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Securing a base with 4' of fill dirt?? picture

Discussion in 'Hardscaping' started by alexschultz1, Nov 27, 2011.

  1. alexschultz1

    alexschultz1 LawnSite Bronze Member
    Posts: 1,555

    so i have a new job where i am taking a

    back yard that slopes down hill, i am leveling off the bottom part and raising the top part and throwing a retaining wall in the middle. On the top part we will have a flagstone patio running almost all the way to the retaining wall. my question is how to i make sure the 4' of fill dirt i put in is secure so that it wont settle... Ive had jobs where i never have to raise the bed more than a couple inches, not a couple feet

  2. STL Ponds and Waterfalls

    STL Ponds and Waterfalls LawnSite Bronze Member
    Posts: 1,177

    Some fabric and grid with lot's of compacting. I just did a retaining wall that we spent 2 day's compacting the overdig. It was only 20lx6dx4down but it took a long time with my compactor just doing a few inches at a time. Hopefully you have access to a jumping jack or small sheeps foot/roller they will make life easier.
  3. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Posts: 6,417


    we use a trench roller. (I can post a pic if you need)

    and we usea small plate compactor along the 3' from the wall
  4. alexschultz1

    alexschultz1 LawnSite Bronze Member
    Posts: 1,555

    maybe i should have taken a little more time with the drawing bc the scaling is way off. That patio is going to be extended 20' out, so i have an area of around 20l'x35'wx4'd. how much dirt should the trench roller be able to compact at a time? just a rough estimate please, 3" or 12"
  5. STL Ponds and Waterfalls

    STL Ponds and Waterfalls LawnSite Bronze Member
    Posts: 1,177

    That's what I meant by a small sheeps foot/trench roller. This last project I compacted the backfill with my plate because I didn't have access to a trench roller and the area was a little tight. It wasn't fun doing 5 ft backfill at 2-3" at a time. Thank God it was nice soil.
  6. SVA_Concrete

    SVA_Concrete LawnSite Senior Member
    Posts: 467

    Or you can use clean 3/4 stone and not worry about compaction. Be sure to use fabric between that and your base for the patio as well as between the stone and the subgrade.
    Posted via Mobile Device
  7. BOEpavers

    BOEpavers LawnSite Member
    Posts: 93

    From a time standpoint I would recommend backfilling the wall with all aggregate. We did a large raised patio about 5' from the lower patio. Started with approximately 2' of number 4 stone, then about a foot of number 3, then Mirafi, then about 12-18" of 2B, then Mirafi, then 6" of 2A modified, sand, pavers. Quickly compacted the #4 and # 3 stone to set them, spent more time compacting the 2B, then normal compaction of the 2A modified. Been about 4 years and nothing has moved. Have worked for the customer about every year since install so I see the patio at least that often. Aggregate is also less expensive in our are than good fill dirt and I think less work and more dependable.
  8. STL Ponds and Waterfalls

    STL Ponds and Waterfalls LawnSite Bronze Member
    Posts: 1,177

    I thought about doing the same, but it actually came to a draw between trucking in stone or reusing on site soil. The reason for me was not having to truck soil out of the site. Each project will determine if it's cost effective to excavate and remove soil than pay to have stone trucked in etc etc.

    It all depends on the scenario, but it is so much quicker to use clean stone vs soil in my eye's depending on the numbers.
  9. alexschultz1

    alexschultz1 LawnSite Bronze Member
    Posts: 1,555

    i dont think my clients have to budget to fill in an area 20' wide by 35' long and 4' deep with aggregate. i think a trench roller will work, but how long should it take to compact an area that large. im just trying to get my numbers together to get this bid finalized. i need to submit this bid by wednesday morning so any help with some numbers would be amazing. Thanks for your help though, im not trying to be rude if i am coming out that way.
  10. SVA_Concrete

    SVA_Concrete LawnSite Senior Member
    Posts: 467

    i was under the impression you were filling the area anyway. not that you had to excavate that out for construction of the wall.

    a. you don't own a trench roller -- rental, delievery and pickup costs
    b. you have not compacted this much fill before -- learning curve
    c. truck in stone instead of sand and forget about it. you can install 7 loads of stone in less time than it has taken you to figure this job.
    d. we are in the winter months, think of the savings of having stone under your patio, rain... freezing... bleh no problem with stone that DOESN'T HOLD WATER!! :)

    im not a certified LAWN pro, so take my opinion for what its worth.

    if it is available in your market look for recycled number 3 stone (construction entrance stone) it should save you $$ over virgin stone.

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