[GSBN] vaulted straw bale house

RT ArchiLogic at yahoo.ca
Wed May 27 18:29:12 CDT 2015

As an archisort, arches and vaults hold a special appeal but I've only  
built them using masonry so have no real empirical knowledge to add to a  
discussion about building a SB vault.

Other than the challenges of building a structure which relies entirely  
upon compression to work, using infinitely compressible SB building blocks  
(which one assumes that the builders have already addressed by providing  
some sort of integrated exo-skeletal or auxiliary structure in their  
proposal) the other biggest issue is providing an effective strategy to  
keep the bales dry ... both during and after erection of the vault.

The two farmer friends (2FF) appear to have addressed at least one third  
of the "keeping it dry" issue with the greenhouse over-roof and another  
1/3 by proposing an additional timber-framed structure over the bale vault  
with a conventional roof/cladding,

While the greenhouse *may* do the job of keeping the bales dry if it  
doesn't leak (something which greenhouses are notorious at doing) I think  
that it would be Hell for the people having to work inside of it during  
the hot & humid NE US summer in the era of Changed Climate weather  
extremes ... and I do mean the biblical Hell.

There is also the issue of that period mentioned only in passing but a  
critical one nonetheless --between dismantling of the greenhouse over-roof  
shelter and installation of the cladding on the wood-framed structure over  
the bale vault.

As the former Albequirky Derelict mentioned about heart-ache always  
potentially just being ready to to strike with vaulted SB projects, I  
would imagine that even a pious monk who took an oath of silence would  
loudly vocalise more than a few expletives if after having spent a  
torturous summer being broiled inside of a greenhouse while schlepping  
bales awkwardly overhead ... and then all of one's winter working on  
finishing the interior ... only to have a sudden early Spring rain storm  
thoroughly soak the bales in that brief period between greenhouse  
deconstruction and roof cladding installation.

Perhaps a better approach may be to simply focus on building the proposed  
conventional wood-frame structure first, and then once it's weather-tight,  
insert the bale vault as an infill afterwards. If a sheet metal roof  
cladding over open purlins is used, it would be a relatively simple matter  
to de-mount individual roofing panels as needed to accommodate any futzing  
 from overhead, if and when access to the top side of the bales is needed  
and have the panels readily at hand to re-install if a sudden rain is  

Better yet, the 2FF might consider ditching the redundant wood-frame  
structure altogether and use a pre-fab deep "Vee" rib corrugated  
galvanised steel arch shell as the combined permanent roof cladding and  
structure, erected first, using it as the support from which an interior  
bale vault can be suspended using the already existing suspension system  
that are designed for conventional insulation and interior sheathing.

The "Vee" ribs would also provide a built-in ventilation airspace over the  
vaulted bale insulation to ensure that any bulk moisture intrusion into  
the insulation as a result of a less-than-effective air barrier strategy,  
would have a means to get out.

If the quonset shed exterior aesthetic is less than appealing to the 2FF  
(or their families (3FF) then I would imagine it wouldn't be too difficult  
to simply tell the engineers (typically provided free by the steel arch  
building manufacturer, in Canada at least) that the intention is to  
install a Living Green Roof over top and they can design the steel vault  

=== * ===
Rob Tom            ADT1
Kanata, Ontario, Canada

[from GSBN Digest Vol 42, Issue 9]
> On Apr 15, 2015, at 10:53 PM,  
> ejgeorge at riseup.net<mailto:ejgeorge at riseup.net> wrote:

[snipped & pasted  -full message available in GSBN archive somewhere on  
the WWWeb, pester megamulti-ListMom Wild Bill-Bob Christensen for the URL ]

> Some local (northeast US) farmer friends ... trying to build a vaulted  
> straw bale house this summer.

> -- mostly exterior timber frame  ...conventional roof above the vaulted  
> bales

> Likely only the vaulted roof would be in place over the winter, 
> conventional one added after greenhouse is dissembled in the spring.

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