Help with prep.

[Khall]

I am new to the forum and new to tiling. I am awaiting delivery of 600x600 porcelain tiles which are to be laid in our kitchen dinner. I am looking for advise on preparing the floor to ensure that things go well and last.

The floor is split into three sections. Part old quarry tiles that had been tiled over with ceramic tiles which I have now removed. The other two sections are concrete floor. One which is raw concrete the other which is mainly raw with small sections of what looks like paint.

All the sections are solid and in good condition. What I want to know is:

1) do I need to do anything to prepare the concrete sections? (sand off paint, seal)
2) What is the best way to clean the quarry tiles? (they have been exposed to standard kitchen use for several months)
3) Part of the concrete has a smooth finish will anything need to be done to ensure a good bond?

 

[Andy Allen]

can you not take up the quarrys too?, and yes paint needs removing..

 

[Khall]

I could but it seems to make sense to keep them there as the concrete floor has been levelled to the same level as the quarry tiles. They are solid and go under the kitchen units so would be a nightmare of a job. Also they are so solid that I worry that more damage will be done trying to get them out.

Unless there is a specific reason to remove I would rather leave them there.

 

[Andrew]

The transition from concrete to quarries will be an issue.
Without knowing the condition of the subfloor beneath the quarries and the certainty of their bond to the subfloor this is also a risk that could cause your new floor to fail.
once you make a decision and start to tile, there are many factors to consider to guarantee a successful install
make sure screed is dry, test it properly
prime not pva
I always butter the backs of porcelain as well as notch the floor
etc..

Good preparation is the nightmare part of the job, but once it's done and done properly, the rest of the job then becomes a pleasure!

Good luck!

 

[Khall]

Thanks for your thoughts Andrew.

What is the risk of the transition. Is it simply a movement issue? ie one could move more than other therefore cause cracking?

When you talk about screed are you referring to the concrete floors? They are years old and well and truely dry!

When you say prime are you meaning just the concrete or both concrete and quarry?

I know what you mean by buttering but do you do this with a smooth or noted buttering? Also what is the reason for this is it simply to ensure a better bed? What sort of thickness of butter would you go for on 600x600 porcelain?

 

[Mike Mike]

If that was my floor, and the quarry tiles are fixed firmly, I would sand it all with a rotary floor machine, prime it with an acrylic primer (including the quarry tiles), and then give it a thin coat of smoothing compound (similar to self leveling but can be spread much thinner, needs to be troweled, and leaves no laitance) to get it nice and flat. I'd then give it a quick sand again and fix a de-coupling membrane (like Dural or Ditra) over the whole area, then tile onto that with a flexible adhesive, such as Mapei Mapeker from Screwfix for £14.99 a bag.