I am researching the possibility of buildiong some cob structures on my future property - I have several books on the subject, and have contacted some alternative building sites to get info on the building process - even found out about some workshops. But I'm looking to get some info from people who have either lived in a cob structure, or have at least built one - want a more personal, firsthand perspective of what it is/was like. If there are any cobbers out there, let me know...

-- Julia in Tally (tofubiscuit@excite.com), September 27, 2000

Answers

I am not a cobber but I play one on tv...

Silicosis
A disease of the lungs caused by continued inhalation of the dust of siliceous minerals and characterized by progressive fibrosis and a chronic shortness of breath.

The sand in a persons lungs builds up and scars the interior lung walls until they just dont work. My father has a particularly bad case and I would share the details if you wish.

Unless someone comes up with a sealant to keep the sand from dusting off of the walls I would not use it for a human or long lived animal dwelling but might for other buildings (like a flamables shed).

-- William in WI (thetoebes@webtv.net), September 27, 2000.

Just what materials cause this? Is it just cob, or do rammed earth, concrete, stucco, brick, adobe, and/or other earth-based wall contribute to this disease? What about painting the interior walls, or plastering them? How about a sealer, like for basements? I could really use this info before I settle on firm plans for my own house's materials.

-- Soni (thomkilroy@hotmail.com), September 27, 2000.

The siliceous minerals referred to above are primarily those things made of silicon. Of course, thats things like common sand. Remember all those stories about the health problems associated with asbestos a few years back? Well asbestosis is basically the same thing, glass (modified sand) in the lungs. Its definitely something to be concerned about.

Brick and concrete dont get the "dustiness" associated with the cobb and would be rather safe. You would just get the silicon traces in your lungs that we all pick up. I imagine that rammed earths (and I know very little about it) relative safeness is determined by how much sand is in the earth that is being used and what ratio the earth to concrete is...most rammed earth Ive seen have had a finished interior which would sheath possible silicon contaminants away from you anyway. Most cobbs (to my understanding) have exposed interior walls but I suppose that a person could come up with a way to isolate themselves from the walls but wouldnt that defeat some of the purposes of building with cobb?

I honestly dont know if there is a good sealant. Whatever you use would have to be strong enough to lend some kind of surface strength to the wall so that it cant "dust", maybe something with a consistancy like a heavy paint or some kind of sealant that would actually glue the surface particles together as it sunk in. If you used something that seals but doesnt lend structure (thin liquid wood sealants come to mind) then you would just wind up with sealed dust particles.

Remember though that while I do know quite a bit about silicosis, I dont know anything about cobb sealants so take those thoughts for what their worth.

-- William in WI (thetoebes@webtv.net), September 28, 2000.

Thank you for your information. It will go into the mix.

-- Soni (thomkilroy@hotmail.com), September 28, 2000.

Thanks for the info. For those interested in further information, I emailed some of the cobsites on the net, and am getting some good answers (tried to paperclip them to this but couldn't). Just typed in the search word of cob building and several good sites came up. While they are cob builders (so may be biased), they did answer the questions I had in what seemed a forthright manner. Will still consider cob, but as with any building, need to research and use reccommended building methods. They brought up a good point to me about that - the traditional building materials we use are so treated with chemicals, they cause people problems all the time, it just usually isn't recognized as being related to the building materials because it can take so long for symptoms to build up in the body. Seems as if we aren't safe anywhere!

-- Julia in Tally (tofubiscuit@excite.com), September 29, 2000.

Julia, formaldehyde is biggest problem with building materials especially particle board and carpet. The sickness caused from this stuff is called new building syndrome. Dee's sight in the archives - need advice about a serious problem-(that may not be exact wording) has lots of info on the subject. It's a growing problem.

-- Cindy (atilrthehony_1@yahoo.com), October 01, 2000.

Asbestos is absolutely NOT the same as silica. Silica is SiO2 (Silicon Dioxide). Asbestos can be one or more of several different minerals, the most common being a form of Serpentinite, which is MgSiO2, (Magnesium Silicate). Neither of them is a form of glass. Technically, glass is not even a mineral, but is considered a "supercooled liquid"; it is non crystaline.

Some forms of Asbestos are worse than others. The most deadly form is "amphibole" asbestos, which can cause mesothelioma, a cancer of the lining of the abdomen, which is always (supposedly) fatal. It takes many years of exposure to this before cancer rears its ugly head. This is why asbestos is considered way more dangerous for kids than adults, as the kids will potentially be exposed for a longer time span.

Silicosis, caused by inhalation of silica and other particulate matter, is primarily a disease of miners, glass makers, sand blasters, and other high risk jobs. You have to breathe an awful lot of silica dust to get silicosis. It generally takes about ten years of serious exposure to cause silicosis.

If silica were as hazardous as William of Wi says, everyone who ever lived in Lubbock, Texas would have silicosis. We used to breathe what passed for air, filled with silica, for several weeks every spring and every autumn.

Asbestosis IS similar to silicosis, but again, it is a disease of those who breathe a lot of asbestos dust, such as miners, carvers of asbestos related minerals such as soapstone, talc, and serpentine rock; it, too, is an occupational hazard, rather than a hazard to an average homeowner. The big risk of asbestos exposure to the average worker is cancer, which can be caused by much, much smaller doses, such as having a roadway next to your house which is surfaced in Serpentine rock containing asbestos fibers.

Don't worry about getting silicosis from a cobb house. Dumb.

William from Wi., you still haven't answered my question from two months ago, as you promised....

JOJ

-- jumpoffjoe (jumpoffjoe@yahoo.com), October 03, 2000.