Waterproofing swimming pool

Does anyone know what the stuff is called that is put over the concrete in swimming pools to keep them from leaking? I’m not looking for stuff to repair a leak, but to treat the the concrete at the time of construction. Thanks.

The concrete shell is coated with some sort of plaster, tile, or a combination to form the waterproof coating. Sometimes there’s a thin bond coat under the plaster. Bond coats are generally used when new plaster is applied over older plaster but not over a new shell. Mixtures of small pebbles in plaster are also used.

I once saw a truck with the hopper and hoses used to spray building materials.
The door signage ID’d it as a Pool build/repair outfit.
The bags of “stuff” were labelled “White Concrete”. Never heard of it before and not since, but I was not hallucinating at the time (ah, fond memories…).

Generally, they are called “Plaster-Lined” pools

There are several swimming pool forums - Google “swimming pool forum” - add the “swimming” unless you enjoy billiards.

Gunnite (or Gunite) is a popular product for this use.

Sealant?

Yes - this is the stuff. Someone told me about it and I could not remember the name. Thanks.