retainging wall question

Discussion in 'Landscape Architecture and Design' started by jdwilliams1, Nov 24, 2001.

  1. jdwilliams1

    jdwilliams1 LawnSite Member
    Messages: 97

    I have read every post on retaining walls and still can't find my answer. I am going to quote a wall for one of my customers and was needing a little help. This wall will run about 85' long, here is my question. If i were to tie a string from one end to the other, there is about a 2 1/2' difference in elevation. Does the base for the entire wall need to be at the same level, does this make it easier and is it usually what is the normal thing to do? The wall above grwond will actually be stepping down a little the more the elevation drops. So...... In my example with the 2 1/2' of elevation difference, I will end up having 2 1/2' of block under ground where the elevation is highest, right?

    Any advice will be appreciated!
  2. paul

    paul Lawnsite Addict
    Messages: 1,625

    No you need to step the wall up as you gain elevation. Remember to bury enough wall for the height that you need and overlap your steps.
  3. jdwilliams1

    jdwilliams1 LawnSite Member
    Messages: 97

    Paul, Thank You, Is there a standard inch to foot ratio for how much of the wall is buried in relation to how much is exposed
  4. steveair

    steveair LawnSite Bronze Member
    Messages: 1,073

    10% buried is the general rule, or in most cases where you are under 4 ft bury 1 block with most manufacturers. If it is higher, then engineering comes into play and they may note differently.

  5. Andrew Hardscape

    Andrew Hardscape LawnSite Member
    Messages: 37

    We bury 1-inch of base course for every 12-inches of wall height. (typical engineer specs) Although as a CYA we always completely bury at least 1 block no matter what the wall height is.

    And don't forget to start at the lowest point of the grade!
  6. Turfdude

    Turfdude LawnSite Bronze Member
    Messages: 1,899

    If wall is > 4' in height (exposed) make sure to get engineers seal as hydro pressure can be great and cause fail. This way you CYA as mentioned before.
  7. Andrew Hardscape

    Andrew Hardscape LawnSite Member
    Messages: 37

    Just a little note for anyone thinking about doing walls:

    You should always have walls 4' and higher should be speced and stamped by an engineer.

    Now that is a no brainer! But, where contractors go wrong is that is all that happens. To cover your rear end you have to have a rep. from the engineering company on site as the wall is constructed. The rep will perform compaction tests, and will monitor the soil as it goes in. If the soil is too wet or too dry, they will tell you how to proceed. If there is a problem 10 yeras from now, and you did not have an inspector on site, who signed off on the completed job, you CAN BE liable, even if you had engineered plans.

    This I know for a fact!MD's Finest
  8. Since I read no one has answered the ratio question, here it goes.

    First need wall hight?

    What builders?

    What size builders?

    But if you were starting with a wall hight of 3' with Versa-loc 6"

    Burry 1st builder half way

    Then when builder get burried 1.5 builders under ground level step up one so on and so forth. wont take long to go up. Also this is just an aproxamite rate. Check with the makers of the builders.

    This way you will be safe and over built for longevity and stability.
  9. jdwilliams1

    jdwilliams1 LawnSite Member
    Messages: 97

    thanks for the replies, I really appreciate all of your input. I know at times it gets old answering the same questions over and over, but I do appreciate it!

    Thanks, Jay

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