Floor Tiling On Concrete - Several Questions About Floor Prep and Laying

[EdMac]

Hi

We've knocked through our kitchen and dining room and taken up old stone/porcelain tiles in the kitchen and carpet in the dining room. There are several questions I have before I start tiling.

Here is a share link to a Google Drive folder with images: Tiling - Google Drive - https://drive.google.com/open?id=1S2VjLvGCncb-S9F_YU-DRGE3hKUe0sGd

The issues are as follows - following the numbering of images:

1. When I took the dining room carpet up there was what looked like a leveling compound under the underlay. But obviously, with no protection from traffic, it has crumbled in places. I think it was there because there were some very light pocks in the concrete / or it's just standard practice. It has been down since the house was new 20 years ago. I have got most of it up but there are patches remaining where it is 1mm thick.

Question: is it OK to prime and tile over these patches that remain? (They are firmly bonded to the concrete.)

2. In the kitchen I took up tiles and tile adhesive and under that was a cheap laminate that was cracking so I took that up. The adhesive underneath is like concrete itself. I've chipped most of it up (hired a tool but it wasn't that effective) but there are patches up to 2mm thick remaining.

Question: is it ok to prime and tile over these patches.

3. Between the kitchen and dining room was a wall we were told (by a neighour) wasn't load bearing but it was. There is a row of engineering bricks in the floor that the wall 'sat' on.

Question: my plan is to removed plastic covering bricks, fill cavities in bricks and level with the concrete floor on either side - bricks are about 5mm lower. Is this an acceptable plan and if so what is best to use to fill and level given I will be tiling over them - could I use a quick set like mastercrete - which is easy to work with.

4. Where the dining room meets the living room I plan to tile up to the separating wall on the living room side. At some point, I will put down a wooden floor in the living room.

Question: I will need to insert a metal or wooden strip between tile and wooden floor - what is the best way to leave the tiles now to make this easy to do in future without having to take a row of tiles up - usually the strip inserts under the tile. At this point, I don't know what depth the wooden flooring will be.

5. Where the dining room floor meets the patio door to the garden the concrete floor drops by about 5 or 6mm (once I've removed the failed levelling compound).

Question: I don't really want to put leveling compound down. Can I just make up that 5mm with a bit more adhesive? The drop away starts about 6cm from the door.

Other details:

- pics 6 & 7 are the Benfer Primer (I plan to roll that onto the floor) and the Benfer slower setting adhesive.
- The total floor space is about 20m.
- Tiles are porcelain 59x59cm
- I am using a TileEasy leveling cap system

My plan is to give a final scrape on the concrete (there will be no friable bits left), hoover, mop away any remaining dust (twice), let dry and then prime, leave overnight and begin tiling.

Thanks for any help received!!

 

[Spare Tool]

Why wouldn't you want to make life easier and put down a leveling compound over the whole area, fresh new level playing field to go at. If your after a seemless finish between the floors before doing anything you really need to have a tile and wood sample to hand as this dictates your substrate heights..

 

[EdMac]

Hi Andy - Thanks for comments. I had just hoped to avoid a self-leveling compound if possible. Firstly because if that goes wrong I've got yet another layer to take up and secondly the cost of covering the entire 20m area.

Edited to add - I've just had a look at the floor and the concrete is nice and flat, there are just patches of adhesive bonded to it - but only about 1 - 2mm thick and not at all friable. So if I can tile over that I'd rather.

Maybe I can use the leveling compound to raise by the patio door and cover and level the row of engineering bricks.

So the key question is - is it ok to tile over concrete with patches of strongly bonded adhesive that is 1 to 2mm thick.

 

[Flintstone]

2mm thick areas of adhesive will be a pain when tiling.

 

[GoneGuy]

It’s all about the prep work for tiling, if you do as @Andystiletiling suggested and put a self level over whole area this would also fill in any voids that you have and make the whole floor nice and flat and will make it so much easier to lay your tiles.

 

[EdMac]

I've continued to scrape up old adhesive and I'm down to practically nothing now. A combination of Big Mutt Pro, Garden Half Moon and an old putty pallette. When I lay a straight edge down any 'low points' are negligible ie. they won't even be felt under the trowel.

Question now is whether to fill engineering bricks:
3.engineering-bricks-between-kitchen-and-dining-room.jpg - https://drive.google.com/file/d/1Vo5_TqVioYpcSjXZv-Pbiso6ggc6Y4nT/view?usp=sharing

and then level over those (a 1 or 2mm difference to floor level) with a leveling compound? And if so what to fill them with?

 

[EdMac]

I've also checked out the galleries on tiler's websites and I see they are tiling over worse than my floor with no SLC (including tilers on here... 😉 )

 

[Time's Ran Out]

Advice on this forum will be given in good faith and with the best practices currently available.
If you wish to ignore in favour of other sites or members photos then that is your prerogative.

 

[Dumbo]

Advice on this forum will be given in good faith and with the best practices currently available.
If you wish to ignore in favour of other sites or members photos then that is your prerogative.

See now I was going to say something like that but all I could come up with was "Good luck "
So I didn't

 

[EdMac]

But it's difficult to assess when it's the people giving the advice who are clearly not following it themselves - as evidenced by the photos on their websites. The answer to all questions cannot be "put a self-leveling compound down". I've checked my floor with a spirit level - it is perfectly level. Putting a self-leveling compound down introduces an unnecessary step that could fail.