cabin floor insulation ... is it necessary?

hnash53 · April 27, 2006, 07:32:39 AM

I've been asked to renovate a 16x30 shed into a "mother-in-law" cabin/house. The shed sits on a concrete perimeter foundation with a 3-4' crawl space underneath. The foundation is in good shape and the crawl space is dry and sealed well with very little air movement underneath the structure.

The flooring is 3-4" tongue-&-grooved cedar planks nailed directly to the floor joists and is in good shape. A good sanding is needed. There is no insulation in the floor.

My question: Is insulation needed with a sealed crawlspace underneath? She would like to keep the cedar floor, but understands that insulation might be needed in our Wyoming climate, and therefore the floor must come up.

I think the floor's got to come up. What do y'all think?

Thanks.

Hal

John_M · April 27, 2006, 08:52:56 AM

Can't you put in the insulation from below? This way you won't disturb the existing floor. Icynene would be great if you could afford it!

Daddymem · April 27, 2006, 11:30:02 AM

If you can't get under from the outside, can you remove a small section of the floor and then get under from the inside? You could make the hole under where the bed would go for example, and perhaps make it a permanent door in case you need to get under again. Planning on plumbing? You'll probably want a way to get under anyways.

Amanda_931 · April 27, 2006, 08:35:47 PM

Here in the South we have crawl-spaces that can be entered from the outside.

Up North, I read in a novel once, they do things like trap doors in closets. I thought it sounded weird, but it would make for less air infiltration.

Might want to do that anyway.

But you could also just insulate the foundation, maybe even slant it out underground a few feet.

We won't talk about the logic of the attic in my Nashville house that could only be entered through the vent to the outside (it was bigger than a standard vent--not that much, though).

The heat pump blower was up there.

Guess why it never was repaired or replaced when it died.

keyholefarmhouse · April 28, 2006, 05:24:44 AM

Make sure you have a decent access. Check the controversial ventilation requirments for (western?) WY. Provide area where plumbing might go through floor. Put fibeglass insulation between the joists and maybe pegboard to hold it into place. Sand the floor, seal it with a vapor retardent primer and several coats of polyurethane. Put 6 mil on the ground if ventilation isn't removing what moisture is there.

This is a huge guess on my part and I'm hoping John will grade it.

manhattan42 · April 28, 2006, 07:09:20 AM

Sealed crawslpaces are permitted and are actually more energy efficient that just insulating the floor of the structure alone, but they must be constructed properly.

-Sealed crawlspaces must have their perimeter walls and parts of the floor insulated.
-They must also share conditioned air with the main structure.
-Dirt floors must be sealed with at least 1 layer of 6 mil polyethylene.

Otherwise you have no choice but to insulate the floor and make sure the crawpspace is adequately vetilated.

Here is a helpful link regarding sealed crawlspace design:

http://www.raisedfloorliving.com/crawlspace.shtml

Building codes require access to underfloor spaces either through the floor above or through the foundation wall.

jraabe · April 29, 2006, 01:22:46 PM

Hi Hal:

Is this you?

BTW - good advice guys and gals! Plenty of good info here.

glenn-k · April 29, 2006, 03:27:15 PM

I don't know about keeping them out , Jochen, but maybe thay will at least eventually die of cancer.

Fiberglass Insulation Can Cause Cancer or not depending on which study is true.

This is the first time I have researched this and found a link to cancer, but I did it because I've had 2 dogs die of cancer which I suspected was caused by sleeping on fiberglass insulation in our barn at our other place.

http://consumerlawpage.com/article/fiber.shtml

manhattan42 · April 30, 2006, 06:53:56 AM

Hmm, the information from Glenn's links states quite the opposite: that insulation does NOT cause cancer.

From the American Lung site:

"Yes, fiberglass building insulation is safe when it is properly installed."

""glass fibers do not appear to increase the risk of respiratory system cancer".

"2001- The IARC working group revised their previous classification of glass wool being a possible carcinogen. It is currently considered not classifiable as a human carcinogen. Studies done in the past 15 years since the previous report was released, do not provide enough evidence to link this material to any cancer risk. "

The Consumer Law link contains outdated research from the 70s which has since bene proven invalid.

