SB: Re: Just what is "adequate" pre compression ??

["Robert W. Tom" <ArchiLogic@yahoo.ca>]

5/29/02 12:10:54 AM, "Pacot, Domingo G" <Domingo.Pacot@team.telstra.com> wrote:

[snip] 
>I would be interested to hear  what measures or rules of thumb people have
>applied to  judge  the strawbale wall as being compressed .

Dom;

In a loadbearing structure, I think that the amount of precompression should, at 
the very least, be equal to or exceed the compression that would be imparted by 
the anticipated vertical loading that the walls will see, in the event that the 
skins for some reason, did not do their intended duty in taking those loads.

Those vertical loads would include any dead loads (ie weight of any floor or 
roofs that are bearing on the walls) PLUS the live loads (ie snow, occupancy 
loads), all multiplied by the appropriate factors of safety for each.

Obviously, a single storey LB building in a climate which never receives any 
snow will not have the same precompression criteria as a two-storey LB building 
in a climate where two to four foot deep snow/ice on the roof is a possibility
(although I would have to wonder why anyone would even consider a LB SB building 
in such a locale).

That being said, if one considers that a precompression load of 2 to 5 pounds 
per square inch in a heavy-duty LB situation (ie two-storey w/snow loading) 
would not be out of the question, if you do the arithmetic, it's easy to see 
that it wouldn't be all that difficult to overstress a one-ton come-along (aka 
"ratchet winch") if one were attempting to precompress a section of two-string 
bale wall as short as 5 lineal feet.


I'm told that in the Olde Days, Californicators like the Skilfull Meany would 
regularly shear off threaded rod or break tools when ratcheting down the top 
plate in an attempt to precompress their three-string bales.

--- * ---
Rob Tom
Kanata, Ontario, Canada
(remove the "chaff" from my edress if you hit "reply")

Please visit http://www.theHungerSite.com daily



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