I came across the wiki article at some point never made it that far down, but we figured that much out just by putting our heads together before pounding a single tire.
I guess NM an Spain are 2 known Isolated locations where the conditions are just right and they got lucky.
Its advantageous to tap into the earths stable temperature but dumping heat into it wont help my cause. Which brings me to one of my initial questions, on a true Earthship design the low winter sun bearly reaches the bottom of the back wall, the floor is the only one that gets heated, part of the reason I drawn my sketch with a 24 degree roof line so that the sun can hit the entire back wall also, I am starting to thing a by the book Earthship wont do well at all in Michigan winters. Even Michael Reynolds in an interview mentioned that in colder climates the insulation wrap needs to extend below the floor too.
The wiki article goes on to mention Malcolm Wells, an architect and authority on earth-sheltered design, recommends an imperial R-value 10 insulation between deep soils and heated spaces. Wells's insulation recommendations increase as the depth of the soil decreases, I got to look into this, not very familiar.
I guess a better aproach would be to figure out a raport at which depth and how much insulation should be installed under the floor, in such a manner that given enough time and no aditional input the floor would stabilise closer to earths temperature rather than outside, while at the same time when heat is aplied be it by sun or fosil, it will only penetrate down to the insulation releasing it back at night into the room rather than keep sinking.
I too don't fancy much rules of thumb, throwing a couple layers 4 feet below the floor level may do the trick if I get lucky, I'm not that lucky.
this would be an interesting equasion to solve there are so many variables, and this is all experimental, I would not even know where to begin, I'll start by looking at Malcolm wells work maybe he can save me the trouble I am sure he is more qualified than me to make a proper recomandation.

Thanks for pointing out the wiki can't believe I missed it.

http://www.sbse.org/resources/docs/wells_checklist_explanation.pdf
this Malcolm Wells guy has a very interesting view to share, I'm soaking it all in, aparently he advocated underground living, I have yet to see an example because he also advocates sunlight wonder what his version looks like

http://www.sbse.org/resources/docs/wells_checklist_explanation.pdf
this Malcolm Wells guy has a very interesting view to share, I'm soaking it all in, aparently he advocated underground living, I have yet to see an example because he also advocates sunlight wonder what his version looks like http://www.malcolmwells.com/resources.html holly molly tons of resources, just hit the mother load, it's always best to have a few different views and lots of works to learn from

Here's something you might try; find another operating earthship in Michigan, (and by that, I mean one in which someone has lived for at least a couple years) and see if you can get an invitation to visit. People usually like to talk about their projects.

While you are there, you can take notes on what the occupants say works and what doesn't. In my opinion, that would be more valuable than any amount of Internet research.

I have considered that, as I mentioned there is a similar house built not far from my lots, it was done in the 80's, a lady clerk at the city hall told me about it, I looked up the owner and left hil a mesage.
I think I found a decent source of information, underslab insulation is a must, it is common for in floor heating, be it solar or artificial, found somebad examples of non insulated heated slabs.
http://inspectapedia.com/Energy/Slab_Insulation.php

ok so I have done some reading watched some videos, I'm more visual, about basements and slabs, radiant heat, watterproofing, insulating, and I came up with a new scheme for the floor, the jury is still out weather how much thermal mass I should have/how far down the insulation should be, and how thick, I learned that styrofoam is rated about R 5-6, the yellow marker shows it about 6 inches, that should be R 30 almoast overkill, the walls add up to R70 earth has 0.8 and 18 inches worth. have a look let me know what your thoughts may be

Posted By georgec on 24 Jan 2014 06:17 AM
...I learned that styrofoam is rated about R 5-6, the yellow marker shows it about 6 inches, that should be R 30 almoast overkill, the walls add up to R70 earth has 0.8 and 18 inches worth. have a look let me know what your thoughts may be...

What do you mean by "the walls add up to R70 earth has 0.8 and 18 inches worth"?  Is that some kind of new math?  According to my math, 18 inches x R0.8/inch = R14.4.

Styrofoam (with a capital "S") is a trade name applied to Extruded Polystyrene (XPS), while sytrofoam (little "s") is a common name often used to refer to Expanded Polystyrene (EPS).  EPS is generally white and consists of tiny beads stuck together, i.e. styrofoam cups or trays.  XPS is often colored pink or blue.  Dow blueboard is one common form.

EPS can be obtained in several densities generally ranging from 1# per cubic foot (Type I, typically what is available at big box stores and lumberyards) up to 2.5# per cubic foot (specialized construction material).  Nominal 2# density EPS known as Type IX is available from foam suppliers and has a compressive strength similar to XPS foam.  EPS has a nominal R value of 4.0 per inch @ 75F with the higher density material having slightly higher R value.  Another point worth noting is that the R value of EPS goes UP as the temperature goes down.

