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Monolithic Dome

 
                      
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The majority of the planet has soil that will work for earthbags.  There are numerous examples of people who have built shells for under $10/sf.  The bags can be had for $.06 each online or locally.



While you may get bags for under a dine, that doesn't mean that you can get the fill cheap. As I stated, I can't walk outside the door of my home and get the fill. So that means having it transported to the site at a cost as well as the cost for the fill. So house much energy is wasted on transport. That means the walls can't be built for $10 a sq ft. If I can't do the labor then I need to have someone do it. So there is another cost (which is already included with the MD). For one person to build these earthbag homes especially after the building gets over a certain height would be difficult.

Where do you get the 5,000 psi concrete in a city?  Is it cheaper than dirt?


I call the concrete place. I can get 5000 psi concrete anytime I want it. No it's not cheaper than dirt. However not all cases is the material for your bags free.

Only if you ignore the immense amount of energy in the materials and processing to make the MD.  What is the EROI for an MD?


What does that have to do with sustainability? Yes there is a cost for concrete but the life of the MD is measured in centuries not decades. So what's your point? So how do you calculate the EROI of a building that is very energy efficient when it comes to heating and cooling? Also a building that requires very little maintenance as well as lasts the life time of many generations.

Most adobe houses in my area are several hundred years old, and I rarely see them much above or below 75 degrees F.


There are few if any adobe homes in the north Texas area. Also, the humidity is high most of the year. Thermal mass works well however, you have to watch to make sure the walls don't cause condensation. As for a MD they utilized building practices that minimize condensations. Not sure for the earthbag homes.

The bottom line is that concrete is not a sustainable, energy efficient solution to most owner-builder construction projects.



This is not true. Concrete has been around for hundreds of years. Some countries don't use wood for their structures because of sustainability (Germany). They utilize concrete for bulk of the building. These building last for many years. I will have to differ with you on energy efficient buildings. The MD is very energy efficient. There are many MD's in the areas but I haven't found one earthbag home. I can go see a few earth ships but that's a different method.

There is no reason they can't last as long as any MD in the same conditions.


This is to be seen. Since I can't visit or see any in my area and MD's have only been around since the late 50's or early sixty's the jury is still out.
 
                      
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BTW for you Earthbag folks. Take a look at the following vid of a guy here in Texas building one of these things. Note all the comments on how hard it is to build and that you should be well versed in this methodology before taking on this type of project. Also, he speaks of the unexpected costs.

http://www.tinyhousedesign.com/2011/05/26/earthbag-home-update/comment-page-1/#comment-19336

So much for a cheap and easy building system. As I stated with enough cheap labor and free or nearly free materials one could build this type of home. I would rather trust the guys at MD to build it for a few more bucks a sq ft. I would have a better built and more energy efficient structure in the end.
 
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MD to build it for a few more bucks a sq ft

$50/sf more, minimum.  That's thousands of $$$ on the cost of a house.

So much for a cheap and easy building system. As I stated with enough cheap labor and free or nearly free materials one could build this type of home.


You might want to look at examples of the many homes built worldwide.  Here's a good start: http://earthbagbuilding.wordpress.com

By the way, I never said one person could do 200 sf in a day.  A 3 man crew (low skill, less $$$) can do 200 sf in a day.  Most new builders average 10 sf of wall per person per hour.

As I stated, I can't walk outside the door of my home and get the fill.

Most owner/builders can. Local sources of cheap fill can be found everywhere.

What does that have to do with sustainability?


Energy spent on building materials is very important when your industry (concrete) consumes large amounts of fossil fuels and produces large amounts of pollutants.

Yes there is a cost for concrete but the life of the MD is measured in centuries not decades.

Can you give us a link to an example of a MD that is a century old?

This is not true. Concrete has been around for hundreds of years.

That doesn't mean it is sustainable. Fossil fuels have been around for centuries, too.

Concrete consumes large amounts of energy to produce, ship, and use. It is a significant source of CO2 emissions.

This is to be seen. Since I can't visit or see any in my area and MD's have only been around since the late 50's or early sixty's the jury is still out.


Earthbags don't differ much from traditional rammed earth, which there are many long-lasting examples.

Here's a structure that is thousands of years old that scientists believe was made from earthbags:
http://earthbagbuilding.wordpress.com/2011/05/31/earthbag-building-may-be-thousands-of-years-old/


 
                      
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Yes there is a cost for concrete but the life of the MD is measured in centuries not decades.
Can you give us a link to an example of a MD that is a century old?



I never said there are MD's centuries old but that their life could be measured in centuries not decades. I can state caves that are thousands of years old but wouldn't want to live in one (even though folks did).

Earthbags require certain mixes of material to work best. Also, a lot of labor. Almost all the examples I've seen on you tube are of whole groups building an earthbag home. Also, take a look at the Cal Earth class that was recently held in Austin TX. Nothing but troubles. Again an MD can be built anywhere anytime. It has a standard process and doesn't require as much fussing as the earthbag system. Just facts.....
 
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Timby have you taken the MD course is Texas, I've watched the  video dvd course over and over, and I just don't think it's enough for me to do them on my own. In places where nobody knows about MD's that pretty much makes the client the on site forman.  I watched a great video on youtube of a lady in Hawaii who built her own, day in and day out. The only thing she imported was some men to do the shockcrete. They went overboard and layed it on inch and a half thick and it collapsed.  What really made her a tough cooky is she kicked them off the job and hand troweled it in the end. That video is what made me know a graphic artist turn gallant maverick buccaneer can do this.
 
