Soil Cement - anyone done this?

Discussion in 'Workshop Tips and Secrets / Tools' started by Daleandee, Jan 6, 2019.

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  1. Jan 6, 2019 #1

    Daleandee

    Daleandee

    Daleandee

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    Being one of those folks that are always looking for good quality at an inexpensive price leads me to ask the group about this method or related info concerning other inexpensive flooring options for a shop, hangar, garage, etc.

    I've done a little research on the topic of "soil cement" and find it interesting as it seems to be a way to get a workable surface with good durability for a lot less cost than calling the guys with the big white truck. Here's one informative source for those interested:

    https://www.thespruce.com/soil-cement-paving-for-driveways-1398082

    A web search will bring up many videos on this subject.

    One friend (with a beautiful Luscombe) used this method for his hangar floor and it seemed to be everything one could ask for at a greatly reduced cost.

    Anyone here have any experience with soil cement or something similar? I'm about to begin the floor in my shop and thought this might be a good option to consider.

    Appreciate any input ...

    Dale
    N319WF
     
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  2. Jan 6, 2019 #2

    Vigilant1

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    Dale, I've read of a similar material being used to make molded bricks for construction in developing countries. Much depended on the type of soil available. Sandy is good, clay and organic matter is bad.
    One of the nice things about a concrete floor is that it gives an opportunity to put down some gravel or chip&dust to get some distance above local grade, then to put a sheet of heavy plastic down on top (for a capillary break and vapor barrier) before the pour. If you are planning to do some in-place mixing right there and just pack and level, you wouldn't get a chance to do this prep. A dry hangar or shop is good for your plane and tools. OTOH, if this is an open-sided structure and you just want a less dirty place to work, then the soil concrete might be a cheap way to go.
    As far as the surface characteristics when using your own dirt, it wouldn't be hard to do a small test area and see how you like the result.
    If the floor was going to be subject to freeze/thaw or frost heave, I'd be reluctant to go this route.
    Have you priced out the delivered ready-mix? Sometimes it is quite a bargain (they get the raw materials for you cheaper than you can buy them, they mix them for you, they deliver them to your house, they pour the resultant mix in your forms--it saves a lot of work). Hire some experienced guys looking for a side-job and you may save some money vs hiring a contractor to do the slab from soup to nuts. If you are willing to do this soil cement and rototill approach, the you won't be afraid of doing the prep work before the pour date (pack the soil, spread the chip&dust, lay the plastic, and lay any wire or rebar on "chairs", then just wait to hear the rumble of the truck.
     
    Last edited: Jan 6, 2019
  3. Jan 6, 2019 #3

    BBerson

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    I did a test strip about 2' x 20' of soil cement in my gravel driveway with the tiller about three years ago. Seems to hold up.
    Was about 1" deep, I think. The tiller could hardly go deeper in the packed gravel driveway.
    I was thinking of doing the basement floor. The roller doesn't interest me. I would mix it wet and screed it like a normal floor poor. Just using the existing sand/gravel.
    The cement ratio can be as much as 20-1 sand/cement ratio. I made a hangar floor with an electric mixer at 14-1 ratio.
    The cement trucks use a "5 bag per yard" ratio, which about 500 pounds of cement and 2000-2500 pounds of sand /gravel, so about 5 to 1 ratio.

    We get moisture that condenses on the surface after a cold spell followed by warm moist air. Plastic underneath doesn't help for that.
     
  4. Jan 6, 2019 #4

    pictsidhe

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    You need to test it with your soil.
     
  5. Jan 6, 2019 #5

    Hot Wings

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    Around here we call it Dirtcrete.

    I did a driveway at one of the rentals this way nearly 7 years ago. It gets rained, on snowed on and driven on wet. It's still essentially hard. It is fray-able - makes dust. but there is no mud to walk through.