Here is a chart of EPS typical properties: http://benchmarkfoam.com/eps-properties/

XPS is similar in density and strength to Type IX EPS and has a typical R value of 5.0 per inch, but this gradually degrades over time due to off-gassing.

EPS generally costs less than XPS and gives you more R/$ value. 

I purchased Type IX EPS foam treated with borates (for bugs and termites) for under my slab for $0.35 per inch per square foot while the cost of XPS was approximately $0.50.

thanks for taking the time and write up this Styrofoam (with a capital "S") review, I just recently started looking into it and I am soaking in all that I can, I came across most this info allready and the math I used is rather simmilar to yours.
yes I figured about 14.4 for the rammed earth, there is a process a builder from british columbia labeled it Syrewall ( might have misspelled that too ) it's rammed earth with a layer of insulation built in, in my drawing I show it in yellow aprox 6 inches thick we'll call it foam for now, the type will determine later based on what is available, I figured an R value of 5/inch, we'll go with 4, so that adds another R24, also I read in some articles about basements insulation that an outside laye2 is commonly applied along with vapor locks, I added that in my drawing as well, if we figure in that one too that is another R24, ( I was figuring 30 prior )
in the end if this will be the final sheme we have 14.4+24+24=62.4 that was the math for the entire wall assy, if a better foam is used such as XPS as you pinted the number goes up, that is all great in theory but that is a lot of foam I'm sure it will add up $$$$, I have a few ways arround that but at the moment I am only discussing the principle, my concern at this time is weather I thought this through or not, weather that slab is a proper design, weather the vapor block is in the proper place , the drain tiles and all, I tryed to borow that based on what they do with basements. the slab insulation again 6 inches worth about R24, borrowed this from what I saw done with radiant heat slabs same idea just powered by sun rays instead, the whole south wall is supposed to be all glass, my concern is that sufficient? I am showing it in the drawing about 2 feet below the floor level that should be enough thermal mass to catch the sun may be too much, I'm a newbie.

off I go to read you post again and the link you posted, as for the choice of insulation, I have an Idea, not sure if I am doing the right thing here but I can get large amounts of EPS at no cost, might actually get paid to haul it away, I know this might sound Hippy - ish, part of the reason Michael Reynolds tires did not become popular, but here goes nothing:

in the food industry there are lots of packaging used made out of styrofoam, not talking about cups, one of the ones I had in mind to use as a building block, there are those fancy table grapes we handle lots of them in the fall they come in Styrofoam boxes, they are roughly 18X12X6?, the walls are about one inch thick, after they reach destination they go to the land fill, I could make bricks out of these fill them inside with more Styrofoam cut from other boxes, it souds cheap and I am sure some would frawn uppon this aproach but they are free and lots of them at any fruit market when those grapes are in season, so why not. There are also a lot of meats packaged this way, but those are tricky all bloody and such.

I am concerned about burying them so I have to read up a bit on the topic, read something about some comercial products having a foil on both sides, that remains to be determined, but its a thought, also one of my customers is a foam factory, we bring them this stuff in barels, it's a 2 part I am told, I could mix it an pour it on site I am told you can make lots of it out of 2 55gallon drums, and the chemichals are not that espensive, the finish product is.

again thiese are details, there is always the home depot way, at the moment I am most concerned if that floor will be watter proof and the heat won't leak down into the ground, most concrete slabs are 8 inches and they do a layer of foam, I believe, for radiant heat, not sure if 2 feet of dirt is too much or not enough for passive solar thermal mass, not sure if R24 underneath it is good enough to prevent the heat harvested in the day to leak into the ground.

George

took a better picture during daylight "Another point worth noting is that the R value of EPS goes UP as the temperature goes down."

actually this works for me most of this insulation is in place to keep the house warm in the winter, so if it performs better in colder weather I'm all for it, personally the summer heat does not bother me much and realisticaly no one should need AC beyond july and aug in michigan thou most may start it in april and not shut it till november

If you are trying to get by on the cheap, you could get a dump truck load or two of coarse sand and fill your free foam boxes with the sand and stack them about 4 layers deep under your slab filling any voids between the boxes with loose sand. Dry sand has an R value of ~0.5 per inch. If you had 24 inches of fill consisting of 4 layers of sand filled foam boxes that's ~4" foam @ R4/in plus ~20" of sand @ R0.5/in, that comes out to ~R26. Realistically, 2 or 3 layers of foam boxes filled with sand would probably be sufficient. Put down a good quality sub-slab vapor barrier prior to placing your sand filled insulation boxes to insure the sand stays dry. Wet sand is a poor insulator.  Prior to covering the sand with your floor material, rent a vibrating plate and go over the sand base to ensure it is fully compacted.

