CSI with waterline tiles

[ka8yiu]

Having a fiberglass pool, I have always followed advice I got here that a negative CSI, down as low as -.6, was OK. But, I actually have waterline tiles, and was wondering if I should be maintaining a higher CSI to avoid the grout from being damaged. Thoughts?

Kevin

 

[mknauss]

If the grout is cement based, yes.

It is far better to use silicone grout for tile on a fiberglass pool.

 

[ka8yiu]

The tiles were in place when I bought the house. I’m pretty sure they’re cement based. Do you think a silicone grout and spreading a layer over the grout lines could help to waterproof and protect them so leaching is not a problem?

 

[mknauss]

I would not do that. The grout hopefully was epoxy based when applied. Do you get cracking or water wicking up the grout lines leaving calcium scale or algae, above the water line?

 

[ka8yiu]

I would not do that. The grout hopefully was epoxy based when applied. Do you get cracking or water wicking up the grout lines leaving calcium scale or algae, above the water line?

I do not get any scaling, but occasionally one of the small lower tiles comes free and I have to reattach and re-grout it.

I can’t say I’ve noticed any water wicking, but occasionally I get a little tinge of green right along the waterline in a very small spot. Quick little brushing takes care of it.