Hi there!
My apologies for letting this horse die and then kicking it
It was indeed my idea to create the stuctural walls out of gabion meshing, then finish the roof off using superadobe domes or vaults. Because the cheapest and most widely available material that could become a gabion is a rebar wiremesh, the layouts I am playing with in my mind are using straight lines. I know rebar could in theory do curves, but my knowledge of structural integretity is too small to actually go into it and do domes/curved walls with confidence. I was thinking along the lines of a Hogan, an
Oehler structure or a wofati shaped building. Keeping the wall sections to the standard size of wiremesh (what is it, 2 by 3 meters?) seems logical to me. If my research proves me right, you can do hectagonal and octagonal (sp?) domes using superadobe. Or transition from octagonal into a circle into a dome.
I have a few questions to
answer and also to ask. First by Andrew Parker:
Getting back to gabions and liners, here are some questions:
What is the expected life of a geotextile liner?
Anything that is made out of polyethyleen or epdm can be expected to last indefinetely as long as it is not exposed to UV radiation. On the outside of the gabion this would be a minor problem as it would end up covered in dirt. On the inside it might create trouble for any kind of render to stick, it is a matter of what fabric is used and what kind of render you're trying to apply. My experience with lime plaster tells me that it could be alright to render a rough fabric, but anything close to earthbag/superadobe might need a basecoat of something else first (
cob?). But to be honest, my experience comes from rendering cob and straw, not superadobe like fabrics.
Would the gabion and liner stand up to the soil being compacted?
As long as you're not trying to compact it with one of those compactors used in paving sidewalks I think you'd be fine. The video posted below is of someone making a compressed earth wall using one of those machines and they were using a system normally used to pour concrete to prevent the sides of the wall from buckling. So I assume that just using rebar mesh would allow too much play for more than regular compaction.
Could you use foamed loam in a lined gabion arch or dome?
To be honest, I have no idea about this exactly. The main reason for me to think without the use of foam insulation is that I expect to be too warm in Greece. Insulation might seem like something one would want in a colder climate, but with summer temps going up to 50C and winter temps staying around 5C I expect that we will need no insulation (Athens dipped 1 or 2 times below freezing this whole winter). The 17C underground temperatures that Oehler talks about seem like a perfectly adequate temperature for living year round.
What would be the best way to seal the surface of a stone filled gabion? I recognize that some would want to preserve the aesthetic of the stone face, but without grout or mortar, it makes a great hideout for vermin. I suppose you could do a kind of slipform stone masonry, using the gabion as a sacrificial form, or put a veneer over the gabion.
My first impulse is to go with Oehler's and Wheaton's design. Which is simply to leave the structural material to be exposed. I actually look forward to seeing the combination of rusty metal and raw stone. If one would choose to go for a smaller sized stone though, a fabric might be needed to contain it in the larger rebar mesh structure. If that's the case, a lime plaster seems in order. Grass or another kind of locally abundant material could be added as a layer between the geotextile and the rebar to provide a good hold for the plaster? I've also considered the use of carpet... carpet is one of those impossible to repurpose/recycle waste materials that might be around in copious amounts. If added between the rebar and the geotextile, it might make a nice baselayer for a plaster. It might also be a good candidate for protecting the polyethyleen from being punctured.
Another option I have considered, provided there is adequate natural light in the house, is to grow Ivy (Hedra Helix) on the walls. Or any other kind of shadeloving evergreen that is. The nice thing would be that you end up living in a completely leafy nest. The nasty thing is that a plant covering your walls and roof might make quite a mess inside. Airquallity inside the house should be amazing!
About the vermin. I expect to live with vermin, it is simply a fact of life in my opinion... keeping apropriate colleagues (pets) around and making sure there is no food exposed, should reduce their nuisance level to a minimum. Walls of any kind are a niche that is utilized as living quarters, I don't presume layers and layers of mortar will stop anyone from living there.... But that's my two cents. Also, I'm not bothered too much by
mice or birds or
bats, I think of it as a blessing to have other creatures joining me in 'my' house. Right now there's a Robin nesting in my strawbale walls
My own questions come down to these:
Tom Taber, in your post you speak about a geogrid being placed between layers... what do you mean with that? And on a related note... what is a deadman brace?
Also, considering superadobe and its related forms might make the strucure deviate too much from the original wofati design. What about just using gabions for the walls and then finishing the roof off with regular woodland materials?
OR, if you were to have access to copious amounts of other materials, some other kind of roofing material. I've been thinking of shipping containers. I know that in large parts of the world shipping containers are simply left and sold off for scrap metal prices (sometimes even given away, though that might be changing). I could imagine stripping the corrogated metal sides from the containers and using them as a roofing material. And perhaps the beams that are left over as horizontal roof supports? Like I said, my knowledge of engineering is limited, but I can imagine that it is a very easily recycled building material and if properly supported it should last generations. It would not need to be watertight, just able to support the weight of some soil (I believe 18 inches is what I've heard mention).
http://www.panamashippingcontainerhouse.com/cutting-metal-making-a-wall
Your thoughts?