Bedding Sand to level pre-cast wall block & pillar kit?

Discussion in 'Bricks, Masonry and Concrete' started by brianosaur, Aug 16, 2013.

  1. Aug 16, 2013 #1

    brianosaur

    brianosaur

    brianosaur

    New Member

    Joined:
    Aug 16, 2013
    Messages:
    2
    Likes Received:
    0
    Can I use a bit of coarse sand under a 2' high planter wall w/ pillars?

    I have the trench pretty well leveled with 6" of compacted RCA but when I test a few blocks of the first row I see some spots need a bit of tweaking. (perhaps 3/16" or 1/4").

    Does the wall block & pillars need to go directly on the RCA base or can I screed a bit of sand under it? I'm doing a patio as well and realize that a 1" bed of sand is needed under the pavers, but I'm thinking perhaps only about half that under the wall would really help me get it perfect. Yes or No?


     
  2. Aug 17, 2013 #2

    nealtw

    nealtw

    nealtw

    Contractor retired

    Joined:
    Nov 4, 2010
    Messages:
    23,891
    Likes Received:
    3,117
    I would do that with out thinking about it to much, but I have been wrong before.
     
  3. Aug 17, 2013 #3

    Drywallinfo

    Drywallinfo

    Drywallinfo

    Well-Known Member

    Joined:
    May 21, 2013
    Messages:
    152
    Likes Received:
    36
    Sand works well, but what you should do after you level it is soak it down good. Then compact it with a hand compactor. Check your level again and add sand as needed. Repeat wetting and compacting if you added a lot of extra sand.
     
  4. Aug 17, 2013 #4

    mudmixer

    mudmixer

    mudmixer

    Contractor

    Joined:
    Sep 9, 2006
    Messages:
    671
    Likes Received:
    76
    Too much sand is a mistake. Sand is not stable, since the temporary wetting and compaction will disappear in the long run.

    For paving stones (no dimension over 10"), the should be "set" in a screeded 1" maximum thickness of concrete sand on a compacted base. Follow up with a light fine (masonry) sand that is cast lightly over the surface and then a few passes with a vibratory plate compactor to draw sand into the tight joints and make the surface true. - Typical of real paver installations ranging from patios to streets and heavy duty installations of many acres.

    For retaining wall block, they are normally set on a compacted base, but up to 1/4 inch of sand can be added if necessary.

    Too much sand can be detrimental for strength and stability in both pavers and walls, especially when there are later rains and the pavers and walls can "swim" on/in the wet sand. - Typical internationally for pavers and retaining wall block.

    How do pillars fit into the picture?

    If you are using the larger "stepping stones", they are separated and allowed to move slightly with mother nature. If you are using common block dry stacked, you can expect them to move in the future.

    Dick
     
    GBR likes this.
  5. Aug 17, 2013 #5

    Drywallinfo

    Drywallinfo

    Drywallinfo

    Well-Known Member

    Joined:
    May 21, 2013
    Messages:
    152
    Likes Received:
    36
    Sounds like what you are putting in is pretty heavy requiring the best stability. Best to follow mudmixer's advice.

    What I did worked for my 3 ft pavers I put in 5 years ago but my sand was surrounded by our heavy clay soil and unable to move or dry out.
     
  6. Aug 18, 2013 #6

    brianosaur

    brianosaur

    brianosaur

    New Member

    Joined:
    Aug 16, 2013
    Messages:
    2
    Likes Received:
    0
    Pillars are part of the wall.
    6" Techo pillar block & 3" Techo wall block

    RCA base is close but 1/4" coarse sand would help tweak it.
    Thanks
     

Share This Page