Help please. Pool built10 years ago. I currently have travertine tiles over sand base. Now lots of settling.

[Reveille5]

I'm in residential construction and familiar with concrete. I want to pull up existing travertine tiles, remove sand base to achieve a 3 1/2" deep concrete sub deck and reinstall travertine down with thinset to be same height as the coping tile. From what I researched, I have to keep the deck from touching pool coping and bond beam and fill with pool caulk to allow for expansion.

Any recommendations prior to pouring concrete? How to prepare the ground after removal of sand base prior to pouring? Do I need to place crushed stone as a base or just make sure sub surface is compacted?

4000 psi concrete? Place highway mesh for reinforcement?

Thanks so much for recommendations.

 

[proavia]

I can't help with best practices in how to accomplish your plan - but don't forget about bonding the new concrete deck and travertine to the existing bonding grid.

 

[Newdude]

For mine they poured the slab right on the grass/dirt. (Towards the end of my build thread in my signature).

The theory was it could crack and nobody would ever know because the pavers would hide it all. They moved the pallets of pavers all over with a bobcat and the slab didn't crack from 8k to 10k lbs driving around. It should have no problems supporting itself if the ground settles anywhere.

They laid the pavers directly on the slab without sand/mortar. The seams got polymeric sand which hardens after it gets wet.

 

[JoyfulNoise]

It depends on how much you fret over the details. The proper approach would be to remove all the sand and then DIG DOWN until you reach stable, compacted earth. Then you would backfill with a compacted stone base until you reach your desired concrete thickness. Steel mesh would be fine for reinforcement. You would apply either foam or asbestos liner at the pool coping edge to act as an expansion break. Then you can either reset the travertine tile using sand or thinset. If you don’t plan to have any gap in the tile, then polymeric sand joints aren’t necessary but it does require the travertine to be able to make a tight fit. The gap between the tile and the coping can later be filled with polyurethane caulk and sanded to match the tile. Do make sure you bring out several points of contact to the metal mesh for proper equipotential bonding with the pool and equipment.