Talk:Cob (material)

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Contents 1 Cost of wall 1.1 External Links 2 Citations? 3 Adobe

[edit] Cost of wall

Re the 4 bedroom cob house in Worcestershire - "The total construction cost was £300 000, but the metre-thick cob outer wall cost only £20 000.." I'm not sure how this compares with ordinary houses - it's expressed as though £20 000 is cheap, but how much would an ordinary wall (or a well-insulated wall) cost in a similar house? --Singkong2005 00:40, 30 May 2006 (UTC)

You're right, it does say it as if it's cheap, which it's not - words like "only" should really be avoided in this context as it represents a POV on what constitutes "cheap" (however if it had cited a comparison it would've been forgivable). This figure of £20,000 is probably incorrect, as it actually costs next to nothing to build a house out of cob (mud and straw is generally free! Also I've got reliable sources stating that cob houses have been built for under £1000 total cost exc. land.) even though to be fair his house was pretty extravagant. The only real cost comes from the use of timber, slate, glass, labour, equipment hire, sand, and the fact that he used shillet in his cob mix. Since the cost of these materials depends mainly on local availability of the material the price is really irrelevant anyway. On the topic of shillet, the article says that Kevin McCabe was the first person to use shillet in cob, which is plain untrue, as I have seen Cornish cob cottages with shillet cob, which was exposed when they were demolished. generally I'd say that the section on McCabe's house is pretty unencyclopedic, and would say delete it until someone can be bothered to cite it - the section doesn't really add anything to the article and what little information it contains is debateable at best. ▫Bad▫harlick♠ 02:07, 28 January 2007 (UTC)

Just noticed the cite for this claim, however I'm still uncomfortable with it as I don't feel that it's representative of the subject, nor is it possible for me to verify without a copy of that newspaper. So my recommendation remains "delete". ▫Bad▫harlick♠ 02:06, 31 January 2007 (UTC)

[edit] External Links

Hello, Was wondering why the external links list keeps disappearing and why some links are being removed. Thanks. - 1/30/07 (Ddraig)

Someone was adding links to sites that were commercial interests, blogs, and/or forums, and an edit war ensued between two contributors, because these types of links aren't allowed unless the circumstances are exceptional (IE the whitehouse website on the whitehouse article, or the coca cola company website on the coca cola article) or if there is a general lack of suitable external websites on the internet. In this case there are lots of good websites on the subject and the circumstances are hardly exceptional. ▫Bad▫harlick♠ 02:00, 31 January 2007 (UTC)

So if I'm understandign this correctly the website promotes a discussion forum, business, or a blog then they are not allowed? What kind of links are acceptable then? I would have thought things like cobprojects.info or cobworkshops.org would be alright? Thanks Again - 1/31/07(Ddraig) —The preceding unsigned comment was added by 12.47.114.250 (talk) 20:46, 31 January 2007 (UTC).

Well, a link is there to expand on the information provided in the article. The idea is to allow the reader to learn more without having to clog up the article with large blocks of text. Therefore, ideally only one or two external links may be necessary, in this case various aspects of cob buildings, both modern and throughout history, as well as techniques and so forth. While I'm sure both the websites you cited there are very informative, does one offer information that the other does not? And is a website requiring the purchase of a product before you can learn more really necessary when we can link to a website that offers the same information for free? These are things that we must consider before adding a link to an external website. ▫Bad▫harlick♠ 03:28, 17 May 2007 (UTC)

I did a quick cleanup of the external links. External links should conform to WP:EL and WP:NOT. In a nutsheel links should go to specific information that could be in the article its self. Linked information needs to conform to WP:NOT re: If the linked page were droped into the article would the article be good enough to be a featured article? I specificaly removed the links to groups/workshops because featured articles do not contain directories of information about people making/thinking about a "thing", they contain information about the "thing" its self. 69.72.93.193 15:01, 5 July 2007 (UTC)

[edit] Citations?

Just put in a request for a citation with regards to cob's claimed benefits. That it's cheap or not has already been discussed here. But has anybody actually done a study stating that cob buildings are resistant to earthquakes? (And no, anecdotes don't cut it--I mean a real study.) It also seems odd to state that cob buildings are "fireproof," and then further down the page (under "Modern Cob Buildings") we have a mention of an Irish cob building that got destroyed by arson. I'd love to see some better references on this page.

Aasmith (talk) 01:55, 18 February 2008 (UTC)

Who would profit from paying for such a study? Cob walls are much thicker than masonry, and this makes them inherently more stable. Tabby (talk) 05:20, 7 March 2008 (UTC)

Expense: If labor is cheap, cob is cheap. I have been involved with the buying of cobbing materials and building cob walls. So I can say from experience that clay(clay rich soil) and sand(sand rich soil) is in very plentiful supply almost anywhere. Buying is cheap and often the materials are given away by excavators. However cobbing is in no way "inexpensive", the materials are nearly free, but the labor is not, so in reality the expense is primarily a cost of labor issue. Even with volunteer labor you still have to realize that cobbing is monitarily inexpensive but labor expensive. For example the "heart house" built by some people from The Cob Cottage Co. was constructed for under $500. It should be pointed out that the walls are easy to build, so its much more possible for ordinary folk to build a house themselves, using their own labor. So really this isn't about references, but rather about more concise language that demonstrates the specific pros and cons.

Fireproof: Cob itself does not burn, so strictly speaking the Cob wall itself IS fireproof. But there's nothing special about the roof, it could burn just like any other. So again this is more about concise language.

Earthquakes: http://seattlepi.nwsource.com/lifestyle/334487_cobseattle06.html "University of British Columbia engineers tested cob's earthquake resistance and, according to one account, the test structure survived a simulated 7.4 quake with only minor cracks, even after prior shaking." Cob houses built in earthquake zones must have some adjustments made to be safe. Wall thickness is clearly a factor but its also advisable to to use a concrete bond beam both at the base of the wall and the top. —Preceding unsigned comment added by 64.112.227.142 (talk) 00:23, 2 May 2008 (UTC)

[edit] Adobe

I don't really get how this is different from Adobe. — Chameleon 23:32, 27 March 2008 (UTC)

To my understanding, it's on two levels: one, the mix is different in creation technique and the content. Two, adobe will degrade in the rain, and is thus only really suitable for dry climates. Cob will not break down in wet weather. VanTucky 23:44, 27 March 2008 (UTC)

Adobe sometimes has straw added, while cob always adds a decent amount of straw. Adobe is preformed into units and dried, before assembling into a structure, while cob is built up on the structure like sculpting. Bodhi.peace (talk) 18:19, 6 April 2008 (UTC)

Cob uses larger proportion of straw than adobe, it also uses longer individual straws. During the process of building a cob wall, straws are laced together by pushing a Cobbers Thumb (a stick) into the wet top layer. The longer strands of straw also creates very small airways which speed in drying, an important factor in the speed of construction. Also, cob is a reference to the building technique of tossing a small lump(cob) from person to person in a line of any length straight up to people on the wall (thus no heavy lifting or hauling equipment). —Preceding unsigned comment added by 64.112.227.142 (talk) 22:49, 1 May 2008 (UTC)