Sustainable Building Without Concrete

I have watched numerous videos about sustainable building practices. Most of them have the common element of using concrete to bond the walls together around such items as plastic bottles. Are there ways of attaching bottles or cans so you can forgo the concrete? While I think concrete is a great building element, I worry about the chemical reaction when it dries in the form of greenhouse gas emissions. Thanks.

There are probably as many green building techniques as there are green builders. Concrete is definitely not necessary for all of them there's cob, rammed earth, log homes, Wofati, tires, stone, and many more that I don't know about. Really depends on what you have, and what your goals are.

Brad Davies wrote:There are probably as many green building techniques as there are green builders. Concrete is definitely not necessary for all of them there's cob, rammed earth, log homes, Wofati, tires, stone, and many more that I don't know about. Really depends on what you have, and what your goals are.

AND WHERE YOU ARE!! No one method works for all weather or local conditions.

Generally speaking, you will need some kind of binder or reinforcement--concrete and/or steel are the common ones because of availability, longevity, and price. Green methods usually use considerably less of these materials, but they still need some.

Can a rammed earth tire be left exposed without a covering agent like concrete? I would assume that their shell would last longer than the inhabitants of the home.

I also worry about the idea of using plastic sheeting everywhere.

I believe the greenhouse emissions from concrete occur during the production, not during curing. doesn't mean concrete is great stuff, though.

there are plenty of options that don't use concrete. cob, compressed earth bricks, rammed earth, lime, stacked rock, straw bale. not all of those are compatible with using bottles, but rest assured that you don't have to use concrete if you don't want to.

A thought that runs through my mind at least once a day!

Cordwood building can be done with cob and many of the buildings have glass bottles incorporated in the walls so I would think it would work with plastic ones, especially if they have some sort of texture for the cob to key into. Perhaps doing some small test samples would be helpful?

My search in building without concrete lies in the foundation. I used a rubble trench foundation with a concrete beam on top for my straw bale house and if I had to do it over I would probably use earth bags on top instead. Then there are wooden pier foundations but I would think there would be a need of larger framing members for the floor if you were to put a lot of weight such as cob or straw bales on it. Any thoughts or experience in this aspect of building without using concrete?

For details, I remember The Hand Sculpted House having a section on foundations that incorporated alternatives to common concrete. Unfortunately I don't have access to my book right now, it's packed away in a box, and maybe someone else can chime in on the relevant points if they have the book.

As an architecture student, I can comfortably tell you that concrete is the only standard code compliant foundation material you can use without an engineer's specifications to bring to city hall now a days.

Nicola Marchi wrote:

As an architecture student, I can comfortably tell you that concrete is the only standard code compliant foundation material you can use without an engineer's specifications to bring to city hall now a days.

Luckily, or maybe not so, depending on how you look at it, I live in rural Vermont where my town has zero building codes; you just have to pay them the permit fees.


Thank you for pointing me towards The Hand Sculpted House. I've been looking for an excuse to add that one to my collection!

I love the book, and unfortunately it's caused me to doubt my own convictions about the modern role of architecture on a global scale. But, it's only the best books that make you question yourself.

Awesome about not having to worry about building codes though!

Rob Viglas wrote:Cordwood building can be done with cob and many of the buildings have glass bottles incorporated in the walls so I would think it would work with plastic ones, especially if they have some sort of texture for the cob to key into. Perhaps doing some small test samples would be helpful?

My search in building without concrete lies in the foundation. I used a rubble trench foundation with a concrete beam on top for my straw bale house and if I had to do it over I would probably use earth bags on top instead. Then there are wooden pier foundations but I would think there would be a need of larger framing members for the floor if you were to put a lot of weight such as cob or straw bales on it. Any thoughts or experience in this aspect of building without using concrete?

Go somewhere that plastic trash accumulates for a while - ie, not where it gets picked up.

Plastic bottles + sun + time = plastic shards, in my observation. At least some types may not even need sun to degrade with time - I recall moving some "stored bottled water for emergencies" out of a basement, most of which had cracked and leaked out of the plastic bottles in the course of no more than 4-5 years, while sitting quietly on a shelf in the dark basement. Stick to glass for wall-bottles. I've gotten past thinking they are neat (my initial reaction) with the opportunity to observe some up-close and personal over time, but IMHO is not IYHO.

