Stone waterfall needs repair and sealing

[Vinyl_Guy]

Without actually seeing it, it's really hard to tell but......

There's probably two schools of discipline. Caulk or a mortar type solution.

If it's a mortar type solutions you'd be looking at some kind of water plug, hydraulic cement, or what is generically referred to as Thorite . Most can be found at your local Home Center. They dry extremely fast and probably won't match the "joints" they fill, as they are usually darker then any typical mortar. I've seen hydraulic cement stop leaks while they are actually occurring. So if you can shut the water off and apply it you might have a good chance at sealing the cracks.

I've used a lot of products from this major company: Thoro

The other is probably a caulk type solution. There was a "marine" grade caulk I used in very limited situations (temporary solutions), that was pretty good, but I forget the exact name of it . But it was described like that "marine grade" caulk. It might have been this: 3M Marine 5200. Probably going to be fairly unsightly as it's not going to match the mortar joints in between the rocks at all. And was nasty stuff. Think marshmellow that sticks like tar to things. It was brutal to work with.

A two part epoxy joint sealer like Deck-O-Seal (generic term) used for gaps in pool decking or something similar might work. But it's not very viscus so it's hard to apply on anything other then flat horizontal surfaces. Again very nasty to work with, doesn't come off anything it gets on very easily. Can get unsightly very fast if your not careful.

Again with out seeing it, those are my thoughts.......

Good Luck.

Added: And watch the Thorite and other waterplug products, they can chemically burn as they dry. You'll need gloves of some sort, and they are very very abrasive.