    If I had an inexpensive T-hangar on a grass strip, providing the soil is not good farm bottom land, I'd not hesitate to use it. If you plan on using it for a shop, with floor jacks and creepers, you will need the same ratio of Portland to aggregate as normal cement for the top layer. Fly ash, if you can get it, helps too.
     
  6. Jan 6, 2019 #6

    Pops

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    One of the best things I did in building my hanger was using a ditch-witch and digging a 8" wide ditch around the outside of the slab as deep at it would dig ( 42"). Cut thick foam and have the top of the foam at the inside of my form boards. When poring the concrete, pored the slab, piers, and the space inside the trench against the foam in one pore. The ground temp at my location is 53 degs. Hanger well insulated and if its -20 degrees outside the coldest it will get in the hanger with no heat is about +50 degrees. There is also 1800' of hot-water tubing in the floor and a boiler that I have never used. The little 60K btu force air NG furnace does a good job. Easy to heat is the winter and easy to cool with AC in the summer, its 48'x 60'. Also have a wood stove in the seating area and a couch for naps :)
     
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  7. Jan 6, 2019 #7

    BBerson

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    I had two large hangars in Alaska. Cost a bunch to keep warm. Now I mostly design inside the house all winter, so my open shop/shed is unheated. I have an old 37' RV converted to build wings in. It heats up quicker than a slab floor.
    A hangar takes two days to warm up for a 2 hour task, and doesn't match my pace of working only a few hours weekly in the shop.
     
  8. Jan 7, 2019 #8

    Daleandee

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    I appreciate everyone that has commented on this. I have an open front shed/shop that I park my older cars, motorcycle, & lawn care equipment inside of. But sometimes I use the area to do small repairs. I've entertained fully enclosing it but was looking for less expensive options for a possible floor (its dry dirt now).

    As far as bringing the finished slab above the grade ... that won't be too difficult as I either add sand, gravel, or soil before proceeding with the Portland cement. This area never floods (even after the storm of the century two tears ago) so even at the present level I'm not too concerned.

    Currently the estimated cost for a big white truck is about $2500.00 compared to the soil cement at about 10% of that. I have a tiller available and a pretty good helper also. I may give it a go but I have more study to do on this first. I few test pads to see how the soil needs to be mixed is also a wise idea that will cost little to do.

    Dale
    N319WF
     
  9. Jan 28, 2019 #9

    Armilite

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  10. Jan 28, 2019 #10

    BJC

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    The savings would be significant to me. YMMV.


    BJC
     
  11. Jan 28, 2019 #11

    BBerson

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    I am doing my shop floor last week and this week. (1/4 at a time)
    Using a mixer my brother gave me. Five bags of cement was $50.
     
  12. Jan 28, 2019 #12

    Pops

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    Took about 40 yards to do my hanger back in 1998. At todays prices, I would hate to get the bill for the concrete and labor. Also put 1800' of pipe for hot water heat.
     
  13. Jan 29, 2019 #13

    Daleandee

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    Sounds great. Using the Portland cement for a soil cement floor I would need approx 16 bags at a cost of ~ $200. If I use a tiller in my sandy soil (already have one available) and water it in and lightly pack it down as suggested, the cost savings will be significant.

    Dale
    N319WF
     
  14. Jan 29, 2019 #14

    Armilite

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    ============================================

    IF as they say "You will need about three to four pounds of Portland cement for each square foot of your soil cement surface." For a Shop floor it's better to use 4lbs per sqft.

    Just a Slab 20ft x 20ft = 400sqft x 4lbs = 1600/94lb = 17.0 Bags x $12.99 = $220.83. Not counting for any Waste. So a 40ft x 60ft Shop take $$$ times 6.

    Just a Slab 20ft x 20ft = 400sqft x 3lbs = 1200/94lb = 12.7 Bags x $12.99 = $164.97. Not counting for any Waste.

    At Lowes Sakrete Portland 94lb Type-I/II Portland cement $12.99 a Bag.

    If you have the right Sandy Soil and can use it, you save? What is a 1 ton of Sand today, I recently bought a Ton of Peat Gravel for $16 a ton. Sand should be cheaper.

