Visit the forum instructions to learn how to post to the forum, enable email notifications, subscribe to a category to receive emails when there are new discussions (like a mailing list), bookmark discussions and to see other tips to get the most out of our forum!
Hab lab design review and discussion
  • Vote Up0Vote Down September 2011
    Please review the design my mother and I have worked up for the hablab.  You'll get the best view by loading up this sketchup model:

    Don't forget to play with the layers to see all the information I've put into this model.

    And you'll see a slightly older version in this youtube:

    And you can see the information we've collected so far and organized up onto the wiki here:

    The parameters that led to its design as it is shown is externally accessed rooms, internally accessed rooms, 6-10 sleeping rooms, a kitchen, a bathroom, and an area to get together in the middle.  We also have a directive to do it using CEB floors where possible.  I think this is particularly risky, but as an experimental structure, oh well.

    We'd like your feedback regarding its design, particularly with a view towards simplicity of construction.

    One other thing - this building is being constructed in a location with no building codes - no quantity of advice regarding what will or won't pass code is going to be directly applicable to this experiment.  If you want to point out something for code related reasons, please limit it to constructively informing us how to calculate, design, and modify it so that it will fulfill the code you are thinking of.
  • 52 Comments sorted by
  • Vote Up0Vote Down
    September 2011
    My biggest concern has to do with the locally made "straw bales"...

    I'd asked on the blog, if Marcin knew the difference between hay bales & straw bales, and his reply was that FeF had plenty of weeds, or rather "insulation"... (Which means he either didn't understand the difference, the question, or didn't care?).

    The biggest difference (& what looks to be a problem from far away), is that hay is still including all of the plant leaves, flowers, & seeds, whereas straw is the leftover stalks after the plant matter that could be used as animal feed has been removed.

    Marcin keeps alluding to or implying in his videos that the fields of weeds in the background are what is to be turned into these 'straw bales'.

    Even if you have no grain crops on FeF, baling up raw weeds is potentially baling up a food source for some vermin you didn't wish to be attracting or feeding during the winter ;)  Then there is that whole drying process that seems to be in danger of being skipped, like the plants should have been already mowed and drying in the fields by now if they were to be used for staw bales by November?  They'll dry much slower after they've been baled up...

    I have never tried to personally bale hay or straw, but from what I've read of straw bale construction, the longevity of the straw bale infill is only going to be assured if the straw bale was dried to below about 13% moisture before going into the wall.  I've done lots of reading on the pros & cons of straw bale construction, as I was considering it for my retirement home, and have also read through several research papers on testing the load limits and moisture handling of such.

    Hay will probably be a poor substitute, even if it was from weeds, and especially if it isn't dried out first, as it will decay and decompose in the wall, and thus degrade any insulative value it might have had.  In addition, if it was sealed into your CEB sandwich while still wet enough to decompose, it might pose a future structural failure problem, as the bricks on the bottom would be subjected to enough moisture to return them to mud if they weren't stabilized (and fully cured first)
  • Vote Up0Vote Down September 2011
    We need about 1500 bales.

    This straw is within range, about 200 miles away at 3.25 a bale.  That is a cost of over $5000 for the straw, $5000 that we simply don't have at this stage in the game - not to mention a tank of diesel for each truckload at that distance.

    Given the need to compromise on what we can afford, perhaps we can find a different way of ensuring our insulation is stable - such as installing screened vents so that the bales and walls can breath enough to dry out, even if they aren't openly exposed to the air.

    Do you have any suggestions that would enable us to address your concerns without spending five grand?

  • I'm not a hay/straw expert, but my concern with wilder weeds would be possible toxic plants might get baled up alongside okay ones, like Ragwort whose pollen can cause respiratory and other problems in people and deadly toxic to horses and other farm animals, which was how I heard about it -- when I was a kid, our neighbors lost a horse and two cows to it, and I remember my dad having me help him go through overgrown areas in our 3-acre plots and very carefully removing the plants, root and all, for destruction.  We had to bag their flower end in plastic to avoid exposure to their toxic pollen and handle them carefully with gloves.