The latest research concludes insulation to be safe at all exposure levels.

Not even asbestos insulation exposure has created the epidemic of lung cancers that some expected.

glenn-k · April 30, 2006, 09:57:16 AM

Thanks for a view from the industry side, Manhattan. I appreciate your input.

I would say ---- not proven to be invalid.

QuoteFour major manufactures of fiber glass insulation campaigned for three years to prevent their product from being labeled a carcinogen by NTP. They managed to delay the publication of the NTP's Seventh Annual Report on Carcinogens for more than two years, but on June 24, 1994, the Secretary of Health and Human Services (HHS), Donna E. Shalala, signed the Report and sent it to Congress, thus making it official policy of the U.S. government that fiber glass is "reasonably anticipated to be a carcinogen." In the U.S., fiber glass must now be labeled a carcinogen.

I would say ---revised and ignored by big money and the industry and government whores pushing a relatively safe but not totally safe product. As you mentioned, asbestos is not nearly the hazard it once was thought to be, but try to get rid of it. You will pay off lots of government and industry experts as you try to get rid of asbestos through the permit and observation process. You will buy expensive containment materials and pay hazardous disposal fees. Follow the money. Industry has thousands of contractors and certification agencies and government air quility control people and inspectors, based on a material that is not as bad as once thought. Have no doubt--- they will extract the money from the pockets of the public even for a material that is not as bad as once thought if given half a chance. Yes - there is a recreation area in the California coast range where you can ride your dirt bikes through the asbestos mines and associated areas. That still does not mean that a small percentage of the population does not die from it.

In my opinion is typical industry cover up. Read the timeline - yes the official stance after the new tainted studies and payoffs cleaned up the old report is a carefully worded disclaimer. Read the industry purchased doublespeak.

1. "Yes, fiberglass building insulation is safe when it is properly installed.
That says it is not safe when it is not properly installed.

2. "glass fibers do not appear to increase the risk of respiratory system cancer"
That says industry paid for enough other studies by companies that reported in their favor to shed doubt on the original study. It does not say that the original study was proven invalid or even if it did it only indicates that someone was paid off to get the official report out to the public. Caution is still in order considering the state of the money tainted media.

That doesn't really mean it was not a valid report, and I would recommend exercising caution when working with the product. Chances are best that you won't be affected by it other than the bad itch -- or you could be like my two dogs (unscientific study of course) and end up with incureable tumors growing out of your side. Note that other dogs who did not sleep on the fiberglass did not get the tumors. There is way too much money involved for industry to allow a real report with real hazards to stand uncontested if it only affects a small percentage of the population. That does not mean that there is not a small risk to some and a great risk to those susceptable.

The lawyers must still feel that the old report is relevant, as their copyright is current as of 2006.

The toxic soup of formaldehyde and various binders in engineered wood products such as OSB are relatively safe to most people, but try to tell that to a person who is sensitive to it or to a frog floating in a bottle of it in a biology lab. I'll bet they disagree. :-/

One of the tainted revisions you quote above was by the NAS - supported by industry and begging for more industry money in this article - note that to see the tie you have to look at the note at the top and bottom of the page. Copyright © 2006 National Academy of Sciences. All rights reserved. 500 Fifth St. N.W., Washington, D.C. 20001 ----------- Center of the snake pit, industry whores and lobbyists.

Ties Between Academic Research and Industry Should Be Strengthened

http://www4.nationalacademies.org/news.nsf/isbn/0309089735?OpenDocument

"Safe at all exposure levels." Obviously not true. This taken literally advises taking no precautions.

glenn-k · April 30, 2006, 10:49:45 AM

Quote

The fiberglass manufacturing industry includes many of the same corporations which created the asbestos tragedy, except now these corporations are larger and operate in many countries. Despite recent bankruptcies, the fiberglass manufacturers retain much wealth, in the form of factories, brand names and distribution channels. Their long fingers reach into universities and medical centers, where their money pays for " research" on the safety of their products.

