Tiling onto uneven floor

[miksto]

I've used some latex self-levelling compound to even out a concrete floor prior to tiling. Unfortunately the surface hasn't ended up as flat as I was hoping, with ridges left in some places where the flow ended. I had to pour the self-levelling compound from two different corners of the room (because of a slight hump in the middle of the room plus a rise in the third corner) and was unable to get things to marry up cleanly in the middle. The result is somewhat disappointing, I have to say.

I've laid some tiles out without adhesive just to see how flush they fit to floor. Alas, in many cases there is a bit of wobble present rather than even contact across the whole surface area of the tile. Can I deal with this by varying the thickness of the tile adhesive or do I need to get the floor 100% flat before tiling, perhaps by pouring another coat of SLC?

I'm reluctant to do the latter, in case I end up with same problem as before and because the stuff is expensive. I’m tempted to see what I can do with the tile adhesive - if the worst comes to the worst and I end up with one or two cracked tiles I can always replace them - they're only cheap ones and I have quite a few spares, and it's my own property and I'm not moving out in a hurry. How quickly would a failure in a particular part of the tiling become evident and how easy is to replace a cracked tile should this happen?

Any suggestions would be much appreciated.

Thanks,

Mike

 

[Andy Allen]

What make of S.L.C did you use.

 

[miksto]

What make of S.L.C did you use.

It was Mapei Latexplan Trade

 

[jay]

pics might help with a strait edge to show prob and as above

 

[thomas]

you could use floor adhesive as s.l.c its the cheaper option?

 

[White Room]

Just do the slc again over the top of the existing

 

[doug boardley]

you could use a ptb adhesive (pourable thick bed)

 

[steve j sharpe]

Hi Mike i would pour another s.l.c again on top.http://www.tilersforums.com/images/icons/icon14.png

 

[kaharrison9]

Self level again Mike.This time using the plastic packers used when fitting windows.There will be all differant thickness's 2mm,3mm,5mm,10mm etc.Find the highest point of the floor and with a long level work out where the dips are and put the correct packer under the level to get the same height to the highest point.
I put the packer on a blob of Silicon to stop it floating when the slc goes down.
If a large floor say 30sm divide maybe into 3 and do 10sm at a time.Pour the slc and work it to the height of the packers.
Always have acheived a good result on very uneven floors this way.
Do check the thickness you can go with the slc

 

[Daz]

you could use a ptb adhesive (pourable thick bed)

I'm not sure if you are a DIY'er or Pro, but my experience of PTB is that it is not for the DIY'er.

I would have thought that another go with slc to take out the low spots would be your best course of action.