Many alternative foundations only work well for a reasonable time in dry climates. You can minimize concrete use with a rubble trench and bond beam, but the only way to eliminate it (IME) that works well in wet places is the wooden post foundation or the treated wood wall foundation - and then you have rot or preservative issues, as well as drafts, frozen plumbing and animals under the house issues. Charred black locust posts might do if you can find a good source of large black locust. Works well for sheds without plumbing to deal with.

I suppose I am skipping over dry-laid stone, which is a drafty foundation and expensive, time consuming and not trivial to acquire the skill to do well enough to put a house on. In most parts of Vermont you should at least be able to find material without looking too far, though it may not be good material for the purpose. Glacially processed rocks don't stack well, on average. If you plaster it to keep the drafts and rodents down or build with mortar, you might as well have used concrete in the first place...and you might actually use a good bit less, as a rock wall needs to be a lot thicker than reinforced concrete.

Depending what you have (or what the glaciers left you) there is another alternative, as seen in the barn I grew up with - large glacial boulders under each post of a post and beam. Think of it as "guilt-free precast concrete" and also as something that will crush you if it gets a chance, so move them with care. With care, you'll live and it will work. They simply need to be of sufficient size to spread the load depending what your soil will bear, and get below frost (or be sited on drained rubble that does not frost heave, as in a rubble trench). Then you need wood for the beams that support the floors...

I have at times looked to both strawbale and cob (which turn out to be silly here where straw is an expensive import from far away) and compressed earth blocks - and in all three cases a concrete foundation to get them up off the ground was highly advised.

I guess I have read of someone using baled plastic bottles as a foundation, but given what I've seen of plastic bottles+time, I have doubts about that long-term, so I would not bet my house on it.

If you have time and opportunity, I think it's a great idea to build several small test structures (shed, chicken coop, well or spring house) using whatever schemes you are considering for the house before diving into the house with a technique you've read about, but not actually built and observed over time at your site.

L. Jones wrote:

Many alternative foundations only work well for a reasonable time in dry climates. You can minimize concrete use with a rubble trench and bond beam, but the only way to eliminate it (IME) that works well in wet places is the wooden post foundation or the treated wood wall foundation - and then you have rot or preservative issues, as well as drafts, frozen plumbing and animals under the house issues. Charred black locust posts might do if you can find a good source of large black locust. Works well for sheds without plumbing to deal with.

I suppose I am skipping over dry-laid stone, which is a drafty foundation and expensive, time consuming and not trivial to acquire the skill to do well enough to put a house on. In most parts of Vermont you should at least be able to find material without looking too far, though it may not be good material for the purpose. Glacially processed rocks don't stack well, on average. If you plaster it to keep the drafts and rodents down or build with mortar, you might as well have used concrete in the first place...and you might actually use a good bit less, as a rock wall needs to be a lot thicker than reinforced concrete.

Depending what you have (or what the glaciers left you) there is another alternative, as seen in the barn I grew up with - large glacial boulders under each post of a post and beam. Think of it as "guilt-free precast concrete" and also as something that will crush you if it gets a chance, so move them with care. With care, you'll live and it will work. They simply need to be of sufficient size to spread the load depending what your soil will bear, and get below frost (or be sited on drained rubble that does not frost heave, as in a rubble trench). Then you need wood for the beams that support the floors...

I have at times looked to both strawbale and cob (which turn out to be silly here where straw is an expensive import from far away) and compressed earth blocks - and in all three cases a concrete foundation to get them up off the ground was highly advised.

I guess I have read of someone using baled plastic bottles as a foundation, but given what I've seen of plastic bottles+time, I have doubts about that long-term, so I would not bet my house on it.

If you have time and opportunity, I think it's a great idea to build several small test structures (shed, chicken coop, well or spring house) using whatever schemes you are considering for the house before diving into the house with a technique you've read about, but not actually built and observed over time at your site.

