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Thread: Cracks in berms

  1. #1
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    New question here. Cracks in berms

    Greetings, just built my first berm for our backyard pump track and it's looking sweet. However, the dirt has a heavy clay profile, so as it's drying, and I'm tamping and rolling to shape and compact, cracks are starting to appear.

    What's the best approach to take? I'm tempted to just wet it down and fill in the cracks with fine dirt as they appear, and use my tamper and roller as required i.e. wet it down, add some dirt and compact. Repeat until the cracks stop forming.

    The berm is only a week old, it got some decent rain right after it was built and we're heading into winter in Australia, so more rain can be expected. It appears to be settling down nicely and looks like it will be rock hard once dried, but the OCD in me would prefer no cracks.

    Any advice appreciated,
    cheers, si.

  2. #2
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    Clay expands when wet. If it was soggy when you built the berms, it will shrink as it drys out. Solution is to till sand into the soil to reduce the clay concentration. If you pack more clay into the cracks, next rain you'll have to re-shape everything as it needs to expand somewhere.
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  3. #3
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    Lightly watering then sweeping dust into cracks is a pretty regular part of our pump track/jumps maintenance.

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    Quote Originally Posted by cmc4130 View Post
    Lightly watering then sweeping dust into cracks is a pretty regular part of our pump track/jumps maintenance.
    Sweet, 'twas hoping it would be that easy.

    btw cmc, you've been helping me out on that other thread re: pump track plans; I just measured the berm radius ~ way up the riding line, and it came in at a nice consistent 2.10m or 6'12", which hopefully won't be too tight, and at least it's better than what I had originally planned, so thanks again for your input.

    Freaked me out how much dirt got used though, it was ~4-5 tonne for a 180 berm, even with 70 of the berm being cut into the hill face, and a tonne or two of stone wall on the other side to armour and build up.

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