Thanks Riles, I posted here in this forum because I didn't get any answers to the same post in the pool forum. It's already slipped to the 3rd page with nobody answering. So I hope to get answers here. The controversy over to seal or not seems to be a passionate one on some other stone sights. I practically got chewed out by one guy on another stone site. So I feel like I'm walking on eggshells a bit. He told me to "go do research and ask logical questions"...OUCH. I have been researching my butt off! It's just that all the "pros" answers are different! Yes, it does seem that filling travertine makes all the difference as to whether it's slippery or not. I am actually going to revisit Hartstone. I didn't want to go that route, but it seems like a safer bet. But travertine sure is beautiful. Good luck to you too! S

Moocat Thanks for the reference. I will give him a call. I am curious if your friends chose to replace the tile, or if they were forced to because it would be damaged when the coping was replaced. We have great old tile in perfect condition that you cannot find any more and want to keep when the coping gets replaced. But I was told by A&S that the tile could not be saved. It kills me but I also don't trust A&S. They also recommended replacing my underground piping since it is 40 years old and will go under the new decking. I will have someone else check it out but that doesn't seem unreasonable.

To install the stone coping I like to apply thinset to the top of the pool beam and buttered on the back of the stone with dry-pack in between to level. If you are only building up 1/2- 5/8" from the existing deck I would install in the same way. I'd be concerned about drainage otherwise.

The best and only way to fix that is tear out the old concrete, backfill and compact with Class 2 roadbase, install rebar according to the requirments of a licensed soils engineer. Make sure the rebar is 3"" off of the earth and repour the concrete. There is no good way to fix concrete except tear out and redo.