Makes sense about the plastic becoming brittle but I wonder if it depends on the type of plastic? I was just trying to help out the OP not trying to use plastic bottles myself, especially in a foundation!

I've thought about those other foundations and agree with you on the use of dry laid stone and treated piers. The charred locust has been an idea as well and is still a potential for me as the next thing I build will be a pottery studio and not residential so the animals and drafts are not that big of a concern. I do think that a rubble trench with gravel filled earthbags acting as the bond beam would eliminate the need for concrete.

Interesting that you found the straw to be expensive and only available at a distance. I'm in SW Vermont and was able to find bales within several miles and weren't expensive at all.

Yeah, I'm not sure about the baled plastic for a foundation either!

Thanks for the input!

Straw is certainly available, but AFAIK it has been hauled in from somewhere that grain is actually grown, and as such costs more than hay - IIRC 5-6 bucks a bale for straw (a byproduct with no food value) when 3-4 bucks would get you good quality hay you can actually feed to animals. To me, that's expensive. If you've got $1-2 straw in SW Vermont, do tell me where, I can hit the border in 5 minutes drive. Strawbale was at least partly driven by the situation in some grain producing regions where the straw was burned as being not worth hauling away - compared to that, 5 bucks a bale is astronomical...but given how far it travels, makes some sense.

Considering what a bond beam does, I don't think earthbags do it. I don't see either tensile strength or spreading the loads from a bag-o-dirt. Perhaps I lack vision.

There is a lot of rye and oat straw grown right around here. As a matter of fact there were two fields of rye growing just down the road while I was building our frame. I had hoped to use it for my house but the farmer's baler was beat and couldn't compress the bales enough. He's since got a new baler and is planning on doing more straw this year, lucky me! I could find out the cost when it becomes available if your interested.

I don't remember exactly what we paid per bale, I'm thinking $3-4. Definitely not the $1-2 cost of hay! But still our house is under 1000 sqft and the south facing wall is mostly glass so we didn't require a ton of bales. I also know that all the "horse people" around here drive up the cost of good quality straw, only the best for their horses! I am also considering using hay bales for our studio due to the cost and also just for some experimentation/comparison fun. Heck, the author of Serious Straw Bale lives in a hay bale house somewhere down near you I believe. Sure the hay doesn't insulate as well but properly designed, sited and sized I would think it should do alright especially with the reduced cost factored in.


I just purchased/downloaded Owen Geiger's earthbag building book and he specifically talks about using gravel filled bags as an alternative to a concrete bond beam on top of a rubble trench foundation. His book touts being "engineer approved" if that holds any weight, does for me. I've also come across the idea in other natural building books and websites. Tying a wall system such straw bales into the bags is something I do need to research more...

My apologies, Lee for taking over the thread for a bit! I am wondering what your plans or ideas are as far as using the bottles and cans in a wall?

Rob,

I have watched numerous videos on green architecture, but most of them still rely on non sustainable elements like plastic sheeting to create vapor barriers. And I also heard that the emissions for drying concrete are so much that they are actually one of the top producers of green house gases. So I was just curious about people still being able to make earth ships and the like without plastic, etc.

Lee Morgan wrote:And I also heard that the emissions for drying concrete are so much that they are actually one of the top producers of green house gases.

nope.

the emissions occur during manufacture. when calcium carbonate is kilned to make lime for cement, carbon dioxide is released. the energy to do the kilning also typically involves producing carbon dioxide. but that's during manufacture, not during the cure/dry.

some lime mortars absorb the carbon dioxide that was released during kilning as they cure, but that still leaves the carbon dioxide released to produce the heat for kilning.

Lee Morgan wrote:http://www.youtube.com/watch?v=BdG0s8llQrA

I believe that he's right about the percentage of carbon dioxide that concrete accounts for, but that he's mixed up about when the emissions occur.

Portland cement is largely calcium silicates. there's oxygen in there, but no carbon. thus no way for it to evolve carbon dioxide during curing. to make concrete, sand and water are added to Portland cement. still no carbon there.

I guess that what's important is how much carbon dioxide is created to use concrete, not at what point in the process that occurs. it's better for credibility for us to get our facts straight, though.

