[Strawbale] Re: round houses

[André de Bouter]

Hello Rikki,

Rob Tom said ....If bending/laminating 19mm thick lumber into curves is 
deemed to be too challenging, then making the beam an octagon (or 
similar polygon) would do the trick but wouldn't be a continuous (and 
hence stronger) beam as in the case of the former....

One way of making the fabrication of the curved ring beam easier is to 
make it on the foundation before the bales go up. That way you have the 
exact curve and something solid to work with to keep your planks in 
place before all is glued/hamered/bolted in place. You then place the 
ringbeam aside (in pieces if it is a very big and heavy beam) so the 
wall can be raised).

Bye,

André


Rob Tom a écrit :
> On Tue, 20 Mar 2007 06:13:16 -0400, Rikki  Nitzkin 
> <rikkinitzkin at earthlink...> wrote:
>
>> Can anyone send me photos/advice about building round roof/base 
>> plates for loadbearing, round SB houses?
>
> Rikki and You're-o-pee'in RoundHeads;
>
> Assuming that you wouldn't try to make a wall-width, monolithic 
> cast-in-place concrete beam that would be nothing more than a massive 
> thermal bridge (but would be the easiest to fabricate),  box beams 
> using laminations of 19mm thick (or similar) lumber (staggering the 
> joints from one lamination to the next, as well as offsetting the  
> joints in the web material and adding shear plates at those joints) to 
> construct the cords would be a good choice-- "good" in the sense that 
> box beams would consume a minimum of lumber while providing the 
> necessary strength and insulative properties consistent with the SB 
> walls on which they sit.
>
> The sizing of the chords and webs would need to be determined for the 
> specific loading conditions.
>
> If bending/laminating 19mm thick lumber into curves is deemed to be 
> too challenging, then making the beam an octagon (or similar polygon) 
> would do the trick but wouldn't be a continuous (and hence stronger) 
> beam as in the case of the former.
>
> The joints would be re-inforced most easily with the use of steel 
> bands at the outer face to provide the tension to resist outward 
> thrust (assuming no centre pole or collar ties) and sheet steel or 
> sheet lumber gussets across both faces of the joints to resist shear.
>
>
> === * ===
> Rob Tom
> Kanata, Ontario, Canada
> <A r c h i L o g i c   at  c h a f f y a h o o   dot   c a >
> winnow the chaff from my edress in your reply
> --=== * ===
> Rob Tom
> Kanata, Ontario, Canada
> <A r c h i L o g i c   at  c h a f f y a h o o   dot   c a >
> winnow the chaff from my edress in your reply
>
>
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