This "research" may sound scientific, but always determines the product cannot be proven hazardous. Often, the study logic deceives. For instance, hamsters held captive in a "nose cone" may not always get cancers when exposed to a fiberglass aerosol, but hamsters cannot breathe through their mouth, as people often do, and their furry little noses actually filter fibers very effectively. Their tiny little lungs have nowhere near the capacity, and generate nowhere near the air velocity, of a human exerting themself, say, when installing insulation or running a cable through a hot attic.

Because of its monstrous potential liability, the fiberglass industry can never admit to a sliver of possibility its products cause disease, especially cancer. Any researcher who says otherwise should look for research funding elsewhere.

http://www.sustainableenterprises.com/fin/

Note: I am not a fanatic against fiberglass - I use it - I usually don't use a mask --I am stupid--- I just say that no matter who industry has paid off, there is still a reasonable hazard associated with fiberglass.

This is just more proof that the codes are not totally about safety and are influenced by industry and special interests.

One Family's Story

Thirty Years Installing FiberglassLeaves Texan a Pulmonary Cripple

Hal Nash(Guest) · May 01, 2006, 06:42:05 PM

Thanks for all the info, folks.

The crawl space is very shallow...I couldn't even get below it to put up any insulation anyway.

So the floor will be ripped up and I'll put plastic down on the ground, then installed fiberglass insulation, vapor barrier up, right?

manhattan42 · May 01, 2006, 07:23:09 PM

Glenn said:

"Note: I am not a fanatic against fiberglass - I use it - I usually don't use a mask --I am stupid--- I just say that no matter who industry has paid off, there is still a reasonable hazard associated with fiberglass. "

Well, even paranoids have real enemies, so I am sure that fiberglass if ingested in large enough quantiites, just like too much water, can have a detrimental effect on one's health.

But fiberglass is, after all, just glass.

And glass is just innocuous silica.

You're entitled to all the consiparcy theories and government coverups you can dream up, but I'm a healthy skeptic, and don't believe every bad health claim that comes down the road nor every charge of collusion.

Whole industries have sprung up over such unfounded hysterias...like those of the non-existant toxic mold scares, asbestos related cancer epidemics that have not materialized, unprovable links of cancers to radon and so on.

Such are the stuff of lawyer driven claims that don't even need to be based in scientific or any other kind of reality...One just needs a lawyer to pursuade 12 average people who may barely be able to read, write or even think that his fantasy is supported by the preponderance of the evidence more than the other guy's fantasy...and voila`!

Another way to bilk legitimate business for non-existant damages.

No, I don't represent the 'industry' side of anything.

Just because I happen to be a building and code professional does not mean I'm a shill for anyone.
Especially not the insulation folks.

On the contrary, I take all sides with a healthy dose and have concluded from my own research and readings that claims of cancers from fiberglass are unsubstantiated...and the more research is done the LESS there is any linkage to cancers at all.

I don't need to prove the link doesn't exist.

You and those with your view need to prove there is one.

And to date, like weapons of mass destruction in Iraq, that hasn't materialized...

jonseyhay · May 01, 2006, 09:54:16 PM

Quote"Whole industries have sprung up over such unfounded hysterias...like those of the non-existant toxic mold scares, asbestos related cancer epidemics that have not materialized, unprovable links of cancers to radon and so on".

Somthing like this

http://www.greenleft.org.au/back/2004/598/598p24.htm

Jochen · May 01, 2006, 10:12:09 PM

QuoteI don't know about keeping them out , Jochen, but maybe thay will at least eventually die of cancer.

With all the informations I could collect so far in this thread I can at least let my mice and critters now know that my fibreglass insulated floor will not harm them. Good news for these folks, but nothing that would help me!

Should I cover the insulation also with a thin layer of plywood from below and put some screens in to vent the area? Like I did it for my roof as well? :-/

Jochen

Amanda_931 · May 01, 2006, 10:19:49 PM

Somebody here, a long time ago (pre-YABB?) put little 1 x1's at the bottom of each floor joist, dropped in pieces of pegboard masonite. It was a) a covering for the insulation under the house, b) ventilated and c) easy to remove if somebody needed to get to the under-floor bathroom plumbing or whatever. And there was a picture.