acctually the method is not the concern, I can rig up a hot wire and fill the boxes with cut styrofoam out of other boxes, you'd have to see them pretty fancy interlockable and such, drywall tape could seal them and you got a styrofoam brick, I'll see about getting a few and take a pic. they are kindof molded, if I had to guess i'd say it's eps rather than xps just because they are white.
my concern was styrofoam is styrofoam? regardless if it's grape boxes or homedepo stuff? could there be a variation? is there something I am not forseeing? I know this stuff is an enviroemental issue and it never breaks dowm, that could work for this project, I also read that if it gets wet it looses value, I could seal them in cheap trashbags, I drew a vapor block below them with a layer of sand below it and 2 feet of gravel below it, would that be sufficient? that was more the kind of info I was looking for, does that drawing look like enough precautions to keep the whole project dry? any better ideeas?

The EPS foam sold at stores and used for home wall insulation is treated with a fire retardant and has a certified/tested smoke rating. The styrofoam cups you get with your coffee are not treated and have no application for home insulation use. I would check with your building code if what you are trying to accomplish is allowed/legal. Every county has a building code and while they may be lax, they still have codes.

The EPS rated foam also usually has a borate treatment to ward off insects from boring and destroying your foam. Carpenter ants, termites, and other insects or rodents can and will destroy EPS if not treated, especially in a below grade application.

Some of these "alternative" building methods like using old tires has been shown to cause more damage to the environment and a safety issue to the home occupants than originally believed. Tires release a lot of carcinogenic chemicals into the ground and they off-gas. Also, a tire fire will burn for months or even years. It's next to impossible to extinguish.

I don't think there is any point in trying to reinvent the wheel. Use methods that have been tested and time proven. It will save you time and money. Most importantly, you will end up with a system that works, not an experimental system that might prove to be problematic.

I will agree to a point, thanks for the reply by the way as far as the type of foam you pretty much settled it, those were concerns I had as far as reusing a product that was otherwise intended. as for the disagreeing part, you'll never have progress without experimentation, I try to keep a balance between proven and new ideas, in other words take the foam boxes for example of course I am going to consider it especialy since they are free of charge plentifull and I may be able to use them at the same time I will compare them to a product that is proven and atempt to meet the same specs, if treating it with pesticides and such prooves to be too much trouble than fine they can go to the land fill that is somebodyelses bad choice of material and I can not save the world., I would not throw them in without a second thought either. it's odd howdepending who you ask you may get totaly different answears, an enviroementalist will tell you styrofoam never breaks down a builder will tell you if not treated the bugs will eat it and it will soak up with water and R value will dive. The tires, I gave up on that ideea mostly because building that way took too much realestate having a 32 ft mound against the house, since I have gotten all sorts of bad mouth about off gassing and such, but mostly what I concluded so far tires beeing a bad idea is the entire concept that method was developed so that anybody with a sledge can build a wall out of nothing, without a foundation beeing needed right on the dirt, while that has it's purpose given my location I need a bit more involved design, as previously discussed, to insulat under the slab or not? forgot what the numbers were but I believe we get about 4 times more rain than Taos NM, my lots thou not in a flood zone are virgin forest as far as I could dig with a shovel the dirt was high quality top soil the darkest I have ever seen, perfect for gardening not so much to set a house right on top, once it gets involved where equipment needs to be brought in, might as well figure out a different scheme maybe one that is proven, I am trying to use alternative materials but for the most part so far my drawings are inspired by what I read recarding more standard/ proven methods.

Posted By arkie6 on 24 Jan 2014 02:10 PM

Posted By georgec on 24 Jan 2014 06:17 AM
...I learned that styrofoam is rated about R 5-6, the yellow marker shows it about 6 inches, that should be R 30 almoast overkill, the walls add up to R70 earth has 0.8 and 18 inches worth. have a look let me know what your thoughts may be...

What do you mean by "the walls add up to R70 earth has 0.8 and 18 inches worth"?  Is that some kind of new math?  According to my math, 18 inches x R0.8/inch = R14.4.

Styrofoam (with a capital "S") is a trade name applied to Extruded Polystyrene (XPS), while sytrofoam (little "s") is a common name often used to refer to Expanded Polystyrene (EPS).  EPS is generally white and consists of tiny beads stuck together, i.e. styrofoam cups or trays.  XPS is often colored pink or blue.  Dow blueboard is one common form.

EPS can be obtained in several densities generally ranging from 1# per cubic foot (Type I, typically what is available at big box stores and lumberyards) up to 2.5# per cubic foot (specialized construction material).  Nominal 2# density EPS known as Type IX is available from foam suppliers and has a compressive strength similar to XPS foam.  EPS has a nominal R value of 4.0 per inch @ 75F with the higher density material having slightly higher R value.  Another point worth noting is that the R value of EPS goes UP as the temperature goes down.

Here is a chart of EPS typical properties: http://benchmarkfoam.com/eps-properties/

XPS is similar in density and strength to Type IX EPS and has a typical R value of 5.0 per inch, but this gradually degrades over time due to off-gassing.

EPS generally costs less than XPS and gives you more R/$ value. 

I purchased Type IX EPS foam treated with borates (for bugs and termites) for under my slab for $0.35 per inch per square foot while the cost of XPS was approximately $0.50.

For your application what was the thought process, was it a radiant heat slab ? Can you elaborate? I am assuming you are talking of a standard 8" concrete slab, insulation directly below it, how much did you use (inches) how did it do, should have gotten more? Feedbac helps

Posted By georgec on 25 Jan 2014 11:22 AM

For your application what was the thought process, was it a radiant heat slab ? Can you elaborate? I am assuming you are talking of a standard 8" concrete slab, insulation directly below it, how much did you use (inches) how did it do, should have gotten more? Feedbac helps

My application is a south facing walkout basement slab in Arkansas.  The walls are ICF.  Deep ground temperature here is around 60F-62F.  Few if any builders put any insulation at all under slabs down here.  I just put 1" of Type IX EPS to give me ~R4.5 thermal break under the slab.  No radiant heat.  If I were farther north, I would have installed at least 2" or 3" of this material under the slab.  This was installed over a 10 mil vapor barrier that was installed over ~8" depth of 3/4" clean drainage gravel.  My slab is steel reinforced 4" thick concrete which is pretty standard for a residential slab.  I also had poly fiber mesh added to the concrete mix at the batch plant.  I don't know where you got the idea that you need an 8" slab for residential use. 

maybe 8" was for the wall, I guess I am trying to get an acurate Ideea of common practices first, I am trying to use alternative materials, so I need to figure out a way where pound for pound if you will results will be similar, also considering location, 60f ground temps sound great, I may not even bother you deffinately have much milder winters,

My ideea is very simmilar walk out basement, no house on top thou, I am looking into ways of making a rammed earth floor for the properties it offers, granted the finish level may be a light weitht cement of some sort but for the sake of conversation we'll leave that out for now.

so for 49F ground temps and much less sunshine 6 inches of insulation under the slab is probably just right, give or take some, I had 6 mil on my drawing 10 it is than, we do get plenty of precipitation depending on what is available I may beef that up too, I had roughly 2 feet of gravel in my drawing , I can't say it would hurt it much, reason for that was to bring it down to the footing level, frost line here is 42 " average I went for 48 to play it safe, in a old book I read maximim frost penetration was 56" for this area, guess it warmed up a bit since the 70s.

the slab depth I was planning about 2 feet, to take as much advantage of the south windows, not sure if I am overdoing it but from a structural point of view, Ramed earth is good for 600 psi concrete for 2400 I think, considering the deep freeze and frost heves ( I think thats what they call them, compresion against the building and foundation due to surrounding ground freezing ), might be just on target with that too.

did you do any foundation drain system, I added it to my drawing just to be safe, can't hurt it I guess.

George

Posted By georgec on 25 Jan 2014 02:57 PM
maybe 8" was for the wall, I guess I am trying to get an acurate Ideea of common practices first, I am trying to use alternative materials, so I need to figure out a way where pound for pound if you will results will be similar, also considering location, 60f ground temps sound great, I may not even bother you deffinately have much milder winters,

My ideea is very simmilar walk out basement, no house on top thou, I am looking into ways of making a rammed earth floor for the properties it offers, granted the finish level may be a light weitht cement of some sort but for the sake of conversation we'll leave that out for now.

so for 49F ground temps and much less sunshine 6 inches of insulation under the slab is probably just right, give or take some, I had 6 mil on my drawing 10 it is than, we do get plenty of precipitation depending on what is available I may beef that up too, I had roughly 2 feet of gravel in my drawing , I can't say it would hurt it much, reason for that was to bring it down to the footing level, frost line here is 42 " average I went for 48 to play it safe, in a old book I read maximim frost penetration was 56" for this area, guess it warmed up a bit since the 70s.

the slab depth I was planning about 2 feet, to take as much advantage of the south windows, not sure if I am overdoing it but from a structural point of view, Ramed earth is good for 600 psi concrete for 2400 I think, considering the deep freeze and frost heves ( I think thats what they call them, compresion against the building and foundation due to surrounding ground freezing ), might be just on target with that too.

did you do any foundation drain system, I added it to my drawing just to be safe, can't hurt it I guess.

