[GSBN] Jumbo Bale Question

[John Glassford]

G ' day Martin

Thanks mate and we do love building wineries!  Made some good mates in
the wine business now.

> I'd like to understand this better.  Do you have documentation of your
> render creep tests?

Yes I do and will send you a copy.

>
> However, John, even if the render creeps away from the top plate (thus
> eliminating direct transfer of roof load to render) it's likely the render
> is still carrying most or all of the load.  It is transferred into the
> render through the straw instead.  At least I think.

Not sure as I do not see how the render can carry any load after it
has creeped down and broken the bond between the top plate and itself.

>
> I suppose it's possible the load bypasses the render and goes straight
> through the straw to the foundation (especially with dense jumbo bales).

More than likely.

> But for this to happen the straw would compress immediately or over time,
> whereas the stiffer renders would not compress, and there would presumably
> be tearing at the straw-to-render bond.  (Maybe that happens within
> acceptable limits?)  The dynamic depends on when the wall was loaded, when
> the render was applied, how stiff the render is, and how dense and
> pre-compressed the bales are.

That is why we like the all thread so much as you can get great
compression even on jumbo bales.  Jumbo bales do not compress anywhere
as much as standard bales. on edge or on their flat jumbo bales are
much more dense than two string bales.

>
> I think this is an important question.  What really happens in load bearing
> walls, and what factors affect what happens.  That is, what are the actual
> load paths.  Although I generally still believe the renders carry the loads,
> maybe this needs to be reinvestigated/rethought.  Especially with certain
> wall systems, or roof-to-wall connections.

Again for two string bales like the hybrid method as we get great
compression with the all thread and then we lock the window and door
frames into the top plate.  We have also used this method with jumbo
bales.  The hybrid I mean as we call it.

The reason I can see the creep in a finished wall is that the ladder
top plates we use are wider than the bales by 50mm or 2" on each side
of the wall so we create a render point for screeding. The render
moves after a while and you can see the crack easily on most
occasions. The bottom plates are a mirrior image of the top plates so
we can screed top to bottom and get a reasonable straight finish.
Then we are able to fix skirts to the bottom plates and cornice to the
top plates that hides the creep crack.

Kind regards
John Glassford
Huff 'n' Puff Constructions
http://www.glassford.com.au
61 2 6927 6027
In Australia (02) 6927 6027

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