    "All natural" sounds great, but some natural plants (or in the case of ragwort, invasive introduced species) are potentially deadly poisons and should be looked out for before they might get baled up with harmless ones.
  • Vote Up0Vote Down
    September 2011
    i wonder if you could make the void air tight and have a vaccuum? how hard would it be to seal the walls to that degree? wouldnt have to fill it with anything.

    seems like you could have some sort of sealant on the walls. not sure what you could do cap them.
  • Vote Up0Vote Down
    September 2011
    Vacuum in walls would = collapsing walls...  Air pressure is a powerful thing, see tornadoes...

    I wasn't suggesting you *had* to go out and buy straw, only that from the video implications, Marcin kept implying that FeF was preparing to bale up green weeds, which means that the time is really short.

    If those weeds are to be used for staw bales, every bit of them needs to be mowed ASAP, and allowed to start drying long before any baling is attempted, because they will dry much faster in the fields spread out (even if it rains, though still much slower if the weather is wet.)

    Howard brings up valuable points, is anyone there at FeF able to identify the plants that are targeted?

    This is another case where Marcin held enough cards close to his chest that no one on the outside had any idea that he wasn't talking about real straw bales until it was probably too late for anything else to be done, & probably because he didn't think it important enough to share, even though it would seem that he's not an expert in this field (either).  It may be hindsight, but it might have been possible to raise the cash to get real straw, or (gasp!) actually plan far enough ahead to have grown a usable grain crop, and harvest wheat or something from it (for sale to offset the costs?), and enjoy the free straw left over...

  • Vote Up0Vote Down
    September 2011
    how bout this one... we bow the walls out and as the vacuum increases we add weight to the top to increase the outward force?
  • Vote Up0Vote Down
    September 2011
    It would probably be cheaper to just get commercially available straw, wouldn't it?  Considering the costs of sealing the walls, and then pumping them down...  Not to mention the structural engineering that probably would need to be done to find out how much vacuum could be applied without causing structural weakening, etc.
  • Vote Up0Vote Down
    September 2011
    are the internal workings of straw like little vacuum tubes? i dont understand where it gets its insulating powers. what if we grew some bamboo and sealed one end and then vacuumed sealed the other end. and had a bunch of them piled up between the walls?
  • Vote Up0Vote Down September 2011
    The Vacuum is not a viable idea - The forces involved are incredible.

    Vacuum doesn't conduct heat because there is no media to conduct it with.

    Non-vacuum insulation is formed by the alternating layers of air current stopping material with spaces of air.  The simplest form of this is like a triple paned window - two different air gaps, which slows the transition of material heat from one side to the other.  

    A bale of straw has thousands of these (as does fiberglass batting)  A bale of straw also has a higher thermal mass, which amplifies the effect because the air gaps make it so that the straw doesn't connect solidly with other straw in a consistent way - so you have to try and conduct it through the straw, which is not a good conductor, and through the air between the straw, which is a worse conductor.  Then the thermal mass effect slows the movement of the heat - one calorie of heat in a fiberglass batting will change its temperature more than one calorie of heat in a hay bale.  There's just more STUFF to heat up.

    so combine the moderate thermal mass of the bale with the fairly low conductivity of the bale, and you get an effective insulator.

    The bamboo would leak air without energetic treatment, and since the heat mostly goes around and through the bamboo instead of through the middle of them, it'd be just as effective to simply stack bamboo in there as to stack evacuated bamboo..
  • The initial testing of the beams for the buildings did not go well.

    I set up for the test by bridging the beam across supports 21 feet apart, as they will be in the long span of the building.

    I placed a tape measure beneath, locked to show how far the board was deflecting.

    I then attached a simple bracket on top with screws to keep the rebar from falling off

    I then attached braces on one end - 2 2x4's each to keep the board from rolling over easily.

    Me and my assistants then began loading 20' #4 rebar (13.36 pounds each) along the top of the beam, simulating a spread and fairly uniform load.

    We had just loaded 100 rebars onto it - showing a fairly obvious deflection of about inches (2%) when we experienced a torsion failure.  The bracing I had installed failed and the beam tipped over, dumping the rebar onto the ground.