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'found this on a google search about using concrete as a building material: Concrete is a familiar substance. Its durable nature and versatile applications have made its usage ubiquitous throughout our cities. However this primary building material is also extremely energy intensive to make and transport, and produces a significant amount of the world’s greenhouse gas emissions.

It seems a better solution to build a timber frame dwelling and fill in the walls with Hempcrete which is just lime and hemp hurds mixed although trees are still cut down much less wood is used.  It is relative easy to learn and it is far more energy efficient from both the standpoint of the carbon sequestered by growing the hemp and then using the waste from processing the fiber to build a place to live.  That makes it carbon negative.  Using concrete is not the best choice for building.  There are hundreds of examples of hemp/lime construction that the Romans built all over Europe.  I am currently testing using hemp fiberboard to construct laminated "timbers" to test for rigidity. 
 
                      
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SaybianTv wrote:
Timby have you taken the MD course is Texas, I've watched the  video dvd course over and over, and I just don't think it's enough for me to do them on my own. In places where nobody knows about MD's that pretty much makes the client the on site forman.  I watched a great video on youtube of a lady in Hawaii who built her own, day in and day out. The only thing she imported was some men to do the shockcrete. They went overboard and layed it on inch and a half thick and it collapsed.  What really made her a tough cooky is she kicked them off the job and hand troweled it in the end. That video is what made me know a graphic artist turn gallant maverick buccaneer can do this.



I'm not with the MD folks or do I have any vested interest in the company. I haven't taken the courses and don't have any plans to in the future. My days of doing this type of work are long over. Severe lower back problems (herniated disks). So the labor part of any building system is out. However, I've spent the last 20 or so years researching different building systems. I looked into rammed earth, straw bail, cob, cord-wood, pallet, etc. Al these systems have pluses and minuses.

As for the MD's yes as with most building systems there are parts best left to the professionals. I've spent some time with the earthbag system as well and my comments are the claims aren't always truthful. As with my example URL. They lead you to believe you go out to your construction site and dig up some dirt. Then you put it in the bags. Place the bags on top of each other and then voila you have an earthbag house. Well some of that is true, what is not being said is that you need to have someone learned in the system. Also, the material used to fill the bags needs to be of a certain consistency as well as have a certain amount of moisture. There is no recipe for this mixture. Also, like the test build in Austin, the importance of installing barbed wire was crucial to the build. I'm not saying that in some instances where concrete isn't available that these other systems wouldn't make a better choice. This doesn't mean that MD's aren't superior to the earthbag system.

I'm still skeptical that this systems has the track record of the MD's for efficiency (lower heating and cooling costs) as well as structural strength. There is documented proof that an MD built for a company that used it for storage, survived a massive explosion inside the dome with minimal damage. Also, you can go to the MD site and research MD's that have survived hurricanes, direct hits from tornadoes, as well as forest fires.

Wile most folks wouldn't be able to build an MD from the ground up, this doesn't preclude them reducing the cost of the build by doing things that are within the realm of their experiences. You wouldn't want me to build your stick built house as I'm totally inept when it comes to building things (other than PC's). That doesn't mean you shouldn't have a stick built home constructed because you can't do everything yourself.

MD's have some of the same building practices as other homes with the exception of the shell. You still need electricians, plumbers, HVAC guys, drywallers, etc.

So I'm not touting the MD's as an easy DYI project for the weekend warrior. However, when push comes to shove, which would you rather have a home that is easily heated, cooled, low maintenance, structurally sound or something that easily allows you to construct the home but has dubious claims to structure and energy efficiency? I know that should you decide to build an Earthship or Earthbag home that, at least in our neck of the woods, you are going to have problems with the inside air quality (humidity issues) unless you add another system to the build. This would add more complexity as well as cost to the build. This is already addressed in the MD system.

I hope that I answered your concerns/issues to your satisfaction.

Sorry for getting on my soap box....
 
                      
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magicdave wrote:
The fact about using concrete is this: Concrete is a familiar substance. Its durable nature and versatile applications have made its usage ubiquitous throughout our cities. However this primary building material is also extremely energy intensive to make and transport, and produces a significant amount of the world’s greenhouse gas emissions.



I agree the creation of concrete is energy intensive. However, did you know that the quantity of concrete utilized in an MD (same sq ft as similar built stick home) is almost the same? As for the green house gasses, the jury is still out. While I believe that creation of concrete adds to the generation of green house gasses, I also believe that if man were to curtail producing pollutants that one eruption of a volcano wold do more to pollute (in one day) the atmosphere than all the pollution man would do in a year. Just saying.

It is a better solution to build a timber frame dwelling and fill in the walls with Hempcrete which is just lime and hemp hurds mixed.  It is relative easy to learn and it is far more energy efficient from both the standpoint of the carbon sequestered by growing the hemp and then using the waste from processing the fiber to build a place to live.  That makes it carbon negative.  Using concrete is not the best choice for building.  There are hundreds of examples of hemp/lime construction that the Romans built all over Europe.



I will have to look into this mixture for sure. You may want to look into the following for a green product produce right here in Texas. It utilized a mixture of cellulose, small amounts of concrete (binder) and other low foot print (ecologically speaking) additives. This product touts a very strong as well as high efficiency (high R-value) system for building (http://masongreenstar.com/). Again I don't have a vested interest but it has piqued my interest. This system doesn't have a long track record but it seems meets a lot of the green criteria for building (supposedly). 
 
