dry stack block vs. poured concrete

Discussion in 'Homesteading Questions' started by Weedologist, Feb 14, 2007.

  1. Weedologist

    Weedologist Member

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    Hello. We are planning to build an earth sheltered house in central New York. It will be built into a south facing hill. We are unsure about what material to use for the walls. We would prefer to use the parged concrete block system because it is easier and cheaper and owner/builder friendly. However, we are concerned that this will not be strong enough to resist the pressures of the earth. The other option is poured concrete walls. We are not comfortable pouring the walls ourselves and fear that it will cost too much to hire out. This will be a mortgage free house and we will be watching very closely where every dollar goes.

    So, the questions are: Will the dry stack block system work? What can be done to this system to make it work? How much does it cost to hire out the poured walls? Can you give any other advice? Thanks and good day.
     
  2. next61

    next61 Well-Known Member

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    I would check wwith a structural enginer. There are so many variables into taking that decision....
     

  3. hunter63

    hunter63 Well-Known Member

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    Need to contact some concrete contractors in you area and have them give you an estimate.
    Also check your codes.
    There are so many variables, given the info supplied, not much of an answer can be supplied.
     
  4. Ramblin Wreck

    Ramblin Wreck Well-Known Member Supporter

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    If I were building an earth sheltered house, I would go with poured walls erected by a reputable contractor. The dirt is going to want to move and you need something substantial to hold it back. Best wishes in whatever you choose to do.
     
  5. hunter63

    hunter63 Well-Known Member

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  6. SolarGary

    SolarGary Well-Known Member

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    Hi,

    There have been a lot of successful earth sheltered homes built with dry stack block.

    There is a lot of material on this here:
    http://www.builditsolar.com/Projects/SolarHomes/constructionps.htm#Stack

    The book by Rob Roy is quite good. I went to one of his workshops, and he really knows his stuff. He likes the dry stack for owner built earth sheltered homes, and the book has a lot of how-to on this. I am guessing he would answer specific email questions.

    Gary
     
  7. Jim S.

    Jim S. Well-Known Member

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    I have a friend who did dry stack for a basement, but then he got cold feet and poured concrete down through the holes.

    Personally, I don't get it. I have laid block walls using masonry cement, it is not that hard to do and all you need is the materials, a string, a level, trowels, a wheelbarrow, gloves and your finger (to run along the seams). I know for a FACT that conventional concrete block walls will stand up as a basement or building walls. It is not rocket science to do it, you can find plenty of DIY Web sites to tell you tips.

    So I just don't get the appeal of the whole dry stack deal at all, when it is so easy to do it the proven way, and with 2 people you can really stack a wall quick. :shrug:
     
  8. gccrook

    gccrook Well-Known Member

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  9. heather

    heather Well-Known Member

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  10. Jim S.

    Jim S. Well-Known Member

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    gccrook, that's what my buddy said too, but he said he did get the cold feet when he started thinking about that thin layor on the outside and all that dirt pressing in on it. LOL. So he had the wall pumped full. Which, if you search it, makes it as strong as a poured wall.

    Hey, I'm not saying it wouldn't have worked over the long haul as the basement to his raw log home. It could have worked. But maybe it wouldn't, too.

    Call me a conservative, but I'll stick with what I know works, and let you folks do the new stuff. In 80 years, we'll know the real answer. Cuz I can show you 100-plus year old basements laid conventionally that are fine.
     
  11. highlands

    highlands Walter Jeffries Staff Member Supporter

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    We are building a tiny cottage that will eventually be bermed on the windward side (northwest). It is concrete and stone. We poured the slab on foam board and poured two half walls. The rest we did with dry stacking and then pouring the cores. I mortared the first course of block to the slab. Very easy and fast. I also did one section of interior partition wall as mortared masonry partition block. Slower but I could not use steel there as it will be the stand for my salt water aquarium - salt and steel do not play together well. You can see pictures and discussion at:

    http://sugarmtnfarm.com/blog/2006_11_01_sugarmtnfarm_archive.html
    http://sugarmtnfarm.com/blog/2006_12_01_sugarmtnfarm_archive.html
    http://sugarmtnfarm.com/blog/2007_01_01_sugarmtnfarm_archive.html

    If I had to do it again, which I do, then I would use dry stacking and core pouring again.