    This test was worse than it would be on the building for several reasons.

    - The load was *only* on the one span - the overhangs to either side were not loaded at all.  In a real load situation, the overhang would counterbalance some of the load.
    - The bracing was weak - the building bolts these beams down to the building, resisting torsion.  Also, the load is a square-pressure (tends to keep it flat)

    I consider this test to be a failure for the hab lab because of the alarming deflection - 5 inches - over the span, with only 1300 pounds placed upon it.

    The weight of the straw bales is expected to be at least 8.3 pounds per square foot, and the roof that is expected to be supported by this beam is approximately 16*21, or 336 square feet.  With 1 PSF of steel and 0.65 PSF wood frame by two, our roof system weighs *static*, about 10 PSF.  a 20 pound live load on top of that (snow) would bring us to 30 PSF, or 10,080 pounds.

    that is 7.7 times the load I put on the beam and had it deflect 5" over a 240" span.

    so what to do about this?  I'm thinking of some possibilities...

    - support the beam with the walls inside the building, move the walls a foot or two to allow this.
    - use a flying arch in the main open to provide support for the roof (buttress the columns it sits on with extra thick walls) 
    - use 2x10's x 6 or more wide, glued and screwed together to make four masssive beams, capable of supporting a small country, or, a roof made of straw bales
    - get an engineered truss from the local engineered truss supplier - if they make them that strong.

    Please, give me some help here guys.  What do YOU think the solution should be to support the span?

  • I hope to not bury that very serious question, of course, but something that's been egging my layperson mind on the design is heat distribution.  Yes, CEBs hold heat, I understand the concept, like stones in a fire will still be warm quite a long time after the fire has burned out ... but that also means that CEBs that are cold, I imagine, will take awhile to heat up.  The hab lab seems to have a number of rooms on the periphery that are completely walled off from the other interior rooms, and only have access to the outside.  Is the only means of heat getting into those rooms radiant heat from the walls?  Is the only source of heat the fireplace with the chimney?

    Maybe its just because I have no working knowledge of thermodynamics, but it seems like the only room that would be really warm would be the room encompassing the fireplace.  Is there a plan for heat distribution ... heating/cooling vents or somesuch?

    I wonder if it might be possible to use some sort of water heating/cooling, could even be pipes beneath the CEBs in the floor, that would circulate through the fireplace maybe using metal coils.  This could also be used to heat water for hot showers, washing dishes, etc.  I once lived in a place with no electricity for over a month, so no electric waterheater, just cold water ... but we achieved hot showers by plugging a hose into a copper tube that we coiled through the fireplace and attached another hose on the other end of the tube and ran it to the shower ... it was quite hot.

    I'm not sure how much power would be required to circulate heat in such a fashion, but maybe a heat engine of some sort, perhaps on the top of the chimney to take advantage of the chimney versus outside air temperature difference, making the fireplace even more useful as a power source in addition to heat.
  • What ever you do, you should get good quality straw bales for the walls. I hope that there could be some farmers that would love to donate or assist with this effort.

    Now for heating and temperature control of the building , has anyone considered earth tubes? If you can run some earth tubes into the building. see

  • What about incorporating prefab strawbale walls. An interested technique was developed in Ontario Canada. See what was done at Fleming college  See
  • Vote Up0Vote Down
    October 2011
    >  What ever you do, you should get good quality straw bales for the walls.

    My understanding is that FeF will bale weeds cut on the property and compress them into bales.  People have expressed concern about this in other forum entries - especially if the cut plants are not given enough time to dry completely.

    - Mark

  • Heat distribution through Passive Annual Heat Storage - We're hoping to pass the insulation/mass index required to make the regulation of the interior of the building pretty much a non-issue - the winter cold won't penetrate and the summer heat won't penetrate.  The interior should be a comfortable temperature all the time anyway.  if its not, perhaps we can add more insulation to the floor - or more thermal mass in general.