Dave Bennett
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"Timber" framing can be accomplished using what is essentially OSB made from hemp.  None of it's manufacture uses tress.  Even the glue is made from hemp oil.  I used to like building with concrete and thoroughly investigated using it 20 or more years ago.  I changed my view after discovering the tremendous energy used to manufacture the cement used in concrete.  Even using less of it still burns up lots of energy in the manufacturing process.  I think it is a good that some companies are looking for ways to reduce the quantity of it but there are greener ways of building.  I am doing the lamination myself since buying the 4x8 hemp fiberboard in bulk is the cheapest way for me.  I may have to buy even more clamps though. LOL  I always thought that the old joke about woodworkers never having enough clamp was funny until I started building furniture years ago.  Now I regularly visit the pawn shops and buy every clamp I can get my hands on.
I am building my next dwelling out of hemp board including the framework.  My only wish is that it was legal to grow industrial hemp here.  Using hemp as a building material is carbon negative.

The consensus of opinion regarding atmospheric carbon pollution is not speculation by a vast majority of "scientists."  The very few that dispute the data have "axes to grind."  The acceleration of planetary warming is exponential and will bring climactic devastation worldwide.  Some places will experience unusual heat and much less rain and other areas will be inundated with precipitation.  It is already happening.  I probably won't be around when the hard frost wipes out the Florida agriculture but it will happen.  The Atlantic Thermohaline Circulation (Gulf Stream) is the world's largest heat pump.  It keeps the east coast of the US and all of western Europe warm.  The northern ice mass is melting rapidly and will stop the Gulf Stream.  When it does the east coast and western Europe will discover 6 month long very harsh winter that will reach all the way to Miami.  You might find this site interesting regarding the Texas drought:
http://texasdroughtproject.org/droughtfacts.html ;
 
                      
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Dave Bennett wrote:
"Timber" framing can be accomplished using what is essentially OSB made from hemp.  None of it's manufacture uses tress.  Even the glue is made from hemp oil.  I used to like building with concrete and thoroughly investigated using it 20 or more years ago.  I changed my view after discovering the tremendous energy used to manufacture the cement used in concrete.  Even using less of it still burns up lots of energy in the manufacturing process.  I think it is a good that some companies are looking for ways to reduce the quantity of it but there are greener ways of building.  I am doing the lamination myself since buying the 4x8 hemp fiberboard in bulk is the cheapest way for me.  I may have to buy even more clamps though. LOL  I always thought that the old joke about woodworkers never having enough clamp was funny until I started building furniture years ago.  Now I regularly visit the pawn shops and buy every clamp I can get my hands on.



I like hemp and think it's a great substitution for certain things. I've got some hemp socks and they're the best ever. However, like a lot of these solutions (Hydrogen generation, ethanol, solar, wind, etc) are having trouble getting traction. The reason being it costs more to transport the product (do to lack of infrastructure, etc) and becomes an energy looser. While I think that much of this could be alleviated by making some simple changes, there are forces at work that wouldn't appreciate the move. At least until they can control all the crucial components, thus driving up the costs (greed).

There are many such examples of glue lam already in the housing industry. There is talk of getting glue lam studs. However, in many places wood is still a product with limited life and has some inherent problems. Bugs love wood, whether it's carpenter ants or termites, they can cause a ton of destruction. I don't know about your hemp products. MD's use concrete and mostly steel studs for interior walls.

Don't get me wrong, I really like post-n-beam and log homes. I've seen some really nice SIP homes. I've been playing with the idea of using gabion baskets for the exterior walls. Covering them with a stucco type bonding agent (inside and out). You can't get more earth friendly than rocks. However, one would have to develop a good roof system. So I still have some things to work out.

Not all solutions work for all folks. Texas has a ever changing climate. Extremes are the norm (hot and cold). We have our share of bad weather (tornadoes, hurricanes, large hail, rain storms, etc). Also with the exception of certain parts, humidity rears it's ugly head. I find it alarming that more wind and solar are not being utilized here. I did some research and found the electricity provider I have will not pay me for any overages of electricity I generate. We have an abundance of coal, NG, Sun, and wind but it's not being promoted. I believe that is because of certain groups not being able to control (reap big rewards) these forms of energy.


I am building my next dwelling out of hemp board including the framework.  My only wish is that it was legal to grow industrial hemp here.  Using hemp as a building material is carbon negative.



Agreed. you're preaching to the choir.

The consensus of opinion regarding atmospheric carbon pollution is not speculation by a vast majority of "scientists."  The very few that dispute the data have "axes to grind."  The acceleration of planetary warming is exponential and will bring climactic devastation worldwide.  Some places will experience unusual heat and much less rain and other areas will be inundated with precipitation.  It is already happening.  I probably won't be around when the hard frost wipes out the Florida agriculture but it will happen.  The Atlantic Thermohaline Circulation (Gulf Stream) is the world's largest heat pump.  It keeps the east coast of the US and all of western Europe warm.  The northern ice mass is melting rapidly and will stop the Gulf Stream.  When it does the east coast and western Europe will discover 6 month long very harsh winter that will reach all the way to Miami.  You might find this site interesting regarding the Texas drought:
http://texasdroughtproject.org/droughtfacts.html 



I heard some interesting thoughts concerning the recent climatic changes. Seems there are some scientist that believe that volcanoes as well as the increase in earthquakes may be accelerating the climatic changes. Scientist stated the earth was affected by the big earthquake near Japan. We don't know, as yet, the outcomes from these events. Anyway, I see the perfect storm coming on the horizon. This is just the beginning.
 