Won't work if the dogs hang out down there, but, with no dogs, it's got a lot to recommend it.

Sassy · May 01, 2006, 11:13:40 PM

How cute! I miss our goat, Cupcake... :'( we figure a mountain lion must have got her... I wouldn't mind having a little donkey, either... (or is that a baby horse?) but have to wait until we're here full time...

I would still take respiratory precautions when dealing with fiberglass, Jochen... even though "fiberglass is, after all, just glass, and glass is just innocuous silica"... sharp, microscopic pieces of glass aren't good for your lungs & also don't feel too good on your skin... :-/ & silica can cause silicosis of the lungs which is not good...

glenn-k · May 02, 2006, 01:04:06 AM

Thanks for keeping this discussion lively, Manhattan.

QuoteBut fiberglass is, after all, just glass. And glass is just innocuous silica.

but silica itself is not innocuous -similar to fiberglass.

I guess I better research the meaning of innocuous - the silica listed in the report below seems pretty dangerous. It will probably be disproven as soon as the sand, gravel and mining industry becomes aware of it.

http://www.nlm.nih.gov/medlineplus/ency/article/000134.htm

and this-

U.S. Department of Labor
October 31, 1996

What Is Silicosis?
Silicosis is a disabling, nonreversible and sometimes fatal lung disease caused by overexposure to respirable crystalline silica. Silica is the second most common mineral in the earth's crust and is a major component of sand, rock, and mineral ores. Overexposure to dust that contains microscopic particles of crystalline silica can cause scar tissue to form in the lungs, which reduces the lungs' ability to extract oxygen from the air we breathe. Typical sand found at the beach does not pose a silicosis threat.
More than 1 million U.S. workers are exposed to crystalline silica. Each year, more than 250 American workers die with silicosis. There is no cure for the disease, but it is 100 percent preventable if employers, workers, and health professionals work together to reduce exposures.
In addition to silicosis, inhalation of crystalline silica particles has been associated with other diseases, such as bronchitis and tuberculosis. Some studies also indicate an association with lung cancer.

Who Is at Risk? glass manufacturing - among others - Is fiberglass manufactured? Innocuous silica associated with the "C" word?

It looks like the CDC is concerned about the lung disease threat from fiberglass. Installing it or being a rodent in it seems like it would be a high risk activity. http://www.cdc.gov/elcosh/docs/d0200/d000257/d000257.pdf

And ---wow ---Manhattan-- you and I even agree on the weapons of mass deception!

glenn-k · May 02, 2006, 01:09:21 AM

Jochen, John had something posted about the proper way to do it somewhere around here- I'll see if I can find it.

Here's some of it

http://www.countryplans.com/cgi-bin/yabb2/YaBB.pl?num=1101910276/1#1

Amanda_931 · May 02, 2006, 06:43:39 PM

Hmm. Fiberglass and cancer. According to the American Lung Association there were some studies back a while that showed enough of a correlation that packages were labled for special care needed to avoid exposure (first link).

More recent studies do not show this, and the warning has been taken off insulation packages.

But.... There has been so much industry funding (posibly especially pharmaceuticals) that the claims may be meaningless.

Plus.... Formaldehyde is not a particularly nice ingredient. Sometimes it is used as a binder in fiberglass insulation (note second link).

I would take anyone who mentions LEED on their site to be a building industry related source. Wouldn't know how that would affect bias here. Sounds, for the moment at least, like "pays your money takes your choice." It will support mold growth if it gets wet and presumably gets some organic matter dust in it. And it's just plain nasty to handle. That last would be my reason for avoiding the stuff.

http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35439

http://builditgreen.org/resource/index.cfm?fuseaction=factsheet_detail&rowid=10

Totally adorable picture Jochen. (the equine looks like a baby!--tail, legs, and the fact that the halter is brand new)