20mm Porcelain Tiling on Concrete Slab

[Tim C]

Hi everyone,

 

I am looking for some advice and product recommendations for laying 20mm 600x600mm porcelain tiles onto an external reinfoced concrete sub base patio/path. There doesn't seem to be to much info online for this method as most folks go with a sand/cement bed

 

There are two sections, the first is 40 sqm rectangle and the second is a path of about 20 sqm (2 m wide).

 

Here's what I was thinking:

• Plane the concrete which is currently a bit lumpy in places
• Apply primer 
• Level where needed with Keroflex LevelFlex External levelling compound (i.e. not a latex product)
• Use an S1 tile adhesive such as KeraKoll Setaflex standard (would S2 be better?)
• Grout with Ultrascape flowpoint

 

Wasn't sure if I need to factor in some expansion joints on the main 40 sqm patio (4 x 10m), but could easily do this. 

 

Thanks for any advice, tips or product recommendations!

 

[Nickfromwales]

I’d prob just level and lay with the adhesive, if the bumps aren’t >5mm. 
 

Other than that you’re on the right track. 
 

If the tiles are dark and get a lot of sunlight you may need to put one expansion gap in across, to divide the longest length.

[Tim C]

Thanks Nick, that’s reassuring feedback. 
yes, tiles are dark grey and the patio is south facing so certainly get’s warm. In fact, was like the surface of mars yesterday as I was planing the slab, so will factor in some expansion joints.

 

if anyone else out there has product recommendations then that would be appreciated before I purchase a lot of materials. 

[Andehh]

Anti crack mat for sure! We installed one, and still see a few cracks in the grout which need redoing, but touch wood no other issues.

 

Similar sqm to you, laid in 75mm ish sand and cement.