Sealing Flagstone

[tone100]

I'm thinking about sealing my Oklahoma flagstone. I read that I need to pressure wash it first and do it first thing in the morning when its cool outside. I was going to use the 511 sealer from home depot unless someone has a better suggestion. I'll be converting to salt soon and want to do this first.

Also there is a small hairline crack in the mortar on my flagstone spillway from my hot tub. Can I just use sanded caulk to seal this? On the back of my pool I have a moss rock weeping wall. I guess I should seal this too. My only concern is the bottom level always sits in the water and I'd have to drain some water out in order to apply the sealer and then leave it drained for a day for it to dry. I'm worried this will cause a ring on the white plaster.

 

[tone100]

Any help would be appreciated.

 

[Poolsean]

You would need to check with the experts on which sealer to use, but properly sealing the flagstone will help with any degradation issues. I wouldn't worry about the flagstone below the water line. Its not likely to see additional degradation due to the salt water. Just the flagstone above the water line that is prone to splashing water may experience the effects of the "freeze/thaw cycle" and the expansion of the salt when dehydrated.
Regarding the crack, if the sanded caulk is water and chemical resistant, then it should be fine to use.
On the moss rock weeping wall, do you have pool water running down there too? If not, there's no need to seal it. You mentioned the bottom sitting in water. I'm not picturing this, especially on the back of your pool.
Can you attach photos? We'd love to see your pool too.

 

[tone100]

Here is a photo of the weeping wall on the back of the pool. The water comes out just above the waterline in 4 spots. Since its moss rock and not flagstone I might not even need to worry about it. I've never seen any flaking there just a little on the flagstone coping. Thanks again.