weatherproofing / waterproofing mud bricks

Discussion in 'Designing, building, making and powering your life' started by jubuntu, Sep 12, 2007.

  1. jubuntu

    jubuntu Guest

    Im looking at building a couple of raised garden beds out of mudbrick as i have plenty of clay and rather poor soil.

    I figured to do so with mudbricks would be a cheap and entertaining project, however Im concerned that in a bed type situation they would degrade due to the internal moisture of the bed and exposure to the elements.

    has anyone had experience in this before?

    also, if you have a personal recepie for your favorite clay/straw/sand mix it would be appreciated as im a complete novice and have read a few different opinions online as to the mix.

    thanks in advance
     
  2. IntensiveGardener

    IntensiveGardener Junior Member

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    hi jubuntu,
    I'v never done this but its not a bad idea. I'v seen plenty of garden fences made from mud bricks and standing out in the open without washing away etc...
    I beleive the render you put on them is important to stop erosion and water logging of the bricks. When i made mud bricks for a building we used a thin slurry made of cow manure (fresh), bondcrete and mud. Seemed to work wonders for sealing the bricks.
    I'm not sure how the sides of your bricks will hold up on the inside, where they contact with the topsoil, compost, mulch etc...
    It seems as though the more biological activity in the soil, the faster the bricks will deterioriate. Maybe try lining the inside wall of the bed with straw to insulate the bricks from the soil.
    cheers,
    IG
     
  3. jubuntu

    jubuntu Guest

    I read up on some ancient techniques and it noted that mudbricks were laid on a stone foundation to protect from damp, so im guessing it may be an issue for longevity.

    i may look at either painting the inside with a weatherproofing paint, or possibly lining the inside of the walls with plastic.
     
  4. han_ysic

    han_ysic Junior Member

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    render

    Hi Jubuntu,
    I have never done it, but John Champagne did. He got a whole lot of fresh cow manure and mixed it with other stuff (arhh why can't I remember exactly) and used it as render on his house. Supposedly (and it's worked for him) cow manure is water repellant. As a kid you would see years old ones sitting in dry paddocks. They are only broken down by earthworms dung beetles etc. I think you have to get it really fresh and mix it up with water and maybe something else and then spread it. Stinky for a while but then good. I'm not sure about the inside where it touches the dirt, but this works on exposed areas. If you wanted to ask him look up BEND (eco village in Bega, NSW and you should be able to get him.

    Hannah
     
  5. SueinWA

    SueinWA Junior Member

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    In the U.S., mud bricks are called "adobe", which probably has a Spanish base. There are still a lot of them around in the drier parts of the country, but they have built-in problems. The one thing that the buildings DO have to protect them are roofs with wide eaves that limit the amount of moisture that they absorb directly. Even so, they will still absorb moisture from the atmosphere. Your plan of using them for garden beds, which require moisture, would be like building garden beds with sugar cubes.

    Since they aren't fired, they are susceptible to moisture, and will swell and shrink constantly because of their changing water content. The only mortar and the only surfacing that really sticks to them is more of the same: mud, because it has the same properties as the bricks, the shrinking and swelling, thermal expansion and contractions, and eventual breakdown.

    Mud bricks will only temporarily bond with metal, wood, stone, lime or cement mortars, lime plasters, whitewash or stucco because the mud exhibits much greater movement than these other materials, either separating, cracking, or twisting where they interface.

    I'm sorry, but I think your idea would cost you quite a bit of effort with results that will degrade much faster than you would want.

    Sue
     

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