Dave Bennett
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Did you see that I am talking about HEMP not glue lam wood?  The stuff is made 100% from Hemp and it costs less than plywood. 
 
Dave Bennett
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Agreed. you're preaching to the choir.

I heard some interesting thoughts concerning the recent climatic changes. Seems there are some scientist that believe that volcanoes as well as the increase in earthquakes may be accelerating the climatic changes. Scientist stated the earth was affected by the big earthquake near Japan. We don't know, as yet, the outcomes from these events. Anyway, I see the perfect storm coming on the horizon. This is just the beginning.


The Glaciers have been receding rapidly for over 30 years.  Recent volcanic activity didn't cause that.  This problem has been accelerating at an alarming rate and using recent geologic events to rationalize what is happening only makes those scientists look like corporate shills.
 
                      
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Dave

I've a ton of questions concerning this Hemp product. Obviously you can grow your own house (legally).

From what I've seen on You Tube and other places is this material is used to fill between structure. So I've the cost of post and beam construction. I don't know about you but in my neck of the woods that's very costly. The wood required for this type of structure isn't green as it's slow growth. Now I mixes this stuff up and either spray or manually put into slip forms. Then I have to trowel it or tamp it. Then I have to cover it with some sort of finish.

This seems very labor intensive. While I really like the hemp product. I don't see it catching on main stream. I'm not sure that it's much better than papercrete. I couldn't find any info pertaining to the strength of the product. It must not be too strong or it could be cast as the structure of the building. Also, how does it hold up to the elements (tornadoes, hurricanes, high winds, etc.)? Also, I would love to know how effective it is preventing heat and cold penetration?

I'm not trying to shoot down your dream or to really put down the product however, it has a long way to go before it can be accepted by mainstream folks.

Please provide some insights .......

Thanks
 
Dave Bennett
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timby wrote:
Dave

I've a ton of questions concerning this Hemp product. Obviously you can grow your own house (legally).

From what I've seen on You Tube and other places is this material is used to fill between structure. So I've the cost of post and beam construction. I don't know about you but in my neck of the woods that's very costly. The wood required for this type of structure isn't green as it's slow growth. Now I mixes this stuff up and either spray or manually put into slip forms. Then I have to trowel it or tamp it. Then I have to cover it with some sort of finish.

This seems very labor intensive. While I really like the hemp product. I don't see it catching on main stream. I'm not sure that it's much better than papercrete. I couldn't find any info pertaining to the strength of the product. It must not be too strong or it could be cast as the structure of the building. Also, how does it hold up to the elements (tornadoes, hurricanes, high winds, etc.)? Also, I would love to know how effective it is preventing heat and cold penetration?

I'm not trying to shoot down your dream or to really put down the product however, it has a long way to go before it can be accepted by mainstream folks.

Please provide some insights .......

Thanks


timby,
It is illegal to grow in the US.  I live in Va.  As far as tornadoes and hurricanes I do not know.  I was just pointing out that it may be possible to use hemp for everything including the "timbers."  The Hemp Hurds will come from Canada.  It all depends what your needs are I guess.  Most dome designs are very wind resistant even when made from "conventional" materials such as wood frame and wood sheathing because of the aerodynamic properties of the shape.  I am always thinking about ways to reduce massive commercial harvesting of old growth forest.  It is "new" here in the states so it may be too soon to know whether it will catch on.  It is catching on in a big way in France and Great Britain.  The biggest problem here in the US is that it is illegal to grow so all hemp related products must be imported from Canada.  It is my understanding that mixing Lime and the waste from hemp processing vitrified the hemp.  There are lots of structures from the days of the Roman Empire that were built with "hempcrete" including some bridges.  Granted they may not be massive structures but there are still viable.  As far as labor intensive is concerned I suppose that is relative.  That would depend upon definitions.  Does it need a protective coating?  Yes what structure doesn't?  Even concrete needs surface protection if you intend to live in it.  I have only ever experimented with it on a very small scale and it does make plant material much like like a light weight piece of stone.  I think based on what I have seen and read that it doesn't come anywhere near the strength of concrete but it does have far superior insulation properties.  I live where it gets pretty cold in the winter, relatively speaking, and very hot and humid in the summer.  If I can keep the interior of my dwelling comfortable without burning much energy I am all for it.  I was just looking at the problems we all face from a different perspective I guess. 
Things that I saw happened regarding over harvesting of trees had a profound effect on me.  When I was a youngster in the 50's my hometown's biggest claim to fame was that it was the biggest supplier of White Ash for Louisville Slugger baseball bats and also for hockey sticks made in the US.  Now there are hardly any large Ash trees left.  The same is true of the hard maple from that area.  Only smaller trees are left.  Because of that I have been looking for alternatives to wood.  So far the two best options I have found is Hemp and Timber Bamboo.  Both are easily renewable and extremely carbon negative.  The giant Moro Bamboo grown commercially in Georgia and Alabama is a viable building material.  If I can develop a building design that works for me that is also an option.  I have access to lots of the smaller Bamboo around here because so many people planted it for a privacy fence and it has taken over their yards.  Rabbits love the leaves and the twig size branches are good to keep their teeth worn down sufficiently.  So I remove it for free but I don't dig up much of the rhizome.

