[GSBN] R value export straw blocks?

[Peter Torok]

WOW! Thanks everyone for your posts and information, I think my head exploded after I read the brief on the construction of the large scale guarded hot plate John Straube ‘ masters student is constructing. 
It really is fantastic to read all the different posts, opinions and scientific findings! I guess I will explain the reason for my inquiry ….(through my mate Lance), thanks Martin for getting the ball rolling.
I came across these bales that are "reconstructed" for export (probably same bales as John Glassford in 2001), and liked the fact that they are a consistent size and weight. They are a “manufactured" bale in that they are 8’x4’x4’ bales that are mechanically pulled apart and reassembled to a critical size and weight. This process for weight is controllable as it is in the best interest of the exporter to maximise the allowable weight being shipped in his container and to be able to consistently achieve this from bale to bale, pallet to pallet, and container to container. Consistency! consistency! consistency! 
The bales I have, came nicely assembled in a 6 bale assembly, 1200mm x 1000mm strapped together by PET plastic strapping, a nicely pre-formed half wall section that would only have a 240mm foot print (plus render or cladding) with undoubtedly load bearing capabilities at the 468kg/m3. The density of the bale allows for the resizing of bales accurately with a power saw/ band saw, I can screw into them, I have played around with ze cutting of ze strings as Tom Riven does to see what type of “resizing” of the bales would occur, if necessary to reduce density, or allow for better render penetration. The bales stopped moving approx 100mm (3”) increasing from 500 to 600mm. I have further compressed these bales between ply to create a uniform block using PET strapping….. 

So with all my playing with these bales I thought I would ask the question of what would the R value be of a SB of this density or of a wall system using these bales (render and bale)……so as to know if a wall system using these bales at 240 deep would be of insulative benefit over a standard construction wall….even at 3 times the possible 150 ish kg/m3 optimal density? I know I am simplifying the question to exclude things like type of render, thickness, type of straw, construction details, etc etc etc. 

Thanks everyone for your feedback!




Cheers Pete Torok
Earth Wood & Straw
0411 304 794