Novice building a retaining wall: Pics and drawings included

Discussion in 'Hardscaping' started by blkhawk661, May 21, 2012.

  1. blkhawk661

    blkhawk661 LawnSite Member
    from KY
    Posts: 16

    I am renting an excavator this weekend to take advantage of the holiday and I intend to start a retaining wall. I really appreciate getting some of the expertise from fellow board members.

    Below are pics and a rough drawing of the back yard. My questions are such:

    1) Changing elevations: If I only built the wall to the height of the current terrain i'd be changing the level of my base multiple times. Which doesn't sound right. Given my lack of experience, should I just make the the base the same throughout? I hesitate to do this given additional dirt removal and cost.

    2) Drainage: I had planned on using a single PVC pipe behind the base layer running the length of the way and draining on the far side away from the patio. Open to the air by point F. Additionally, 12 inches of gravel will be placed behind the wall per mfg specs. Is this sufficient drainage?

    3) How do I over build?: I plan on being in this house for some time (perhaps 50 years) and later building a paver patio on top of it. My son will play on this, so I want it to be fail safe. I plan to use geogrid every other level starting with base and bury the entire first layer. Is reasonable? Any other considerations I should make?

    4) Stairs: I tenatively would like to put stairs in between points B and C (though not 12 ft wide of course). Do i need to dig out that entire area or just step cut with new levels of base? Any special drainage requiredments?

    Many thanks to all that reply.

    Other pertient information:
    - i chose the base of the tree as the target height becuase the base of the cement pad is even higher and would require a much taller wall. I am not tied to this though.
    - climate is northern KY (clay soil)
    - product I plan to use is Mesa Block - Standard unit block since I can get it for $5.60 a block. Dimenstions are 18x12x8
    - since I am impatient and cheap, I have not consulted a civil engineer

    Questions comments? Any other considerations I should keep in mind?

    Wall 1 edited.jpg

    Wall 2 edited.jpg

    Wall 3 edited.jpg

    Retaining Wall Overview 5-21.jpg
  2. shovelracer

    shovelracer LawnSite Silver Member
    Posts: 2,009

    Adding stairs will greatly increase your time spent and also your cost. They also are more difficult to do properly. The wall will be 4.5' tall correct? This makes for a heck of a fall off the top. Will you be fencing it in? Perhaps you might want to build a double tier wall below the stairs and a single above. You can just lay a single elevation layer and it is generally faster and easier, but you will bury probably 2 pallets worth of block. Maybe just want to make a few steps of greater elevation.

    All this said it generally is not recommended to build a wall of engineer required size your first time out. At least if you forked out a few hundred for the engineer you would know what certain dimensions to use. Sounds like you could pay for it out of the money you intend to use for overuse of geogrid and buried stone.
  3. SSmith

    SSmith Banned
    Posts: 447

    The amount of fill is going to be massive. Do not use pvc....use drain tile. I'm in Cincy and I feel like I should help you, but it's a holiday weekend and I'm taking it all off. I have a small child too and a soft spot in my heart for DIY's even if it means one less potential customer. If you plan on taking a while to finish this project then feel free to pm me and I can consult with you....maybe even drive down there and take a look.
  4. blkhawk661

    blkhawk661 LawnSite Member
    from KY
    Posts: 16

    I think my low post count restricts my ability to pm. Nor can I reply to pms( or at least I can't re: to the admin's pms)

    If you pm me, then I will happily email or call you. I appreciate your generousity with your time.
  5. blkhawk661

    blkhawk661 LawnSite Member
    from KY
    Posts: 16

    No, I was going to plant rose bushes or boxwoods as a deterrent. My boy is only 14 months and nothing will completely prevent him from always being covered with bruises.

    Agreed, but my decision to do this was recent. The equipment rental store is only charging 1.5 days for 3 days since they are closed for the holiday. I have the time and I was getting a deal so I switched into "obsession mode" .

    So here I am. Trying to learn how to build a wall, buy the materials, rent the equipment and start building it all in a weeks time.

    FYI - last week I didn't know how to use a chain saw and I ended up buying one for cutting down a 60ft tree that was 30 ft from my house. (the stump in the pics)

    I don't have hobbies, i have obsessions.
  6. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Posts: 6,417

    drainage chimeny should be no less than 18-inches wide.

    with equipment rantal and all - it'll cost you more to do it yourself than paying a competent contractor :)
  7. SSmith

    SSmith Banned
    Posts: 447

    I can't even pm you. I believe you need 10 posts is all.
  8. blkhawk661

    blkhawk661 LawnSite Member
    from KY
    Posts: 16

    oh geez. I just googled "drainage chimney" and I had no idea. I thought drainage was just going to be pvc or drainage tile with was backfilling 12'' of gravel.

    $300 for the excavator, and maybe $200 for my cousins to help me out.

    You really think I can find a contractor who will put in such a long wall for only around $500 in labor?
  9. blkhawk661

    blkhawk661 LawnSite Member
    from KY
    Posts: 16

    half way tempted to cheat the system to get to 10
  10. SSmith

    SSmith Banned
    Posts: 447

    There probably are a lot of "beer money" guys who'd do it for that!

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