    Of course, your going to Save on Labor if you do it your self. But a Big Job usually means calling on friends to Help, more Cost, Food & Drinks for them.

    You still probably have to Buy Forming Lumber & Stakes.

    You may still have to Rent/Buy some Cement Hand Tools, Mixer, Finishing Power Trowel, Bull Throat Levels, etc.

    So yea, I don't see that Big a Savings, account your also taking Time away from doing other things. A Professional Crew could come in and do the Job in 1-2 days, what might take you 4 weekends to mix and pour a big Slab. You just lost a Month of Time you may have been Working/Using the Shop or doing other things. Now I built my own House and a Seperate 2 Story Garage/Shop when I was 25. Took me a Year start to finish. Dad came down a couple of days and helped hang some plywood on my garage/shop.
     

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  15. Jan 29, 2019 #15

    BBerson

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    image.jpg The space is 14'x28'. I split it into four sections of 7x14' with expansion joints. It is just 1.5 " thick. For airframes, not heavy vehicles.
    At 14-1 mix it takes 5 bags. Digging the floor 6" lower for headroom is harder than the cement mixing. I tried the tiller but it couldn't dig the hard packed gravel so switched to normal mixer, screed method.
    I enjoy the process, reminds of my days working with dad at age 12.
    My wife helps. This is broken up to provide needed exercise while getting visible results.
     
    Last edited: Jan 29, 2019
  16. Jan 30, 2019 #16

    Armilite

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    ==================================================================

    Wow that's thin, 1.5". I don't think I have ever seen less than 4" used. Nice Old Mixer, my buddy had a similar one we used to Pour Footings for his Hugh 14' x 32' Deck. There is probably a lbs per sq in Calc out there. Luckly, most Home Built Airplanes don't weigh much. Do you have your own Airstrip also? I have been looking for an Acreage so I can have a Bigger Shop and a Storage Building/Hanger with my own Grass AirStrip. Just missed a nice flat 10.1 Acre site. Even had a spot for a Shooting Range. Hope it all works out for you.
     
  17. Jan 30, 2019 #17

    BBerson

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    I don't fly enough for a private strip.
    All my aircraft will have folding or removable wings for storage in my yard.
     
  18. Jan 30, 2019 #18

    BJC

    BJC

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    So you have seen it used, at 4 inch thickness. What was the use, and how did it hold up over time?


    BJC
     
  19. Jan 31, 2019 #19

    Armilite

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    ===================================

    No, I have never seen Soil Cement used at all in places I have lived, Iowa, Illinois, Minnesota. Only regular Cement Mix, in 4", 6", 8" Thickness. That Soil Cement Article said minimum 2" and to use either 3lbs or 4Lbs Cement per Square Foot. There is Formula's for Mixing Cement, 3000psi is usually the very lowest they use for Sidewalks, Block Walls, Normal Garage Floors. His application for just a Storage Shed for his Airframe and it sounds like he has a very Solid Base, he could probably use a lower psi. Time will tell if it works or cracks soon. I personally would not use less than 4".

    Here is a good example for mixing Cement for 3000psi, 3500psi, 4000psi, 4500psi.
    https://www.everything-about-concrete.com/concrete-mix-ratios-for-3000-3500-4000-psi-concrete.html

    Slurry Area Calculator
    http://www.angellematerials.com/CustomComponent/CustomComponent3.asp?Tab=1&Post=Y
     
  20. Jan 31, 2019 #20

    RonL

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    I met Mr. Jetter in 1989 when he started this company, it might give you some ideas about the use of compressed soil. Watch the top video about the test block machine.

    In your case you will probably hand tamp the floor but just a little cement added to the dirt will hold it stable very well, just do not expect it to be anywhere close to real concrete. I still have some blocks around the yard in different places that are still looking like worn bricks, they are the size of the ones being put on pallets in the second video. (30years and still good :) )

    https://aectearthblock.com/
     

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