As far as finishing hempcrete is concerned it most often is plastered with hempcrete plaster which is the same stuff only a finer grind.  It could be painted directly I think but am not completely sure about that point.  I make my own paint from milk and I have wondered if the lime in that might help make the surface of the hempcrete harder but haven't experimented with it yet.  My mobile home has wooden siding and a shingle roof.  When I painted it 5 years ago I made the paint for it.  It is weathering very well.  It only cost me about $15 a gallon to make it.  Pretty cheap for paint and because it is primarily milk mixed with lime and a small amount of Borax it may help to harden hempcrete too.

I like domes very much as a building design so if I can incorporate green materials in the design that is what will happen.  I have enough lumber to build the superstructure for a 200sq.ft. dome.  It was all free.  I salvaged it and have been storing it for the last 5 years.  Yes I am a "junk collector" but...... only if it is valuable junk.  I plan to cover it with 1/2" hemp fiberboard.  It is only $15 for 4x8 sheets.  That stuff is entirely made from hemp including the glue.  I hope I covered your questions.  It is incredibly energy efficient from an insulation standpoint,  It cannot be cast.  It must be filled with movable forms just like building a concrete/stone home.  The same technique.  It is not exactly a structural component as in load bearing but...... Building conventionally uses framing, insulation and a covering on both sides.  The biggest difference is the end product.  It is exponentially more energy efficient.  The labor part of that equation is that you can actually do the hempcrete work without having to acquire skill.  It really is a building material that can be utilized by a DIYer and it is carbon negative.
 
Dave Bennett
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timby, I am guessing that you live in the PNW?
 
                      
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Dave Bennett wrote:
I have only ever experimented with it on a very small scale and it does make plant material much like like a light weight piece of stone.  I think based on what I have seen and read that it doesn't come anywhere near the strength of concrete but it does have far superior insulation properties.


Have you done any experiments to compare it against foam or cellulose? The papercrete folks claim almost the same r-value as foam per inch for their product.  I'm having some problems understanding how a product can have thermal mass and a high insulation value at the same time.

I live where it gets pretty cold in the winter, relatively speaking, and very hot and humid in the summer.  If I can keep the interior of my dwelling comfortable without burning much energy I am all for it.  I was just looking at the problems we all face from a different perspective I guess. 



We're on the same page. Texas has a varied range in temps. From blistering hot days to below freezing temps. Sometime even in the same day. Humidity is a serious problem here. Sometime I have to run the AC just to remove the excess humidity.

As far as finishing hempcrete is concerned it most often is plastered with hempcrete plaster which is the same stuff only a finer grind.  It could be painted directly I think but am not completely sure about that point. 



Does this finish coat keep the product from absorbing too much moisture? Here in Texas we have some very serious storms that generate a lot of rain. Also, does this finish coat do anything to add strength to the hempcrete?

I make my own paint from milk and I have wondered if the lime in that might help make the surface of the hempcrete harder but haven't experimented with it yet.  My mobile home has wooden siding and a shingle roof.  When I painted it 5 years ago I made the paint for it.  It is weathering very well.  It only cost me about $15 a gallon to make it.  Pretty cheap for paint and because it is primarily milk mixed with lime and a small amount of Borax it may help to harden hempcrete too.



You may want to patent your milk paint recipe or at least offer it online. Might make a good start up business.

I like domes very much as a building design so if I can incorporate green materials in the design that is what will happen.  I have enough lumber to build the superstructure for a 200sq.ft. dome.  It was all free.  I salvaged it and have been storing it for the last 5 years.    I plan to cover it with 1/2" hemp fiberboard.  It is only $15 for 4x8 sheets.  That stuff is entirely made from hemp including the glue. 



Sounds like a plan. I would be very interested in how it goes. Would be nice to have some pics as well.

It is incredibly energy efficient from an insulation standpoint,  It cannot be cast.  It must be filled with movable forms just like building a concrete/stone home.  The same technique.


Monolithic Domes (MD) utilize a technique called shotcreteing instead of forms. It's used a lot in the swimming pool industry. They spray on 3" of a special mix of crete (over 5000 psi) for the interior. The dome shell is inflated and the foam is sprayed on. Then the shotcrete is applied.

It is not exactly a structural component as in load bearing but...... Building conventionally uses framing, insulation and a covering on both sides.  The biggest difference is the end product.  It is exponentially more energy efficient.  The labor part of that equation is that you can actually do the hempcrete work without having to acquire skill.  It really is a building material that can be utilized by a DIYer and it is carbon negative.



I got that from the vids. My concern was that they used wood in between the product to assist with horizontal integrity of the wall (like brick ties). I understand this ties the wall more securely to the structural elements of the frame. Do you have any ideas/comments concerning how this material would withstand the elements should the home builder not be able to complete all the stages of the ruff in? In other words, if I build a part of a wall and don't get back to it for a week or two. Will the wall collapse, erode, or be otherwise damaged?

Thanks for entertaining my inquiries......
 
Dave Bennett
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timby wrote:
Have you done any experiments to compare it against foam or cellulose? The papercrete folks claim almost the same r-value as foam per inch for their product.  I'm having some problems understanding how a product can have thermal mass and a high insulation value at the same time.

