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! the first wofati - allerton abbey- version 0.7

 
pollinator
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Location: Chicago/San Francisco
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> hold sticks against pole until backfill...

Idea:

Put a 3rd (weaker, not set deep) working pole (just to aid construction) _outside_ the sticks and in the middle between the structural poles; place the working pole such that the fattest stick can be laid against the two structural poles and just kiss the working pole on the outside edge of the stick. "Fill" the wall by laying sticks against the two structural poles as usual but "inside" the working pole which holds the stack of sticks against the two structural poles to form the wall. This might also accommodate the numerous small infill sticks shown in Paul's drawing if they're long enough. Since the third post (in this case) is a construction aid, it doesn't need to last long; it can be installed quicker by embedding it only slightly and/or diagonally bracing it's top toward the new wall just strongly enough to contain the stack of sticks/infill for the wall until backfill is placed.

Pros- This might be simple and strong enough to be fast w/out sacrificing wall integrity.

Cons- There might be risk of damaging the inner membrane where it is laid over the working pole. Perhaps this could be helped by using a specially smooth working pole, eg. 1" EMT, which gets withdrawn during backfill and reused (thus justifying the time/expense of the extra smooth pole); or protecting the membrane with some kind of "chafing gear" like strips of old carpet between the working pole the and membrane which would also allow the working pole to remain in place permanently and avoid the need and effort to withdraw it during backfill.

edit: I think the working pole has to remain in place - I can't think of a way to withdraw it because the membrane needs to be in place before backfill.

I doubt that the screws increase the spanning strength of the sticks to any large degree; if the stick wall is going to bow in it will do it screws or no. The mechanical advantage of applying force perpendicular to a (semi) flexible span between two end points connected to the span creates such a huge tension to draw the end points together that if the stick wants to deflect, it probably will. Either it will bend the fasteners, elongate the fastener holes or pull the end points closer or all three. Putting a third structural pole in the center of the original span will halve the span and of course that will greatly reduce any deflection of the stick.


Rufus
 
master steward
Posts: 28610
Location: missoula, montana (zone 4)
hugelkultur trees chicken wofati bee woodworking
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I think the third pole on the inside is providing structural integrity. We don't want the stick to bow into the room.

But I do get what you are saying. With something on the outside we can slap a lot more sticks into place much faster - as long as we are able to pull that out later. Maybe the thing to do is have something that is only two feet tall or so. We can place a lot of sticks and then as we backfill, we lift this "form".

 
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Location: Kansas Zone 6a
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I don't think it needs to be a pole, a 1x or sawmill slab would be enough to hold them there and shouldn't endanger the barrier.
 
pollinator
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Location: E Washington steppe
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Although it's still a purchased item, tie-wire (such as used to tie rebar for concrete) would secure your horizontal poles to the posts and ought to be way cheaper than screws. Starting at the bottom, each successive course of poles would be supported from below and the tie-wire would merely have to hold the poles to the posts. Also should take about the same time to install as screws once you got the hang of it. Be sure to tuck the twisted ends away from the plastic sheeting.
= )

obtw, excellent work on this first wofati! I've been on the edge of my seat hoping your team would get done before the real cold hits.
 
pollinator
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Location: Vancouver Island
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Ok, So it has been in use for a bit now. How it goes?

I recall someone said the earth berm was rather cool and that was expected to make the performance not so good. How has it been? I would think that even cool the earth was 50F or so... did any one measure? I would think it is easier to heat from 50F to comfortable than from 30F to comfortable The logs will still provide some insulating too.

So how is the wood use? What life style changes have been made? Have those changes seemed good or not? What temperature is being maintained inside? Is it warm or cool subjectively? Does one's back feel cold when the back faces the window? when one's back faces the logs?
 
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paul wheaton wrote:
569) We spent over a thousand dollars attaching the last layer of wood. I passionately want to get the cost of materials for the shell to fall under $200. So this needs to be dramatically reduced or eliminated. Starting by looking at one wall: there are two poles holding up about 30 sticks. Each stick has two, rather expensive, screws holding it in place. I want to replace that with zero screws. Let the pressure of the dirt hold it in place. I do have a concern that in this case there could be bowing of the sticks - so I propose adding a pole in the middle to prevent that.


I know the round wood spans farther and looks good, but maybe this is good reason to go back to milled lumber. Then you can use nails or drywall screws.
 
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Hi Paul,

Sorry for not getting back to this post before now. I will use your list of "that I want to do better next time:"

569) Attachment methods:

To answer your question towards Miles about hogans, "What would I gain?" Geometric strength in design with traditional joinery methods and an alteration in material dimensions. On the note of traditional joinery, that would be a good way to avoid those expensive fasteners. For your cladding logs, they could be pegged on, lashed on, or even sewn on (of a fashion), but of these lashing would be the fastest, with pegging a close second. Your idea of having the mass of the earth hold things in place is possible, but should there even be a small seismic event this could lead to catastrophic fails without the monolithic attachments of some type, either traditional or modern. I definitely agree you can lessen the financial out lay in fasteners.

570) Blocking view of wrapping material:

From grass reeds, to a good cob layer (maybe augmented with lime) or even clay chip or clay straw, (which would add an insulative layer) would all be good alternatives. There are others but these are the first that came to mind, that also seemed like the best. Others include, cardboard, new paper, paper, recycled carpet (nice 100mm to 200mm thick layer of it), etc.


571) Wings:

Not flaring the wings sounds like a good idea, and would make your joinery easier to facilitate.


572) Bark:

Hmm, well that could work, and yes the bark could (or might fall off depending on species of conifer) but you could also get a really healthy infestation of stag horned beetles (or related Cleopatra ssp) as well and that would not be recommended considering the load these wood members take, including the cladding logs.

573) Earth layer:

I agree the dryer the better.

Any other ideas?

Yes, a big one for me is not burying your post in the ground, but creating a sill or knee wall assembly that the frame work would be attached to or part of. I can think of several methods all strong enough to take the lateral shear loads and moment connective loads from the back fill. Perhaps even a "boxing" method that would include a wood floor system that could facilitate easy access to plumbing and wiring should you choose to have it. My main reason for getting the wood isolated from direct contact with earth is potential for infestation of termites into the frame assembly, as well as extending the life span of your architecture.

Since you have the mill, perhaps flattened or planked wood and some timber framing? I had a really big thing for "mine timber work" as a kid and really study obsessively the different methods of doing timber work in mines for shoring and and strengthening wall systems. You get that wood isolated from the earth, upgrade the layering system to really have some redundancy and I think you could build something that would easily last multiple generations. I also think there is a book in this concept and modeling of yours...would love to write it someday.

Warm Regards,

j
 
Bill Kearns
pollinator
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Perhaps closer to the entryway you envision?
 
paul wheaton
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Location: missoula, montana (zone 4)
hugelkultur trees chicken wofati bee woodworking
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Bill Kearns wrote:

Perhaps closer to the entryway you envision?



Bill, I thought your place was drier than that!

Please tell me more about this pic!
 
Jay C. White Cloud
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Yes Bill, please more info? It looks like either the "male" style of a Dine' Hogan, or one of the Athapaskan native structures, which would be the model I would follow and adapt to current living styles.
 
this is supposed to be a surprise, but it smells like a tiny ad:
Heat your home with the twigs that naturally fall of the trees in your yard
http://woodheat.net
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