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A Temporary Housing Option — 8 Comments

  1. It would not be difficult for someone to build their own ferrocement posts.

    I would suggest using a length of 4″ PVC drain pipe as an inner form.

    Glue end caps INSIDE both ends of the PVC pipe (see the EMAS videos for ideas how to make your own custom end caps out of another length of the same pipe), and insert a standard tire inflation valve stem in one of the caps. Inflate the pipe to 3 or 4 lbs psi to slightly expand the PVC pipe.

    Then wrap that pipe in chicken wire, or stucco mesh. Apply cement mortar by hand, and then wrap the outside with plastic wrap. (stretch wrap such as is used in wrapping materials on shipping pallets would be ideal, but pretty much any plastic tarp or even garbage bags would work.

    After it has set for a few days, release the air pressure from inside the pipe, causing the pipe to slightly contract. Slide the PVC form pipe out of the ferrocement post and reuse to make the next post.

    Should be able to make a ferrocement post for a few bucks each.

    Keep in mind that if someone wants a stronger post, they can install the hollow ferrocement post by hand, and then fill it with concrete mix later to make a full thickness concrete column.

    A similar technique can be used to make other very useful items. For example, only wrap half the diameter of the pipe with wire mesh, and cover with ferrocement. You now have a custom rain gutter.

    Using shorter pipes, sliced in half lengthwise, and mounted on a board with one end spread slightly to make a half conic section, one can use the half pipe technique to make ferrocement roofing tiles that look a lot like spanish clay tiles, especially if one adds iron oxide to the cement mortar mix to produce a reddish brown cement color.

    The possibilities are endless.

    For lots of inspiration about those possibilities… see http://www.flyingconcrete.com/ (a website often referred to on this blog. Rightfully so.)

    • Those are all super good ideas, Jay. I’ve known about Flying Concrete for a long time, but haven’t heard of these particular building methods. Maybe we should turn the fence post idea into a separate blog post so everyone sees and understands the process better.

      One small variation on the fence post idea. Do as you say but then add a pipe down the center and put cement between it and the fence post. That way you don’t have to fill the whole thing with cement. The amount of cement could be adjusted by the size of the center pipe. Plan ahead so the pipe is easy to pull out. Coat the pipe with oil, have it protrude above the fence post, drill holes for a rope pull and slide it out after the cement has set up.

      • In case you are interested, the TV Show “How It’s Made” showed how commercial manufacturers make concrete lamp posts.
        http://youtu.be/XavLVql5NZQ?t=16m27s

        Clearly my suggested method for thin wall ferrocement poles would not be nearly as strong as those, but they also would be drastically lighter and cheaper.

        Owen, I am uncertain if your oil idea as a release agent will be sufficient. I’m not saying you are wrong, just that I’m unsure.

        Concrete warms as it hydrates in an exothermic reaction, but then cools and contracts as it fully cures. That cooling and contracting will apply some pressure to an inner core form. It is possible that pressure will induce too much friction for the oil to overcome when trying to withdraw a PVC pipe from the center of a hollow ferrocement pole, especially a longer pole that will have a lot more surface area, and hence more friction.

        Then again, you may be correct. I simply don’t know for sure. I recommend experimentation for anyone attempting this method to discover the details of the technique that will make the work go fast, easy, repeatable, and of course successful. The person that figures it out first should post photos or even better, videos of their success for others to admire and duplicate.

        Dang it Owen… now you are trying to piss me off, aren’t you?
        Now my brain can’t stop thinking about whether it is possible to build massive ferrocement tinker toys.
        http://ecx.images-amazon.com/images/I/51DRCT06DJL._SL500_SS500_.jpg

        I’m going to be laying awake at night thinking about what method might be cheap and easy to build big ferrocement hub rings to connect the hollow ferrocement poles together to make giant tinker toys now.

        Sometimes, Owen, you can be a real pain in the neck!!

        (In a good way.)

        • Drats.

          That YouTube link was supposed to start at 16:27 into the video. If you click on it and it starts at the beginning, fast forward to 16:27 to see the lamp posts being commercially made.

          I don’t know why YouTube’s “start at” feature isn’t working today. Sorry bout that.

        • Excellent video on the lamp posts! (It may sound boring, but I assure you it’s not — at least not if you’re interested in how things are made.) Now that is some Might-y-Fine looking concrete. Let’s just hope they don’t test every lamp post like the one at 21:05.

          Hollow posts: I think a lubricated (recycled oil, etc.) PVC pipe will come out if you do it soon enough. Don’t wait any longer than necessary. Experiment a bit to see what works best.

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