We're on the same page. Texas has a varied range in temps. From blistering hot days to below freezing temps. Sometime even in the same day. Humidity is a serious problem here. Sometime I have to run the AC just to remove the excess humidity.

Does this finish coat keep the product from absorbing too much moisture? Here in Texas we have some very serious storms that generate a lot of rain. Also, does this finish coat do anything to add strength to the hempcrete?

You may want to patent your milk paint recipe or at least offer it online. Might make a good start up business.

Sounds like a plan. I would be very interested in how it goes. Would be nice to have some pics as well.
Monolithic Domes (MD) utilize a technique called shotcreteing instead of forms. It's used a lot in the swimming pool industry. They spray on 3" of a special mix of crete (over 5000 psi) for the interior. The dome shell is inflated and the foam is sprayed on. Then the shotcrete is applied.

I got that from the vids. My concern was that they used wood in between the product to assist with horizontal integrity of the wall (like brick ties). I understand this ties the wall more securely to the structural elements of the frame. Do you have any ideas/comments concerning how this material would withstand the elements should the home builder not be able to complete all the stages of the ruff in? In other words, if I build a part of a wall and don't get back to it for a week or two. Will the wall collapse, erode, or be otherwise damaged?

Thanks for entertaining my inquiries......




Paper is made from trees.  The whole point is to minimize the use of wood.  Is paper crete made with cement?  I am not an engineer but consider 12" thick walls that are mostly plant material mixed with lime.  There is far more plant material than lime.  Foam as in styrofoam insulation?  That is made from petroleum.  I am looking at GREEN building and neither paper (made from trees) nor plastic foam is environmentally friendly.



I would guess that it gets painted.  I do not know since I have never built anything with it.  There is really a ton of information on the net regarding hempcrete though.  That video on youtube showing it being applied like gunite was the first time I have ever seen it sprayed.  I would guess that it does help with strength because both sides of the wall get plastered.  That would act like an I-beam as far as increasing strength.


There are already several milk paint companies in business.  I made my own because most of them sell it in powdered form for about $46/gallon.  I knew I could make it for less.  It is made from "quark."  That's just "cottage cheese" made with vinegar.  Figuring out the proper amount of lime took several tries.  If there is too much lime it foams up like beaten egg whites.  If it is used outdoors it need some Borax in it.  I also found out that it will last 10 years by adding 15% pure tung oil.  Not the crap that they sell at Lowes but the uncut stuff.  Getting it to not foam was the hardest part.  It breathes.  It isn't like latex or oil paint that seal the exterior.  It works by slowly wearing away so it is not a paint it and forget it for 20 years wall covering except indoors.  It is 100% biodegradable. 100lbs. of powdered milk will make 60 gallons of paint.



I am very familiar with monolithic domes.  I was going to build one back in the early 90's.  I changed my mind because of the energy cost to manufacture cement.



I am not sure about how well it bonds to material that is already set.  It isn't anything like concrete in consistency.  It seems to me if you are building a wall you would finish it.  Why would you want to walk away from a sreucture for a long period of time?  I would think that some of the strength of the product is that it all gets done at once so it sets up as all one piece.  You cannot walk away from a monolithic dome with only half of it sprayed.  I did see one video that showed the walls being strengthened with rebar.  If I can find that one I will give you the link.

I will let you know because my very first building is going to be a 12ft. square utility building with a gently sloped roof.

 
                      
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Dave Bennett wrote:
Paper is made from trees.  The whole point is to minimize the use of wood.  Is paper crete made with cement?  I am not an engineer but consider 12" thick walls that are mostly plant material mixed with lime.  There is far more plant material than lime.  Foam as in styrofoam insulation?  That is made from petroleum.  I am looking at GREEN building and neither paper (made from trees) nor plastic foam is environmentally friendly.



I understand the green thing. My intent was to see how hemp ranked against existing insulation's. I know that paper crete is made from paper and a very small amount of mortar however, it's typically made from a process that utilizes existing paper there by being green because it's a recycling process. Just because a product is made from a plant material, doesn't necessitate that it's a good insulator. Cellulose is a good insulator because of the production and installation process. The same way with foam.

I am not sure about how well it bonds to material that is already set.  It isn't anything like concrete in consistency.  It seems to me if you are building a wall you would finish it.  Why would you want to walk away from a structure for a long period of time?



Well if this is DIY and you are the only labor then unless you had time then the house wouldn't necessarily be finished. I just wondered how long it would be unaffected by climate and sun.

I would think that some of the strength of the product is that it all gets done at once so it sets up as all one piece.  You cannot walk away from a monolithic dome with only half of it sprayed. 



Agreed but I wasn't speaking of the dome process but the hemp crete process. The vids didn't say if it was OK to build a wall and later build another. Not all DIYers builders have the time to finish the entire structure before they run out of time. Also, some build the walls and latter dry in the structure by installing a roof system. So the process could take more than several days to build the home to dry in state.

I did see one video that showed the walls being strengthened with re-bar.  If I can find that one I will give you the link.



I would appreciate that. Thanks

I will let you know because my very first building is going to be a 12ft. square utility building with a gently sloped roof.



Looking forward to seeing the process.
 