    As for the outer-accessed rooms - they *are* not directly heated, and furthermore, that is by design and request.  they're three season rooms, not four season rooms.  They're sleep rooms, not work rooms, and should not be considered to have comfort heating even required for livability.  Or in other words, pull on a blanket, ya wimp. ;)

    I appreciate the dire warnings about weed bales, *and* these concerns are understood *and* these concerns have been communicated *and* I am advocating for them.  Unfortunately, the sources I have located are NOT interested in giving them away and they require $3.15 a bale, we need 1500 bales, which is about $1500 in transport and $4725 in bales.  Unless concerned parties want to provide upwards of $6500 earmarked for straw bales specifically (we're talking 2+ big rig truckloads here), it appears that we're going to risk using the weeds in exchange for six and a half grand we can spend on other things we consider more valuable than avoiding the risk of weed bales.  On the upside, its neither rained for weeks nor is it expected to in the near future, so we will be able to bale today and put them under protection so that they do not get damaged from subsequent rainstorms.

    Prefab strawbale walls.  OMG NO.  all that lumber to hold it together and cementous plaster and... no.  This doesn't fit at all.  We want to use compressed earth blocks, not 2x4's and denim.  Building with bales is *trivial* - why would we find it necessary to purchase (or build) prefabricated panels?  Prefabricated panels are a 'factory' type idea - make them automatically/cheaply at a factory site, ship them for quick-and-easy installation on the building site.  We're building on site, so this kind of production idea doesn't really fit.

  • Earthtubes is an interesting idea, as a way to get combustion air to the heater... but... I'm not sure how we would be using the 'preheating' part of it.  We're not using forced air anyway.

    Perhaps I'm not grokking it entirely but its essentially a preheater for the intake air in the building?  At the expense of a considerable amount of PVC pipe?

  • Proposal for supporting the roof sturdily without the need for the beam-spans.  Compressed Earth Blocks.

    Need to complete a Funicular study of the archwork curve, of course, but this is the concept.  There are butresses west (left) of the columns to the left of center.  For details see the model


  • As an example for earthtubes, lets take the average underground air temperature of 58 degrees in Kansas. Using a four inch diameter 100 foot run of earth tube can supply a room with air preheated to 58 degrees, this would reduce active heating requirements and supply needed fresh air to a super-insulated building.
  • Hello David,

    don't You think its easier to increase the beam size for the roof? If You want, I can do some static calculations for the beams if I get all relevant data.

    Using arches, three points have to9 be considered:
    1) Arches cause significant horizontal forces for adjacent pillars or walls
    2) There is high pressure on the bricks in an arch so You should know the maximum pressure Your CEBs can stand
    3) How constant is the quality of the CEBs You produce now? One weak brick in an arch that collapses through massive force, will cause a catastrophic failure of the whole structure. In a brick wall thats not the problem because loads are taken by neighboring bricks if one would collapse


  • @mmardik Which is relevant if you need to suck in air to blow around the inside of your building.  But we're not sucking in air to blow around the building.  The only visualized air intake (at this point at least) is the air intake for the combustion - which isn't harmed by being cold at all.  On the other hand, if the building IS at a lower than 58 temperature (brr?)  that can help.  The quesiton is are we going to get that kind of thermal benefit just from being in contact with the ground, obviating the value of using an active transfer fluid?   Also, I worry about the cleanability (and the requirements TO clean) the earthtubes.  How is this addressed?  I wouldn't want some mold to be growing in there... do I have to blow a string through the entire system, then drag a rope then drag a wipe through them?  How often?

    @bastelMike No, not really.  I don't think it will be easier to increase the beam size of the roof that much.  We're talking about the requirement to support 30 PSF load over 336 square feet (21 foot span) on a single beam - that is over ten thousand pounds on each of four beams.  Thats a static load of 10PSF and a dynamic of an additional 20PSF.   I think it will be easier and cheaper to engineer and build an arch than it is to justify the expense of five ton beams.

