How to lay travertine pavers?

[bow2021]

Hi there,

looking at laying some travertine pavers on our concrete slab patio. I’ve heard differing opinions on what to use for this. 
1) should I use a mortar mix as its natural stone?

2) use a thin set mortar mix (I’m not even sure what this is)

3) Some kind of tile adhesive?

my other question was should I seal the whole tile front and back, that’s something I’ve seen people talk about with varying opinions. 

thanks ☺️ 

 

[MitchellMc]

Hi @bow2021,

You'll find that if you were to tile over this area, moisture will be wicked up through the adhesive and grout and could present itself as efflorescence and white marking on your tiles. The correct way to prevent this is to add a waterproof membrane over the surface. The process would be to apply Sika 10kg Sikalastic Waterproof Membrane in two coats to build up a minimum of 3mm thickness. This product can be used over damp concrete. The distance you waterproof from the edge is up to you, but it should be far more than what the water could penetrate. Ideally, the whole slab should be waterproofed, as once the tiles are down and the sun isn't drying out the slab, the water could seep several metres into the slab.

Once the product is cured, you can add Davco 1L Davelastic Tile Adhesive Additive to Davco 20kg SMP Evo Tile Adhesive to adhere your tiles. For grouting, add Davco 1L 4 In 1 Grout Additive to Davco Sanitised Grout.

That should give you a solid solution which will prevent water and minerals from penetrating the tiled surface.

Please let me know if you have any questions.

Mitchell

[bow2021]

Thanks so much for this @MitchellMc. This is great. We won’t have any sun on the slab until spring so I was thinking I might have to wait all that time so this is a great solution. 

i did have another query. The slab itself is pretty even, except at the expansion joints. They raise up a few mm. So when putting a paver on there  they rock slightly. Will this be an issue when laying the tiles or will the adhesive help mitigate that? Would it be better to use wet mortar bed? Or is that not possible with the waterproof  membrane? 
thanks. 

[EricL]

Hello @bow2021 

That rise on the expansion joints has to be addressed before you lay the pavers down. I propose grinding the rise down with a Kango 125mm 8-Segment Spiral Diamond Grinding Cup or you could do it with a traditional cold chisel and break the high points off. The adhesives that Mitch suggested are safe to use over the waterproofing membrane. 

If you need further assistance, please let us know.

Eric

[bow2021]

Thanks @EricL 

I was thinking that a a wet mortar bed might be the way to go as I wanted to gain some height above our grass. Would this be ok over the top of the waterproof membrane suggested by @MitchellMc . That could solve the rise in the slab at the expansion joints as well no? 

[MitchellMc]

Hi @bow2021,

You can lay a cement screed over the waterproofing membrane. Just bear in mind that you can only build up a "wet mortar bed" so far before the weight of the pavers compresses it back down again. You might be best using a cement screed to level out the areas and wait for it to firm up. Then, come back over with your mortar bed.

Mitchell