Dave Bennett
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Here is how hard it is after it is cured.
http://www.youtube.com/watch?v=wRtDh6YUt-0&NR=1

This will answer your question about not doing it all at once.
http://www.youtube.com/watch?v=FcctSvVFheA

http://www.youtube.com/watch?v=b6eMdqJbQI4&NR=1

http://www.youtube.com/watch?v=eZbYsMsMW4Q&feature=related

http://www.youtube.com/watch?v=FV3AqKNR0p4&feature=related
 
                      
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Dave

I'd already watched those vids. They show a group building both homes. That really doesn't show what would happen if I were trying to build one of these hemp homes by my self. It would be a considerable endeavor for a DIYer to build a wall in a single day let alone the entire home. I realize this stuff seems to be stable once a 12 to 24 cure cycle has been allowed.

If you'll note both of these homes had a lot of wood structure. For someone wanting a green home this should be a no no. Another caveat is the roof structure. It's mostly old style. So basically these folks have built a home and then are infilling the walls with Hemp. While this has some green aspects and the material is green many of the building practices aren't. They are little different than the existing wasteful practices already utilize in the house building industry. Let me take this one step further. The amount of concrete used to build both of the example homes utilize nearly the same amount of concrete for the same size MD. So you're not really saving anymore of the ecology by building with hemp. I know, you're going to say that the hemp is CO2 depleting/sequestering. That may be so but they don't say how much CO2 is being sequestered or saved.

So basically the jury is still out concerning this system. I would wager that I'm being just as good (building and MD) on the ecology as anyone building a hemp home that utilizes the existing methods. Of course this would change if much of the structure could be made from hemp instead of wood. I'm not trying to put your system down and I applaud your efforts however, this system has pro's and con's (as does most existing systems). There are no examples provided showing strength, fire proof, earth quake damage resistance, hurricane damage resistance, etc. I can provide these for the MD and many of the other systems already existing. The papercrete system can provide excellent r-value while being virtually fire resistant. While maybe not as green as hemp it has many of the same attributes and maybe more.

The MD outshines them all as by it's very design it's earth footprint is small. Yes concrete is an energy hog but if I'm going to use the same amount to build any other green home we are both starting from the same level. The MD is designed to be energy efficient as well as disaster resistant. It can withstand almost anything thrown at it. By it's very design, being round, it presents a lesser target to any flying debris from a hurricane or tornado. So other than the foam insulation we are pretty much equal for pollution. I'm not seeing the proof of longevity for the hemp product. I'll have to do some more research on that aspect.

Don't get me wrong I think you're on the right track but for me it's not the best solution. I will have to give hemp good marks for the C02 sequestering. I'm still skeptical about the strength and resistive properties of the product. I may be proven wrong in the near future and that's OK too. One thing this style of home would have better acceptance, than a MD,  from any mainstream home buyer as it looks just like other homes.

So keep up the good work and keep me apprised of your progress. I'm always interested in new ways for home construction.
 
master steward
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hugelkultur trees chicken wofati bee woodworking
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Oh my.

I just deleted the last two posts. 

Uh ... if you know I'm gonna deleted stuff, then I think y'all should take this off-line.
 
                      
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paul wheaton wrote:
Oh my.

I just deleted the last two posts. 

Uh ... if you know I'm gonna deleted stuff, then I think y'all should take this off-line.



Not sure how we would know. But no problem. As I stated I was trying to have a debate. Not a finger pointing match.

If this isn't a forum for such debates then you may want to ban me or take me off the forums altogether. Up to you......
 
                          
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One of the things I see is the energy impact to make concrete as Industry scrambles to find a 'greener' concrete

It takes a lot of energy to make it, and the world is using billions of tons of it. Makers are finding better ways to do it.

http://www.csmonitor.com/Innovation/Tech/2008/0312/p14s01-stgn.html

If impact on the environment in total is a concern then earth bag would win hands down.
Saying that even using Concrete if used long enough compared to say wood the total environmental impact
goes down over time.
It probably just comes down to personal choice and funds available as I would be happy to use either system.


We drive our cars on it, we build skyscrapers with it.


But concrete, one of the most common building materials in the world, has an ugly secret: It's a major source of carbon dioxide (CO2) emissions, which contribute to global warming.

Roughly 5 to 10 percent of global CO2 emissions are related to the manufacture and transportation of cement, a major ingredient of concrete.
 
Abe Connally
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Modern concrete has a lifespan of 150 years.  So, you're not gaining much with the lifespan of a concrete house.

5,000 psi concrete is not for a beginner home builder.  Even experts can have issues maintaining 5,000 psi concrete and proper curing.

If you use lime-based plasters on your earthen home, you actually sequester CO2.

Anyone can build an earthen home. The majority of the world is housed in earth, and it remains the longest lived building material. From Mike Oehler's buried designs, to CEBs, to earthbags, there are countless methods to build with earth.  Choose the one that matches your balance of time, money, and energy.
 
                          
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I agree velacrations the only limitations are money and imagination and of course bureaucracy in some
cases.
 
                      
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velacreations wrote:
Modern concrete has a lifespan of 150 years.  So, you're not gaining much with the lifespan of a concrete house.

5,000 psi concrete is not for a beginner home builder.  Even experts can have issues maintaining 5,000 psi concrete and proper curing.

If you use lime-based plasters on your earthen home, you actually sequester CO2.

Anyone can build an earthen home. The majority of the world is housed in earth, and it remains the longest lived building material. From Mike Oehler's buried designs, to CEBs, to earthbags, there are countless methods to build with earth.  Choose the one that matches your balance of time, money, and energy.



