Any suggestions for concrete slab repair for floating floor?

[Fatsquare]

Hi, all. I just  move to  an house which is about 25-30years old. The living area is covered by old stone slab tile. It was uneven, large space between each tile which make the  floor really dirty looks. 

We plan to have the quickstep 12mm laminate floor. But I can't  put the laminate on the tiles. Because the tiles are uneven. So I have to remove all the slab tiles. It was totally a nightmare job: about 45 m2 slab tiles. And the adhesive is totally stick to my concrete slab. But finally I do remove all tiles and adhesive.

Here is the question:

1. Some minor adhesive still on the concrete slab. I try to use my tiny Bosch grinder with diamond grinding concrete cup wheel. But it will take a lots of time to finish it. Any commercial grinder machine for rent in Bunnings to let the job done quickly?

2. After removed all the adhesive, there are some patch need to repair. See the pictures there is some dent on the floor. How to repair the dent. Is that fixed by floor leveler? Actually I just want to fix the dent. I dont want to level the floor to much.( It is 45 m2 big areas to level.) Or can I just let it go, put laminated flooring underlay straight away on the concrete slab?

Thanks.

 

  

[EricL]

Hello @Fatsquare

Thanks for sharing your question about concrete slab repair. Your idea of using a grinder with a cup wheel is spot on. However, your aim is to just hit all the high spots on your floor. If there is excess glue that is standing too tall that has to be ground down. Don't worry about the dips as this will get filled by the compound.

As tempting as it is to just lay the floor on this unfinished surface, I recommend using self-levelling cement to make sure you have a flat even surface. Once the cement has levelled off you can do one last check for any old glue spots that you might have missed. A flat surface means that your floating floor will be flat as well.

My number one tip is to make sure that the floor is totally free of dust and debris before you begin using the self-levelling cement.

Here is a handy step-by-step guide: How to level a floor

If you need further assistance, please let us know,

Eric