Lee Morgan wrote:Can a rammed earth tire be left exposed without a covering agent like concrete? I would assume that their shell would last longer than the inhabitants of the home.

I also worry about the idea of using plastic sheeting everywhere.

No. You should cover the tires. The rubber will off-gas for years. Ever been tire shopping. Unless you enjoy that smell, I wouldn't leave it uncovered (even if not in a living area)

Hello to all,  I am new to this way of communicating, so please forgive the occasional dumb question. I'm not sure if this is the best thread to post my questions, but here I go. Here in northern NSW, AU, my lady and I are building a two story, round-wood, post and beam, circular building (similar to a grain silo) with straw bale infill walls, clay/lime render skins and an earthen floor with PEX radiant heating and hardwood inlays. I am 40 years a painter and plasterer with a fair bit of construction knowledge. I also spent 30 years of my adult life in a religiously constricted, Judeo-Christian, share everything and own nothing community, which I departed about 5 years ago. It was a profoundly beautiful way of life in many ways, but having gained a sort of PhD in narrow-mindedness, I'm now like a kid in a candy store of new ideas and ways to embrace life. I too see that building a home is not rocket science and that we should look to ourselves first for answers, but having said that, good, sound advice is a lovely and comforting thing. We are also choosing to spend as little, and be as resourceful as humanly possible. And, sorry about the metric measurements; I'm originally from the U.S., but I've fallen in love with millimeters.
 
So... my concern is foundations. The site is gently sloping; the soil is sandy loam. I've carved out a flat pad with our farm tractor, digging into the high side and moving that soil to the lower side. I'm going to hire a plate compactor and pound the filled side for a loong time. The winters here are incredibly mild and frost is not an issue. I'm from Wisconsin where people have basements and central heating. Not here. Termites (white ants) are a definite problem though. Our 40 acres is largely regrowth Aussie hardwood, but lacking in the tallowoods and grey gums, etc... that one would chose to be near or in the ground. I see the sense in using concrete under buildings, but I'd really rather not, and we can't get a concrete truck down to the site anyway. We are on a creek with an endless supply of smooth river rock in all sizes. We also have an elegant stand of flooded gums (eucalyptus grandis), tall and straight as ships masts.  Fine for framing, floors and external features, but not durable in the ground. I want this building to be there in a hundred years, so I understand that I need to get down to stable soil for a start.
 
My idea is this:  Fire up my trusty earth auger and drill a series of 250mm wide holes around the perimeter at around 1200mm deep, maybe up to 2 meters deep on the lower, filled side. Fill the compacted bottom of each hole with 200mm of clean stone. Then weld a thick steel base plate onto the end of a galvanized, 100 x 100 x 4mm square hollow steel section. Being a painter, I would coat each SHS with many coats of serious anti-corrosion paint. Then place each one onto it's stony pad, level up and back-fill with more clean stone. These steel posts would protrude above ground level to the height of the coming grade beam. Then I plan to dig and fill a rubble trench between each of these in-ground posts. The top of that trench brings us up to grade. Then we lay 2 or 3 courses of rock-filled, barbed wire reinforced earth bags to form a grade beam. That done, I would bolt my heavily preserved, flooded gum posts onto standoff stirrups welded to the top of each steel pier. Then I would build a strong upper ring beam to lock the timber posts into position at the top. Back at the base, I would construct a timber, ladder-type stem wall for the straw bales to rest on. This would, of course, be bolted to the timber posts as well, tying it all together.  I would then go back to the top and construct the roof before installing the straw bale infill, etc...

In all I've read, I haven't seen this method described, and of course I ask myself why. Am I missing something? Or maybe it is fundamentally sound, but needs some help here and there. Any comment or ideas would be greatly appreciated.   Have a creative day....

Here is a really cool video about making lime from shells. He builds a natural kiln using just long grass and clay, and burns the shells. Then he slakes the shells and magically makes lime! This is an introductory video. He has a much more involved video here. But this is a great introduction.

I have the urge to experiment! But not today - it's snowing.

Enjoy!