Cut me a break only 150 years. Who told you that? The only way that standard mixed concrete fails in that amount of time is if it wasn't prepared properly. The mix used by MD is over 5000 psi and has special ingredients to make the buildings last. Yes if the building were built over a faulty foundation or there are outside forces (truck hitting it, an explosion, etc) the it would shorten the life of the home.

BTW what about stone. There are dwellings in the west and southwest that are centuries old and still standing. Many of these buildings were vacated a long time ago and no maintenance has been performed. It's real green.
 
Dave Bennett
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Where I grew up the stone that is quarried is called bluestone.  It is like a light blue very hard sandstone.  There are houses up there built from it with minimal mortar because it comes out of the ground in layers and all of the pieces are flat and cut dimensionally in standard sizes.  Some of those homes are over 200 years old and have weathered very little with no maintenance except for the roof, windows and doors.  The thermal mass is unreal so they are easy to heat and there is no need for artificial cooling in the summer.  Stone makes outstanding structures.  Earthen homes too.  Outstanding structures.  Bamboo, hemp and dirt and stone.  The energy expended is muscle power.  No fossil fuel required to produce the materials. 
 
                      
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Bluestone makes great walls and walkways as well. Very nice and stable stone.
 
Dave Bennett
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I had a quarry for a summer back in 1970 or so.  Once the block is uncovered on the mountain the rest of it is all done by hand.  Extremely labor intensive. 
 
Abe Connally
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Cut me a break only 150 years. Who told you that?


Concrete industry

The only way that standard mixed concrete fails in that amount of time is if it wasn't prepared properly.


Please note that modern concrete is quite different from anything 100 years old or older.  The truth is, we don't know how long modern concrete will actually last, because most of it is less than 60 years old. Industry specialists predict it can last for 500 years or more under optimum conditions and manufacturing processes.  Those rates are not based on actual experiences, but rather on predictions and estimates.

Many things can cause brittle materials to fail.
 
                      
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velacreations wrote:
Concrete industry


The only comments from the concrete industry state their product will outlast most anything else by over 20 times. They state that as with any product or building system, if not properly maintained or constructed all bets are off. As with all the You Tube vids I've seen concerning earthbags, they must be built correctly or they will fail. The bottom courses have to made with certain materials as to prevent the wicking of water. Also, if the material isn't the right consistency it will cause the building not to be strong or structurally sound.

Please note that modern concrete is quite different from anything 100 years old or older.  The truth is, we don't know how long modern concrete will actually last, because most of it is less than 60 years old. Industry specialists predict it can last for 500 years or more under optimum conditions and manufacturing processes.  Those rates are not based on actual experiences, but rather on predictions and estimates.



As with any building material. The life expectancy is going to be less if not constructed properly or under specified for a certain solution (bad engineering). So many things can make building material fail. If I put in a steel beam and it wasn't engineered to take the weight then it's going to fail. Does that mean the steel isn't a good material to use? Same way with concrete. If you hurry up the mixture or put too much liquid or utilize it where a stronger mix should be used, will cause premature failure.

Many things can cause brittle materials to fail.



Correct...... Many things cause many things to fail. A diamond can be chipped or broken if not properly cared for. Does that mean it's still not the hardest substance known to man? As for earthbags, as I've seen on the sample vides, you are to tamp the bags to make then hard as a rock or concrete. The mixture has water added to aid in this compression. So what we really have is a systems that wants to be just like concrete. The only difference is folks in third world nations don't have the materials to make concrete so they try and mimic it's performance by creating a material that compresses and hopefully in the end acts like it.

So we come back to the beginning. If cost, availability, and the green factor weren't an option. What would you want your home built out of?
 
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Can I call a truce here? This is beginning to sound like a political forum.
 
                      
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Jim Argeropoulos wrote:
Can I call a truce here? This is beginning to sound like a political forum.



You may if you wish. The cases have been stated. In the end if one wants to live in a cardboard box under an expressway that's their prerogative.

BTW politics has nothing to do with this debate.
 
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this is a low cost building system, i lived in this particular one for 4 years warm and dry, the frame is raw trees that bend that diameter and adobe/cob
ef.jpg
[Thumbnail for ef.jpg]
Doom052808-20004-1-.JPG
[Thumbnail for Doom052808-20004-1-.JPG]
 
                      
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pahanna wrote:
this is a low cost building system, i lived in this particular one for 4 years warm and dry, the frame is raw trees that bend that diameter and adobe/cob



What did you use for heat and cooling?
 
Dave Bennett
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pahanna wrote:
this is a low cost building system, i lived in this particular one for 4 years warm and dry, the frame is raw trees that bend that diameter and adobe/cob


Very cool looking place.  I wish I could see more of it.
 
Dave Bennett
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http://www.youtube.com/watch?v=2c3m4b51Lkg&feature=player_embedded#at=61
 
                      
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Dave Bennett wrote:
http://www.youtube.com/watch?v=2c3m4b51Lkg&feature=player_embedded#at=61



So what's your point. We can't make everything out of earthbags, hemp, cob? Also, check your figures on what is expelled into the air for one volcano eruption. I've stated in other forums, if man quit pollution all together for an entire year, that one eruption would create more pollution and would wipe out the gains.
 
pahanna barineau
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here is partial complete framing
Mountain-Gardens-II-239.jpg
[Thumbnail for Mountain-Gardens-II-239.jpg]
 
Dave Bennett
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Beautiful work.  What is the diameter?
 
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