    1) Yes.  A calculable force that can be compensated for, and of necessity, must be.  I am aware of the forces in an arch.  You might notice the buttresses and walls in the model and consider they *might* have been placed with that in mind?  ;)

    2) Yes, actually what we want is a minimum - so we can make a safety margin.  My initial calculations indicate that we have a 18 fold safety margin on the expected strength of the bricks.  We'll have to do some testing on actual bricks to validate the expected strength against the actual.  We may be able to adapt our 150 ton punch to measure the compression strength of the brick.  The new mexico building code requires a compressive strength on a cured brick of 300psi.  ( If we can pull 300 out of a fresh brick, I'll be entirely happy.)

    3) Yes.  Our current brick quality is not obvious, as we don't have any measurement of it.  Quality control is a concern, particularly when using them in situations like this.  Medium term, I want to equip the CEB machine with quality measuring capability - A measure of the compressive force achieved during stroke, and consistency of output dimensions.  I would want to touch each brick used in a high stress situation such as the voussoirs with a schmidt hammer or similar hardness tester to validate it is entirely adequate for the purpose.

  • End walls.

    this is my initial design for CEB end wall on the main central area.  I think it has a weak spot between the corner of the door and the chlerestory.


    I could take that weight off by using the arch embedded int he wall, making the door with infill.  If we build the arches we already have invested in building the falsework - why not use it a couple more times?


    What do you think?
  • For more information I refer you to the following link:

    and I quote from this page "(...One pipe is generally
    considered to carry enough air for one room.
      In theory, you could have as many earthtubes as you wish, but the
    slower the draw-time, the warmer the air moving through it (or cooler in
    the summer).

    Cleaning earth tubes is
    an easy matter - simply lay nylon cord in the pipes while constructing
    and use it to pull a bleach, peroxide, alcohol or disinfecting solution
    soaked towel through the tubes.
      Tie a second cord to the towel so that you leave a cord in the pipes
    after the towel has been pulled through.
      We suggest installing a standard furnace filter at the earthtubing
    inlet grate to prevent dust and insects from entering the pipes.
      Keep in mind that mold only grows on surfaces with fuel to support it -
    clean pipes will not support mold growths.
      Many people worry about keeping the earth tubes clean, but you rarely
    see folks cleaning their home heating and cooling ducts.
      Earth tubes are nothing more that air intake pipes - and round pipes
    are much, much easier to clean than rectangular duct work.
      Earthtubing is a very simple and cost-effective means to temper air
    intake for any home.
      They are especially important for high thermal mass homes, which can
    be very aggressively vented, ensuring quality indoor air (versus
    air-tight conventional construction...)"
  • Hello David,

    in case You are still interested in a beam construction, I did a structural analysis for You. Acccordingly 12cm x 30 cm (4.8"x12") beams should carry the load, with a deflection below 6cm (2.4"). And the beams won't weigh 5 tons, just 300lbs each ;-)

    Hopefully someone on this forum will do a second calculation to check for errors!


    Beam OSE HabLab roof.pdf 23K
  • An advocate of using earthtube will collaborate with me and help by 

    - a proposal for how the building would be modified to utilize the pipe (like, where would they go, how would the air be motivated to go through them)
    - a proposed trenching plan for the pipe according to that modification
    - how much earth would be displaced by the trenching
    - how many linear feat the trench will consist of
    - how much pipe would be needed
    - how many fittings/elbows would be needed
    - a quote for how much all that pvc would cost
    - an estimate of how much time and expense it will take to dig all the trenches, place the pipe, and backfill

    Why would I need all that?  That is what I would have to do even decide if it is capable of being incorporated into this project.  Honestly, I'm busy and not entirely convinced its worth my effort - but I'm not going to stop you from trying, or discredit the information without a full analysis.  (a full analysis that I'm reluctant to commit the time to)  Are you worried that your effort in that regard would go useless, unused?  Probably a fair concern - after all, if it costs thousands of dollars and 100 man hours to install it, its almost impossible to justify the expense at this time.  But if you think its a good idea, you can make a proposal - and maybe if we don't use it in THIS building, we'll use it in another!  We're going to build others, after all, its open source information!

  • Bastel

    thank you, do you have the math you can show you work on that so we can double check your math as you mention?  You can put it here or on a wiki page.

