Hollow block infill and mortar

Discussion in 'Builders' Talk' started by thedavidm, Apr 21, 2019.

  1. thedavidm

    thedavidm New Member

    Evening all.

    I've put in footings for a small retaining wall in a garden The wall is to comprise a single course of hollow blocks, topped with a decorative brick. The footings are have rebar (vertical) for the blocks.
    I was thinking of saving time by mixing a finer concrete mix (using horticultural grit or pea gravel and sharp sand) not only to fill the block cavities but bed the blocks onto the footings as well. I wondered what the adhesion of concrete is compared to mortar....would an additive help? Comments?

    Many thanks
     
  2. sospan

    sospan Screwfix Select

    you will find it hard to level the blocks if you have any from of stone in the mortar mix. It is best to lay two courses of block and then infill with a concrete mix. Horticultural grit / pea gravel is very expensive compared to traditional aggregate.

    You should also install horizontal rebar every few courses which should be tied to the vertical rebar and don't forget to fit the weep holes and back fill with clean aggregate as you go
     
  3. KIAB

    KIAB Super Member

    It's only a single course Sospan,so wouldn't think you need the horizontal rebar.

    Horrible things hollow blocks, lay them, give it a couple of days to harden before filling blocks with concrete.
     
  4. sospan

    sospan Screwfix Select

    missed the single course bit :oops:.

    I possible forget getting the hollows and just put blocks on flat
     
    KIAB likes this.
  5. KIAB

    KIAB Super Member

    Lay blocks flat everytime,easier,quicker.:)
     
  6. thedavidm

    thedavidm New Member

    Thanks both for your replies. I'll revert to plan A - mortar then infill with standard concrete mix.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice