '92 as a vented crawl. We closed the crawl about three years ago (I don't use the word "sealed" because its not accurate). We've done numerous radon tests over that time - averaging 1.5 pcl with no readings over 1.7 pcl. Same results vented crawl or closed crawl. Same results with HVAC on or off (our closed crawl runs slight positive air pressure when we operate the HVAC as we use an HVAC duct, but no return, in our crawl for dehumidification).
My takeaway is that the site characteristics are much more important that the construction type. If we had high levels of radon in a vented crawl, I wouldn't count on the open vents to provide remediation.
I'm all for testing for radon ... it's easy and cheap (two kits for $10 at the link here - Purchase a kit).
That said, our home in NW Raleigh was built in '92 as a vented crawl. We closed the crawl about three years ago (I don't use the word "sealed" because its not accurate). We've done numerous radon tests over that time - averaging 1.5 pcl with no readings over 1.7 pcl. Same results vented crawl or closed crawl. Same results with HVAC on or off (our closed crawl runs slight positive air pressure when we operate the HVAC as we use an HVAC duct, but no return, in our crawl for dehumidification).
My takeaway is that the site characteristics are much more important that the construction type. If we had high levels of radon in a vented crawl, I wouldn't count on the open vents to provide remediation.
Frank
Yes, all I'm saying is to test for it. Testing is cheap, and even if a home does need radon treatment its a relatively inexpensive procedure. The only truly foolish move is to be completely oblivious to the danger and never test for it due to false complacency that a given area is impervious to it.
Radon is tricky and unpredictable, and can defy both characteristics of the site and the construction. You could have the lowest possible radon reading most of the time, while your next door neighbor could be averaging 8 or 10 pcl. Opportunities for radon entering the home come and go with time, seismic activity, weather patterns, etc.
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
