Garage floor tiling prep/install advice - Tile Advice

[bicurl]

Moving into a new build property in the near future so planning the 33 odd sqm garage space.
Will be used for restoring individual cars so want a durable, permanent and comfortable space - Heating is another conversation

Have opted for Dotti porcelain tiles - 300mmx300mm (grade 5, non slip, full through tile)
Previously had experience with Epoxy flooring but want to try a different option this time around.

Looking for some sound advice around the laying/prep required for the tiles, as some tilers/quotes have differing opinions about the laying of the tiles;

Garage is under the main master bedroom, garage walls/ceiling will be insulated and plasterboarded and looking to get an insulated door over the standard non version that will come with the property.
The concrete base has a DPM layer and trying to understand from the builder if there is an insulation layer down there too.

One tiler would opt for; 6mm insulation boards with an anti fracture matt then tiling on top.
another;
No insulation boards and matt layer required and tiling on a solid bed using a non void trowel using flexible tile adhesive - Will add an expansion joint in the middle along grout route/gap - They would also seal the porcelain tiles

Conflicting info gets me thinking, what is the best solution here - any advice would be appreciated.

 

[Anthony]

Might need to prime and self level it. concrete is usually very uneven. Then tile straight over it
No mating or boards required.

 

[Steve6690]

Definitely the second option - as Anthony recommends.

 

[bicurl]

thanks for the replies.
The concrete base will be relatively new.

Are you sure direct tiling to the substrate will not in the future cause issues with concrete movement etc..

I am no expert, just wanting to ensure that it is done correctly.
Again thanks for yout input.

 

[Steve6690]

If that's a possibility you could install an uncoupling membrane such as Ditra. I wouldn't trust tile backer such as kerdi or jackoboard to take the weight of a car but i could be wrong in that.