    One little detail that my blog does not discuss, yet, is that we will have a hollow space around the house between the house and the hill. This is our water shield wall. Outside of that there will be PAHS type lappings of plastic and insulation.

    Cheers

    -Walter
    Sugar Mountain Farm
    in the mountains of Vermont
    http://SugarMtnFarm.com/blog/
    http://NoNAIS.org
     
  12. gccrook

    gccrook Well-Known Member

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    Yeah. I did a dry stacked block walk in closet that doubles as a storm shelter for us. I poured concrete in every cavity, and then poured a concrete ceiling. I was wanting to make sure that it would withstand a tornado. I really like it, but I did it myself, and it is small, so pouring concrete in those cavities wsn't too bad. If I was doing a whole house, I would do it much like Tio Ed on the link above did, where there are concrete "columns" every 4 feet, and a bond beam. This is a very good system, and easier to do.
     
  13. Weedologist

    Weedologist Member

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    Hello and thanks for all the replies. Would it be too redundant to fill every single one of the cores of the blocks with rebar and concrete or would filling cores every few feet or so work? I have no problem filling every core, just wondering if it is essential. I am willing to use pilasters wherever necessary. How many and how far apart is suggested? Thanks again.
     
  14. highlands

    highlands Walter Jeffries Staff Member Supporter

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    I filled every core because I wanted maximum thermal mass inside the insulated envelope to stabilize our house temperature. We have 84,000 lbs of mass right now and are adding more as we do interior partitions within the 252 sq-ft tiny cottage. I only did rebar in about every fourth core. We used PVA fibers in the concrete. I did a channel beam at the wainscot below the windows and at the top of the wall to lock everything tight.

    Cheers

    -Walter
    Sugar Mountain Farm
    in the mountains of Vermont
    http://SugarMtnFarm.com/blog/
    http://NoNAIS.org
     
  15. agmantoo

    agmantoo agmantoo Supporter

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    In another life I had a dry stacked hog facility. The sows could not tear the partitions apart and they were dry stacked. I would not have a concern but I would use the recommend amount of fiberglass reinforced product. I know where there is a roof made from dry stack product and block. The roof is nothing more than a wall laying horizontal. The roof was set in place with a crane after the material was applied to both sides and cured.
     
  16. gccrook

    gccrook Well-Known Member

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    You would't need to fill every core, except for thermal mass. If you fill about every 4 feet with concrete and then a bond beam all around the top, you have essentially built a concrete post and beam filled with concrete blocks. Then the layer of bonding cement on the outside and inside, and you're good to go. Some of this depends on the soil structure surrounding this earth sheltered house. Different soils act differently in terms of pressure applied on the structure.
     
  17. Hoop

    Hoop Well-Known Member

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    I built a surface bonded block basement for my log home. Poured columns every 6 feet.
    The only thing I didn't like about it was the sizes. You need to prepare for this.

    My building came in at 41' 4" x 28' 2" on a building that ideally would have been 42 x 28.

    I used 10" block.


    Would I do it again? Yes. The surface bonded block wall is more waterproof and supposedly stronger than a block wall.
    In our location with a strong building code, no further waterproofing is needed when one uses 1/4" of surface bonding.
     
  18. MyHomesteadName

    MyHomesteadName Well-Known Member

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  19. OntarioMan

    OntarioMan Rockin In The Free World

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    Although surfaced bonded block is stronger than block and morter - it is not stronger than properly poured/designed concrete.

    Any wall built into the side of a hill is a "retaining wall" - and for that you're going to need an engineer. Free standing walls, basement walls, retaining walls - can all be worlds apart depending on the exact situation.
     
  20. Steve L.

    Steve L. Well-Known Member

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    Weedologist, I'm in Central NY, too, and very interested in this subject. I could be available to help/learn when you get to the work part. PM me, please.