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Repairing block wall using cement?? Help please

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  • Repairing block wall using cement?? Help please

    Hello, I have a small section of a block wall that was damaged, I'd like to repair by building a form using plywood and pouring concrete. Do you think the concrete would stick to the existing blocks? See pic. I think it would be the easiest way to make the repair. The existing rebar is loose, should I secure the rebar before pouring concrete to help support the concrete? What would be the best material to use, quickrete, concrete bags, etc? Thanks in advance for the help, Al


    block wall.jpg

    Attached Files

  • #2
    I'd drill some Tapcons, expansion anchors or epoxy some rebar into the existing solid sections. Probably 8 or 10 of them. Be sure that the outside ends of whatever you use are minimum 2" back from face of new concrete if they're galvanized, 3" if they're uncoated steel. Clean out all the residue of pieces, dust , etc. and then vacuum or blow it clean.
    Coat all the existing surfaces with a bonding agent. It's available at Lowe's or HD. Clean off existing block where plywood will bear on. You could use some clamps at the bottom and top and Tapcons or stakes to keep new concrete from seeping out. I'd use the 5000# bag mix you can buy at L's or HD. Dampen the existing concrete according to instructions on bonding agent container. Coat the inside of the form plywood with oil or a release agent. Mix the concrete thoroughly with about a 4 or 5 slump. Shovel concrete into form staring at the bottom and filling as you go. Once you start pouring keep going (no lunch or breaks) and rodding the newer concrete into what 's below it. Tap the sides of the forums to consolidate concrete and avoid honeycombing.
    Remember whatever the inside surface of your form plywood looks like is what your finished product will look like when you remove forms. If you want to go through the effort you could replicate the block mortar joints by fastening concave pieces onto your form where the mortar joints in concrete are on the existing wall. Once the concrete has set sufficiently you could pull the forms and sponge float the face of the new concrete which will match the existing block better than smooth concrete.
    I don't believe it's necessary to fasten existing rebar as long as it's not too close to top or sides of your new form and it is solid where it enters the existing wall.
    The line between the new and the old will always be visible but if you do it right it will look good and last a long time.

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    • #3
      I would rip out that section and redo it with new block. Faster and cheaper than any other method. It would take my mason a couple of hours.

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      • #4
        Originally posted by dgbldr View Post
        I would rip out that section and redo it with new block. Faster and cheaper than any other method. It would take my mason a couple of hours.
        I believe you have the best solution.

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        • #5
          Originally posted by dgbldr View Post
          I would rip out that section and redo it with new block. Faster and cheaper than any other method. It would take my mason a couple of hours.
          This ........
          When you've got them by the balls, their hearts and minds will follow.

          Theodore Roosevelt

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          • #6
            What dg said, and, have the guy who damaged it pay for the repair....assuming it was not you.
            Portland Renovations, Inc.
            www.portlandrenovations.com

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            • #7
              Thanks Ablesupe, great advice. Your plan is something I can do without hiring a mason. I appreciate the advice!

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