George

here's another one for you, how deep were your footings if any, should the gravel be installed right above the footings as I dew it, or maybe below, I ballparked the sizes ar thia moment the gravel begins just above the footings, I show roughly 16 inches worth, couple inches of sand to protect the vapor block, than the vapor block about 6 inches of insulation , and 2 feet of rammed earth, I believe I got the order of it right just looking for some input as far as how deep in raport to the footings should the gravel begin, and maybe 8 inches worth is sufficient maybe I should do more insulation and thermal mass instead considering what I am trying to accomplish. I really can't see too much thermal mass for a floor beeing an issue in this design since it will be insulated from the deep soils. any input much apreciated George

Posted By georgec on 25 Jan 2014 02:57 PM
 
...did you do any foundation drain system, I added it to my drawing just to be safe, can't hurt it I guess.

Yes, I did 4" perforated PVC around the inside of the footings and around the outside of the footings except for the walkout side which slopes downhill.  My interior 4" drain system goes through a penetration in my footing and drains down the hill.  My interior 4" drain pipe also has a vent that rises through my slab and then turns and goes out through the wall ~2' above the footing.

Posted By georgec on 25 Jan 2014 06:15 PM

here's another one for you, how deep were your footings if any, should the gravel be installed right above the footings as I dew it, or maybe below, ...

On the walkout side of my basement, my footings are only ~12" deep because that is all that is needed down here.  I installed 3/4" clean gravel flush with the top of my footings on the inside.  Then I covered that with 10 mil vapor barrier, then 1" EPS foam up to the forms where my walls would start.  This 1" EPS foam covers the inside ~6" of my footings so the slab rests on top of the foam rather than directly on top of the concrete footings.  My footings set on undisturbed earth.  Actually, because of a lot of rains that we had prior to pouring my footings and the clay we have down here, I rented a jumping jack and tamped inside my footing forms prior to pouring the concrete.  Also, I used fastfoot fabric for my footings.

Here are my footings:  http://www.fab-form.com/fastfoot/fa...nSmith.php

I came across the fast foot on a video by chance, I also saw some other way of pouring directly into the ditch, pretty fancy iron suports, pre leveled to rest 2x4s on and drag the footing surface level, thought it was a cool idea, so from your description you layed the gravel flush with the top of the footing, my drawing doesn't show the gravel till above the footings, I asume you know your stuff so that will need to be adressed. in Michigan to the best of my knowledge the foundation must rest below the frost line which is 42". I drew mine at 4 ft why not, now i'm not sure but if I were to do a standard concrete slab, I asume they would require the footings to be 42", now I am trying to do something different, more like a half basement setup, and than fill the entire 4 ft with gravel sand and insulation and dirt up to grade level, final proportions still to be determined. I am impressed with your choice to run drain tile on both sides of the footing especially since you are on a grade and it has a run off, and I thought I may not need it but threw one intere any way, you definatelly got me thinking. obviously my floor needs some touching up, I will definatelly keep all this in mind when I redoit. althou I have been adviced against this I am seriously considering those EPS ( I think that is what they are ) table grapes boxes, for insulation, for what I am trying to acomplish I could use a lot of it, I honestly don't even want to try and add up what the high end stuff will cost, I am surprised that bugs and such would munch on the stuff, I thought styrogoam takes some 3000 years or something to break down, I am thinking using even thicker plastic and be generous with it, maybe spray some pesticide arround the perimeter, come to think of it not sure what they do at the vineyards but they throw some sort of a bomb in the trailer and close the doors, by the time it gets to the Detroit market from California any critters that got mixed up in the grapes are dead, all these trailers have a poison sticker on the back door, come to think of it in some sense that styrofoam has been treated in the end we can all dream and draw, and debate different qualities of different materials, but in reality we have to be realistic and if it comes between spending a small fortune to bury lots of insulation in dirt for an experimental design, not doing enough because I could not afford it, or doing a foot thick EPS that cost me the fuel to haul it home, grape boxes it is least that is what I am thinking at the moment