That tabby ! Someone mentioned it on another thread, so I did some reading up on it. The idea is fascinating. I wonder if someone locally could collect shells as a waste product from restaurants for example, locally sourcing it if one lives near the ocean, in sufficient quantities to make good lime.

Things converge, I was originally interested in rammed earth as an alternative to masonry, but ended up re-examining stone and concrete, slipforming stone masonry, and then lime, whence I stumbled on this cool thread.

Reading about Tabby, it seems to have been very common in the South and the more I read up, it seemed to be based on Spanish and Portuguese lime-based Tapia. Which is probably why it pops up in places like the Carolinas and Georgia.

In turn, Tapia seemed to be based on Moorish, Arab-Berber,  vernacular practices in North Africa. A variant of rammed earth using lime and gypsum rich soil to make a much harder, more stone like, product than normal rammed earth can give..

One thing that suggests this is the use of the word Tabiya in Algeria, my wife's country of origin, and Tabut in Morocco, the homeland of the Moors. Words ending in -a or -t are often feminine in Arabic, the letter that can be rendered as an "A" when a word is transliterated into a Romance or Germanic language is called "ta marbuta" it's a variant of the Arabic letter 'ta' which is cognate with our Latin "T" but in come contexts can be pronounced like an -a, an -ah, or a -t

Which makes me thing "Tabut" is a Moroccan variant of the original word that the Arabic Tabiya, and Spanish Tapia, and the American Tabby, all came from...

Tabby in the Coastal Southeast: the Culture History of an American Building Material.
http://digitalcommons.lsu.edu/gradschool_disstheses/3205/

This is interesting:
Notes on 'Tapia Walls' in Seville (Spain) during the 16th Century in the ...
http://www.arct.cam.ac.uk/Downloads/ichs/vol-2-1375-1386-graciani.pdf

The valencian rammed-earth wall (“tapia valenciana”) in the restoration of Alaquàs Castle
http://tapiabrick.blogs.upv.es/files/2014/02/067.pdf

Late Medieval Castles Built with Rammed Earth in Castile, Spain
http://ascelibrary.org/doi/full/10.1061/(ASCE)AE.1943-5568.0000259

Late medieval rammed earth technique in the fortifications of Castile, Spain.
https://www.academia.edu/13173151/Late_medieval_rammed_earth_techniquein_the_fortifications_of_Castile_Spain

Earth construction in Algeria between tradition and modernity
https://dspace.lboro.ac.uk/dspace-jspui/bitstream/2134/20750/3/jcoma.15.00048.pdf

edited by moderator to fix link

Does talking your own lime produce less pollution?
Transportation of the finished product is removed,but otherwise,it does not seem like an improvement.

William, those are thought provoking questions and they leave me in a quandary.

Chen how is the project going?
I am concerned the termites will get to your hardwood despite your best efforts?

I think concrete get's a bad rap.  Sure making cement produces CO2, then again making most thing produces CO2.  The reason cement produces so much CO2 world wide is that they use so much of it building things like bridges, and damns, roads, skyscrapers, etc.  Using it for projects around the home doesn't make any significant impact.

Producing enough cement to make 11 cubic meters of concrete creates roughly the same amount of CO2 as the average car produces in a year, from just burning the fuel.
Used wisely that concrete structure will still be around in 50-100 years.

The above ignores the CO2 produced to manufacture the car which from what I read is roughly the same as all the CO2 produced from driving the car over it's typical lifespan.

With many building materials, transporting them accounts for a sgnificant percentage of their CO2 foot print.
Considering that, it seems to me that the best building materials would be the ones locally available.

Where I live the most abundant natural materials are sand and rocks.  The easiest way to build anything with sand and rocks is to turn them into concrete.

Paul, I think you are on the money!
As a practising Engineer, I always talked people through alternatives and the real impact of what they had in mind.
Local materials and cement from wherever it comes from, compared with high technology materials from afar.
Concrete or timber that will either rot or be eaten by termites as happens where I frequent.
I use a lot of second hand stuff, but it does take time to find and reuse compared with new material, but that is where size of home comes in.
Huge home or adequate sized home.

Adequate sized home usually takes less time to build and second hand materials can be ultilizedif they are wanted.