    These people sell beams that exceed those dimensions a bit, so they'll be a tad stronger.  If we used two 16' for each section (joined or supported in the middle somehow I suppose) we would use 16 of them @ $143.52 for a cost of 2296.22 plus shipping - which their site utterly fails to accurately calculate, and suggests that $11 is what should be expected for UPS ground.  :?  

    Can you research up a source?  Ideally we'd use 32' long beams for this purpose, which length will likely be a premium.  Its not clear to me how the roof would adequately be supported or structural integrity maintained without another pillar/wall support and the 16' beams.

    And all this beaminess needs to balance against the fact that a reusable form for arch centering is relatively cheap (though I don't have an accurate estimate on that yet, its just 2x4's and 1x's or plywood, I'd give myself $250 to do it with) and CEBs are pennies each (cost of fuel).  Whats the cost benefit ratio there?


    This pdf seems to have information for engineering glue-laminated beams that might be a cheaper way to make big beams.
  • At the meeting last night we discussed the viability of using the glulam beams.  The problems we considered and found mostly insurmountable on our limited budget of both money and time are several.

    - the time it takes to create the glulam beams ourselves from stock
    - the cost it takes to order them from a factory and have them shipped to the site
    - the likely need for a crane to lift them into place

    We can sidestep the need to buy/create/erect these large motholithic beams entirely by simply placing the roof on top of the walls.  It was decided that it would be more pragmatic to go with what we have, the CEBs.

  • Are the ferro-cement channels not used for the roof David?
  • They are not, DreamBuilder.  The roof is made of modular wooden boxes that are supported on a grid frame.   The ferrocement channel technique appears to be more complex and time consuming than we care to attempt.
  • Brilliant David. This covered with marine plywood sheets and ferrocement topping gives a strong, light weight roof that returns clean water for drinking to the water tanks. The pre painted metal roofing fades with time ; the paint 'chalks' and the toxins are in the drinking water.
  • That is an interesting idea, Dreambuilder.  

    I worry about using structured lumber products in the construction - no OSB, no Plywood, stick to stuff we can make ourselves - dimensioned lumber and CEB.

    A ferrocement roof using marine plywood would be startlingly expensive - we're talking 2.50 a square foot for *just the deck*.  The metal roof is only $1 a square foot.

    can you explain what you mean by a 'ferrocement topping' - how thick? Constructed of how much steel in what form?  Its pretty important when it comes to engineering my structure to understand how much the roof weighs.

  • The less I say about this  in my current emotional state, the better.

  • Who's running quality control on this during the build? Doesn't look like a ton has been done though so it shouldn't be too big of a deal to tear down and start over with the lessons learned to everyone helping on the build.
  • Time is running out and given the magnitude of this building I think you should forget the CEBs and just order cinder blocks, even if it means using all of the money meant for the "christmas gift". Safety is #1 priority.

    What you showed in those photos may be okay for a small residential bungalow but definitely not for an industrial manufacturing building.
  • What is in those photos isn't okay for a small residential bungalow, much less a 10 person habitation building, particularly that in this case, that is the base of a retaining wall that is supposed to support an additional 8 feet more of bricks on top of it.  That is just plain unsafe.

    And nobody, apparently, thinks quality control is important.  There wasn't a ton done last night as you see - but I bet today they've put in another 24-36 man hours on it, and I *suspect* it has continued in the same vein. 

    I informed that section of wall had to come down and be rebuilt properly.  Marcin said that it would not be coming down.  I told him I wouldn't have my name on such a building and left.

  • Is there anything going between every couple of courses to keep the wall from cracking?

    Maybe every 4 courses put a thick layer of high strength concrete with rebar embedded in it. That might help to compensate for the lack of overlapping and other issues.

    On the other hand, I don't know if the same methods apply to CEBs that do to brick or cinder blocks. Overlapping is important in regular masonry construction but these CEBs are just dirt, does it really matter? Seems like overtime it'll move and settle and compress together anyways.

    How strong are these CEBs? If you take a pressure washer and point it at the brick does it disintegrate into a dirty puddle?

