REPAIR Hole in concrete floor first before using leveling compound to smooth level the floor

[MissBuilding1975]

Hi Guys,

looking to tile my new kitchen floor, however, have come across a hickup, There is a very large hole in the concrete floor from wall to wall which has collapsed slightly. I don't know why this has happened though my suspicion is that the builder who did my extension years ago knew this when building the foundation but rather level the floor entirely he decided to compensate that via using a lot of tile adhesive instead and then lay the tiles. Luckily the rest of the floor is levelled except that little dip after removing the kitchen tiles

Anyways I would like to fix this. My plan of action is to fill the hole with a thick concrete cement mix and screed this back to the floor level where the kitchen floor meets again at the level point. Once done so, use the excess cement mix to patch up any small holes.

My question is after an hour or 2, can then pour a self-levelling compound to just smooth the area with my trout or do i have to wait till the concrete cement mix for the holes to harden first over 24 hours, before pouring a self-levelling compound? I have included some pictures below relating to my concerns above.

Thanks in advance for all that replied.

 

[Doggit]

Depending on the depth, you'll need to leave it for at least a week or so. You can get SLC that will fill to 2", and that will do the job quicker. Set screws in the floor to find your level using a long spirit level, and then use a slightly wetter mix than recommended, but not much. Do the hole first, and then the whole room in one go.

 

[MissBuilding1975]

@Doggit thanks ever so much doggit for your response I shall do the above as recommended. Regarding the holes, I am having a bit of a nightmare removing all dust from the floor surface because the floor is bumpy I can't hoover.

1. Is it essential that I remove all dust from the surface? Is there any other way of doing this quickly, tried broom etc..

2. Should I seal the holes before applying the concrete? Like a pva mix or should I buy one of them adhesive sticky liquids which mixes into the concrete mix and apply that directly to the hole, bearing in mind the is still dusty? Your thoughts on this please. What state should the hole be in before applying the concrete back?

This goes for the whole floor too, when I then put the self-levelling compound on.

Ever so great full for your response.

Thanks again.

 

[Doggit]

You remove as much of the dust as possible, then you apply an acrylic primer to seal in the rest. If you do the job in two stages, then prime the hole, and fill it, then prime everything before the final layer.