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Tips For Building Retaining Walls

Discussion in 'Hardscaping' started by SEALAWNMANAGEMENT, May 25, 2008.


    Posts: 74

    I have done a few walls at this point but I was wondering what are some of the tricks of the trade when it comes to retaining walls. Books are good references but I was wondering what are some tips to make things go a little easier. What are the best types of equipment to use? Best types of base materials? and anything else that is good to know.
  2. 4 seasons lawn&land

    4 seasons lawn&land LawnSite Gold Member
    from NY
    Posts: 3,597

  3. ropinghorns

    ropinghorns LawnSite Member
    Posts: 72

    We use RR Ties,
  4. ropinghorns

    ropinghorns LawnSite Member
    Posts: 72

    We also set them in place with the excavator and thumb [they are heavy].
  5. 1wezil

    1wezil LawnSite Senior Member
    from tn
    Posts: 535

  6. meador56

    meador56 LawnSite Member
    Posts: 90

    When we started we were asked to do some small walls only 3 or 4 rows high and books plus manufacturors info. After being approached about bigger walls we went and took the classes and became certified. After doing the hands on with simple walls a little training goes a long way.
  7. JimLewis

    JimLewis LawnSite Fanatic
    Posts: 6,841

    I agree with Meador that training is really the key. Take some certification classes, when you get the time.

    Also, find out who your local rep. is for your wall block supplier. Reps are great. They are there exactly for this reason. Call your local hardscape supplier and tell them, "Hi, this is Jack with ABC Landscaping here in Portland. Who would be my rep. for your retaining wall blocks?" You didn't even know you had a rep., did you? Well you do. Get to know him. Meet with him and he'll help you with all of this. There's nothing wrong or embarrassing about being new at this. Don't feel like you should already know or be afraid to ask for his help. That's why he has his job - to help contractors. He can help you in terms of bidding and even installing. My rep. actually came out and spent a day with us teaching us installation tips back when I was still new at these.

    Aside from that, it doesn't seem that any of the responses so far were all that helpful, so I'll give you a few tips...

    I assume you're referring to a segmental retaining wall (pre-formed concrete blocks), right? Because my advice here is tailored toward that kind of wall.

    First, understand that base preparation is the key to any good segmental retaining wall. There are other important aspects, but this is THE most important part. You'll want to prepare a base of gravel. The depth of the gravel depends on how tall the wall is going to be. Find out how much gravel you need. The entire area of the gravel base needs to be under grade. And it will need to be compacted very well. Preferably with a plate compactor (you can rent them cheap) but if that won't work, get yourself a hand tamper and tamp the rock down until it is very compact.

    Your base blocks need to be buried at least partially under grade too. How deep again depends on how tall the wall is and what brand of block too. But at least a few inches under grade. Sometimes you bury the entire first course under grade. Make sure each block is installed perfectly level. Level side to side, level front to back, and then use a LONG level to make sure they are level from one to the next over a course of about 5 blocks. This part is really key

    If the length of the wall is not level (which is usually the case for us) then you want to start your wall at the lowest point, and then stair step up as needed.

    You'll typically spend 3-4x as long preparing the base as you will stacking and backfilling. For instance, a typical wall for us we will spend 4 days just preparing the base blocks and then the final day or two is spent stacking and backfilling.

    Be sure to install proper drainage behind the wall, as in this photo;


    There are a lot of other things to take into account when installing segmental walls. Things like global stability, surcharge, soil type, geogrid reinforcement, etc. are all things you need to learn about. But I've given you some pretty good basic tips there.
  8. Paradise Landscapes

    Paradise Landscapes LawnSite Senior Member
    Posts: 960

    What jim Lewis said.

    Say Jim, is that from the Versa-Lok installation manual?
  9. JimLewis

    JimLewis LawnSite Fanatic
    Posts: 6,841

    LOL. No. I don't think we even had a Versa-Lok distributor in our area. I've seen that kind of block in the trade journals before but we don't use it around here, that I know of.

    It came from experience and also my AllanBlock Certification classes. Which are free, by the way....

    Posts: 74

    Thanks for the info Jim. Where would I find classes for installing walls.

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