    Another option is that after the wall is done you could apply a really thick layer of cement plaster on both sides to hold it all together.
  • There is nothing going between every couple of courses to keep the wall from cracking.

    Concrete is expensive, and takes time.  They don't consider that they have time.

    It applies all the more to CEBs because they don't have the same tensile surface properties that fired bricks do.  The reduction means that they need MORE overlap to get the same effect.  they do form cracks., and they don't settle like that.

    We haven't done that kind of experiment with a pressure washer, but, more or less, yes.  It would take a good amount of chewing for the pressure washer to make it disintegrate, but it would be able to dig into the surface fairly expeditiously.

    The cement plaster would just crack and break off, concrete and blocks have different rates of expansion.  Also, plaster is not structural and should not be used as such.

  • Something like this could be rolled out between courses to keep things together (might have to cut it in half):


    Or whatever they can find at the local home improvement store that's cheap and looks like it'll hold together.

    The same kind of mesh like material could be used for the cement plaster. Basically the same cement plastering technique that they use when dry stacking cinder block walls, where the plaster is what actually holds it all together.

  • Vote Up0Vote Down
    October 2011
    Looks like the wheels are coming off the build project. I am a bit mystified why they did not go with the already proven Brazilian model with 10% stabilized block and interlocking Lego bricks? The Brazilian model uses glue to keep the block together, has 1200-1400 PSI strength and the work is already done with the engineering and testing...

    I noticed in the video lots of oak trees on the propery. Why were they not cut with a chainsaw, trimmed up and used as beams? Alternately use recycled steel I beams?
  • Demystification: Because we don't have that kind of brick, that kind of source material, or that kind of press.  Yes, it has been proven that that if you put massive embodied energy into a building, you can make a strong building.  That's hardly the point, Metz.  We KNOW we can build a sound building out of concrete.  If we only go with 'the already proven and more expensive' models, we aren't learning anything!

    There are lots of walnut and oak trees, yes, but the custodian of the premises is not interested in chopping them up for structural bits.  Also, they won't be seasoned - effectively putting green wood as spanning timber in a building is not a recipe for happy results, its going to get all bowed as it dries out.

    Recycled steel I-Beams are quite expensive too, we do have a budget that is well below conventional construction.

    Essentially, gratuitous use of manufactured high embodied energy materials is what we're trying to *avoid* in the construction of this building.

    Concrete block is made of concrete.  Concrete plaster is made of concrete.  They stick together and they don't expand at different rates because of this.  Putting cement plaster on earth blocks will not be an equivalent action to cement plastering cement blocks.

  • Vote Up0Vote Down
    October 2011
    @DavidIAm - I have been reading your messages since you decided to "bull doze" your way into FeF.  On one hand I can admire your spirit, but on the other I think you are being foolish.  After everything you've been exposed to via Marcin's attitudes, I am truly astonished that you defend anything that's going on there.

    You are an intelligent man with a lot to offer the Open Source Movement, why are you wasting your time?  You can talk all you want about budgets and low cost goals but you know darn well it's just bad planning and a narrow minded focus that caused all this.  Marcin is a loonie, lets face it.  He is going to harm many more people than he ever helps.

    I like you, please get out of there before someone's blood is on your hands.

  • Vote Up0Vote Down
    October 2011
    But 1000 blocks only uses around 6 bags cement powder. Recycled steel I beams where I'm at are about 50 cents a pound when I do the conversion. Since scrap goes by the world market rate, it should be close to the same price there. Stabilized CEB interlocking blocks can be assembled with glue or dry stacked. 2500 block = aprox 1000 square feet.

    If you went with a i beam frame then you can dry stack the CEB. Even a log pole barn structure...

    Regarding the use of green logs, didn't the early settlers use green logs for building log homes? In my brief career of whitewashing barns throughout the Midwest I seen quite a few barns with logs as structural beams and often still having the bark attached. You already was working on a sawmill, would that have been a excellent way to saw some beams earlier this summer?

    But anyways, you already did your thing. My shop is going up with recycled steel and eventually stabilized interlocking CEB.

    Since it is stabilized I can tile it, stucco it, or leave it plain.

