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Concrete Floor grinding - Any advice or tips?

Discussion in 'Renovation & Home Improvement' started by robbie_p, 24th Nov, 2015.

  1. robbie_p

    robbie_p Well-Known Member

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    Hi guys,

    As the slate has been removed from my floors, this Saturday I am going to be grinding down the concrete floors. I am going to hire one from Kennards - Meteor Concrete Grinder (Diamond Head) ans get a vacuum with it. Its about $450 for 24 hours.

    I plan to use 2 blades, one to remove the adhesive left behind from slate tiles, the other a finer blade for a smoother finish (if needed).

    As i have quite a tight schedule, is there any advice or tips you could give me? My plan of attach is as follows:

    Thursday - fill up any holes in concrete floor (any product recommendation?)
    Friday - remove any larger pieces of adhesive with hammer drill
    Saturday AM - 1st grind (35sqm) to remove adhesive
    Saturday PM - 2nd grind (35sqm) for finer finish
    Sunday - Seal concrete floors with 2 coats
    Monday - new kitchen installed

    Thanks in advance for any advice or tips.

    Cheers,
    Robbie
     

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  2. Depreciator

    Depreciator Moderator Staff Member

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    I ground a slab earlier this year in 'the reno I didn't want to do'. Prepare to be disappointed with the vacuum.
    Is there much adhesive left? The grinder will make short work of that. I wonder whether you need to get it off first.
    So you'll get the diamond blades for cutting and then the stones for grinding? It's not a hard job and there is less chance of mistakes and then tears than there is with sanding a timber floor.
     
  3. Scott No Mates

    Scott No Mates Well-Known Member

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    Get a twin head grinder (3 phase), wet the floor to keep the dust down.

    Use ardit as a floor levelling compound. And don't forget to use bondcrete.
     
  4. robbie_p

    robbie_p Well-Known Member

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    Why was the vacuum disappointing? I think im paying about $150 for the vacuum, so i hope it adds some value to the job.

    There isnt too much adhesive left. Its a cement based adhesive so comes off quite easily.

    I'm going to start off with diamond blade and see how it turns out before i hire the other blade for a smother finish, which is $100.
     
  5. robbie_p

    robbie_p Well-Known Member

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    My builder mentioned wetting the flooring, but the down side is you left with a "sludge".

    I am not sure if i would have time use a floor leveling compound?

    What do you use the bondcrete for?
     
  6. Depreciator

    Depreciator Moderator Staff Member

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    I would just let the grinder get adhesive off.
    The vac will collect some of the dust, but not as much as you would reasonably hope for.
    I had a go at wetting the floor, but once I was down a mil or two, the floor was bone dry.
    Ardit is okay for filling holes.
     
  7. Scott No Mates

    Scott No Mates Well-Known Member

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    Bondcrete seals the concrete & makes the floor levelling compound stick.

    Ardit goes off within the hour and cures reasonably quickly.

    I'd rather sludge than dust.
     
  8. robbie_p

    robbie_p Well-Known Member

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    So you saying i should first seal then use floor leveller?

    My idea was to:

    1: Fill holes with floor leveler, allow to cure
    2: Grind floors
    3: Seal floors (bondcrete or crommelin)
     
  9. robbie_p

    robbie_p Well-Known Member

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    So is the floor leveler only used AFTER you have ground and sealed floors?
     
  10. Scott No Mates

    Scott No Mates Well-Known Member

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    Ardit goes on a floor which is still wet with bondcrete - prevents a 'flash set'.

    It is a bonding agent/primer sealing the surface,

    Depending upon how rough your floor levelling work is you may need to grind the ardit.
     
  11. robbie_p

    robbie_p Well-Known Member

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    Spose there a few ways and a few products to use...

    The trade guys at Bunnings seemed to think you grind floors, level/fill holes, then seal..
     
  12. Depreciator

    Depreciator Moderator Staff Member

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    I think what Scott is getting at is that you put bondcrete in the holes you are filling first. It helps the ardit stick. Then you seal the whole floor over the top.
     
  13. robbie_p

    robbie_p Well-Known Member

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    Ah ok.. got ya!

    Either way.. you still need to grind first then fix holes :)
     
  14. robbie_p

    robbie_p Well-Known Member

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    Question...

    Does the floor leveler come in various shades which you can best match the colour of your concrete slab?
     
  15. Depreciator

    Depreciator Moderator Staff Member

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    I would overfill the holes first and then grind.
     
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  16. Depreciator

    Depreciator Moderator Staff Member

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    I don't think so, but there are dyes you can use to colour concrete/cement. A bit of mucking around given you are going to tile over the floor anyway.
     
  17. robbie_p

    robbie_p Well-Known Member

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    What do you think the cure time would be if i filled the holes first before grinding?
     
  18. Depreciator

    Depreciator Moderator Staff Member

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    A couple of hours.
     
  19. robbie_p

    robbie_p Well-Known Member

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    Ok great..

    In terms of surface preparation for a floor leveller... will a good sweep and a good suffice?
     
  20. Depreciator

    Depreciator Moderator Staff Member

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    So Robbie, you're just using the floor leveller to fill a few holes, aren't you? If you're doing a larger area it can be a bit tricky.
    If it's just holes, I would vacuum the holes, then use Bondcrete or a primer, then fill them. Overfill them so that when you sand the floor they will be level.
    The back of the packet will tell you much more than I know. I'm just a DIY guy.