Sealing the front and back of Limestone tiles - Tile Advice

[vman]

Hi ,

I am about to start my tiling project, it's quite large at 60m2.
I have underfloor heating that I put in 6 months ago and concrete has been down this time to and heated up so all good.
Anyway I have large module Limetone floor tiles (900x600).
I have bought Durabase membrane roll and Mapei Keraquick Tile Adhesive White - 20kg. After speaking to a friend who tiles he said seal the front and the back of the tiles before laying (Lithofin MN Stain Stop Natural Stone Impregnator & Sealer).
Is this overkill or a good idea!?
Is Mapei Keraquick Tile Adhesive White recommended for stone, it looks like it should do the job after researching?
Also can someone recommend grout spacing to leave, they are tumbled so slightly rustic!?

Couple of pictures
Thanks
Rob

 

[Dave]

If it was a pure white limestone then i agree but with that Jura beige , I’ve never sealed the backs on them .

 

[vman]

Would you think 5mm spacing would be about right for these?
[automerge]1607092106[/automerge]
Looks like CTD do pots of 4mm so maybe that.?

 

[Dave]

Would you think 5mm spacing would be about right for these?
[automerge]1607092106[/automerge]
Looks like CTD do pots of 4mm so maybe that.?

I use 3mm but 4mm would be ok

 

[Macster]

I literally came here to ask this same question, i have the exact same tiles to the same measurements. When are you installing yours?

Think i am going to do 4mm tile spacers also because thats the biggest i can find with the tile leveling wedges.

 

[Bond]

6mm for me.

 

[Rae]

3mm ,never sealed the backs going to get back buttered ,nice stone

 

[Macster]

Another question ive just thought of actually do you know what grout you will use on these or does anybody know some to recommend? Cheers

 

[Dave]

Another question ive just thought of actually do you know what grout you will use on these or does anybody know some to recommend? Cheers

Preferably a fast setting grout. Weber pro snd mapei ultra are two i use.

 

[vman]

Another question ive just thought of actually do you know what grout you will use on these or does anybody know some to recommend? Cheers

I bought some grout from the tile importer. It's there own make.
It says it is Flexible, water repellent, suitable for natural stone etc oh and it's beige!
Hoping to get started xmas holidays.

Spacing seems to a personal preference , the tile shop lads said 3mm, the showroom I bought the tiles from said 8mm! The showroom said the larger size was due to the tumbled edges. I didn't buy any as I still haven't decided....