    As far as the wiki, there are really no workable plans I can use to build anything yet. I contributed a oven design but since I d t have wiki access, I emailed. Never heard a word back.
  • Vote Up0Vote Down
    October 2011
    i think you can get a wiki account with that open id thing. i think it works with alot of email accounts.

    i know yur not really interested in the ceb press but in defense of the wiki ill note that the creation flame guys in austin built one. theyve mentioned the wiki was difficult  and lacking but they got it done, without any direct help from fef.

  • Vote Up0Vote Down
    October 2011
    Im going with a manual one for now.  $200 for raw material versus thousands for the present design,
  • I agree Dawg.  I'm out.  They refuse to build the building right, I walked off site and am only going back to get some of my and my mother's equipment that is there.

    Green logs - you don't build a log house with horizontal green spanning timbers from my study - you stack the timbers up to make the walls, they're not spanning anything.  The only spanning bits are the roof beams which are at a steep angle (much steeper than our roof generally) so that the forces are at a different angle, and the bowing doesn't have much end effect.

    production rates on manual presses are much slower - but the ose liberator produces bricks so fast its difficult to keep up with and outputs an inconsistent brick size. 

  • Vote Up0Vote Down
    November 2011
    do you think it would be a good sop to use the earth pulverizers for a day and make a pile of dirt by the press and then the next day just scoop up the dirt tahts ready?
  • Vote Up0Vote Down November 2011
    If you are able to make adequately pulverised earth, the thoughtful preparation of proper input materials will make a big difference.  Stockpile material until you have enough for your production run, then lickety-split create your bricks.
  • @dorkmo:

    Forecasting the effect or relative productivity, I think, is a futile thought exercise.  Set it up that way, try it out, record the results, compare to other methods.  That's the best suggestion I can think of.
  • @Howard-V-Agnew : about CEB thermal mass properties regarding heating and cooling. For the last 15 years every structure i have been involved with : in slab hydronic heating pipes have been placed. Heated with timber or chip boiler / furnace in winter and solar HW in summer. The main calorifier HW tank / heat storage tank size is 1000 li to 5000 li or even bigger in the systems I put together. This large heat storage supplies Domestic HW via a pick up coil (clean cold water is heated so no 'bugs' breeding below 54 Deg. Cel.; as in electric domestic HW tank that stratifies the cooler and hot water) and the floor heating. Both circuits and temp. regulated with a thermostatic mixing value: the floor may never be warmer than 27 deg. Cel. because foot sweat gland problems, the domestic HW tap is set at 54 deg. Cel. according to scalding regulations.
    CEB structures outer wall could be double skin with gap insulated. Inner heat sink looses nothing to outer skin. Passive solar gain to floor heat sink via windows or doors. Or outer skin of straw 'cakes' (compressed bail breaks up into strips) or polystyrene (as done since 1960's) and rendered.

    @DavidIAm : You need a small team supporting your vital position. FeF is the most amazing concept. GIFTED / Philanthropic money flows in!!!!  Failure could damage gifting money. I DEMAND quality for my support.  A structure needs to be done right once. In say 25 years to come the next team cannot redo a structure (wastes resources like $ and time). Structures are there to ADD property VALUE not to detract from it down the line. 
    Redoing Lifetrac parts is part of the design process and DIY repair for owners later. But the shop/shed/structure/hablab should have permanency from the start.

    Regarding the ferrocement topping for the roof over the waterproofed ply sheets; 25 mm should suffice. 
    I costs make you use of the pre painted metal roofing then 'pre flush' units and a small reed bed will filter out chalking paint from the drinking water held in tanks.
    David you leaving would be a great loss. Marcin is please to slow down a bit to make to end out come the show piece it can be. "Rome was not build in a day"

  • Vote Up0Vote Down
    November 2011
    David has been relieved of his position at FeF and is no longer working there.  See Marcin's recent blog posts about the status of the HabLab and bringing in an expert to look it over.

    - Mark


Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Login with Facebook Sign In with Google Sign In with OpenID Sign In with Twitter

In this Discussion