Flowable fill as retaining wall base..

Discussion in 'Hardscaping' started by mrusk, Feb 7, 2007.

  1. mrusk

    mrusk LawnSite Gold Member
    Messages: 3,260

    Today i went to a techo bloc product showcase with out friend Paver Pete. He talked about using flowable fill for retaining wall base. I know alot about the product but never heard it used as a base material by itself. I know some people use it in raised patios, but it always seemed like they put road base on top of it.

    What do you guys think? Paver pete said its ok with NCMA.

  2. JRSlawn

    JRSlawn LawnSite Senior Member
    Messages: 640

    I hasve seen guys around here pouring there bases with concrete and laying right on top of that.
  3. D Felix

    D Felix LawnSite Bronze Member
    Messages: 1,898

    I don't really see any problem with it either.

    However, it is essentially just a very lean sand/portland mix. It's flowable, but don't believe any of the BS about it being "self-leveling".

    If you have a large area that needs to be filled with compacted material (i.e.- around a new inground pool), you can save a LOT of time and manpower ordering up the concrete trucks versus filling with lifts of roadbase. I've filled around pools using both methods, and I'd much rather call in the concrete trucks! We still put down several lifts of road base on top of the fill to lay pavers on though.

    Another consideration is there is a LOT of water involved in the process. It's gotta go somewhere after it's poured.

    I believe that is OK too, as long as it's a very lean psi concrete mix. Somewhere around 500 psi, IIRC. I could be wrong on that number though, but I know you shouldn't be using 3000+ psi concrete for it.

    The whole purpose of a SRW is to be able to flex. With a concrete base pad (if it's a high psi concrete), that flex is taken away and the wall will have problems down the road. Unless the base pad is poured as a true footer- below frost line.
  4. neversatisfiedj

    neversatisfiedj LawnSite Bronze Member
    Messages: 1,028

    Isn't it suppose to be a flexible base ?? What about cost ???
  5. D Felix

    D Felix LawnSite Bronze Member
    Messages: 1,898

    Flowable fill will be flexible. It's a high percentage sand/very low percentage portland mix with a LOT of water added in. What I was talking about not being flexible was actual concrete: sand, gravel and portland in the appropriate percentages.

    As for cost, I'm not sure. It will vary from supplier to supplier and from area to area, but I'm thinking that it's between $40-$60 a yard here. More than road base will cost, but you save on labor and time.
  6. Henry

    Henry LawnSite Senior Member
    Messages: 548

    Hey Matt, nice truck.

    I was quoted a price on flowable fill last year at around $145 per yard. Not cheap but definitely would be the faster way to go.
  7. D Felix

    D Felix LawnSite Bronze Member
    Messages: 1,898

    Ok, the $145 quote got me curious.

    Just called the local redi-mix supplier- Type 3 (whatever that means) is $53.20/yard.
  8. cgland

    cgland LawnSite Bronze Member
    Messages: 1,929

    I've had quotes ranging from $75/yd to $95/yd. Flowable fill is still a relatively new process and I am a little hesitant to try it yet, although I am biting at the bit to try it.

  9. D Felix

    D Felix LawnSite Bronze Member
    Messages: 1,898

    In my pool "scenario" that I talked about earlier, if you need to fill an area with 50-100+ yards of material, it is a HUGE time saver.

    Additional material costs may offset the need for less labor, but the prep work is essentially the same, and the time savings will allow you to be doing other things to make money down the road. Which should mean more profit in the long run.

    As ONLY fill, I'd use it. As a wall base, I think it would be more of a PITA than it's worth. You'd still probably need to set up forms to screed off of in order to get the base level. Which would be fine on a straight wall, but how many of those do you put in?
  10. mrusk

    mrusk LawnSite Gold Member
    Messages: 3,260

    talking about my truck?

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