Sounds to me like you are getting a replacement pool and you are wondering which will last longest. You can't just rebuild a wood walled pool with steel or polymer walls instead. There must be a support structure behind them. That means digging, replumbing, reforming the hopper and floor and everything else. Thats a new pool, IMHO.

Polymer has not been around long enough to say from past history but the stuff is strong and doesn't seem to weaken or rot under pool usage conditions.

Stainless will almost always outlast galvanized but costs substantially more. Bear in mind that not all stainless is the same. It comes in different grades. The same is true for galvanized.

Asking liner techs? Ask builders.

PoolguyNJ

Thanks. I realize that it is a new pool really. I have been in touch with a couple of builders--that's what brings up my question. I think you answered it. Polymers haven't been around in wide use long enough to see how they last (although they sound like they should be a great choice). I understand that they don't weaken or rot, but I have heard they get more brittle, and have had one liner installer tell me he's seen cracks.

And I understand that galvanized steel rusts, but does it rust so it just doesn't look pretty, and may need sanding and foam during liner replacement, or does it rust to failure? In other words, are polymer and stainless just an upsale for something that isn't really necessary?

BTW, I am in central Jersey and have very sandy (but iron rich) well drained soil.

Thanks again

Not all polymers are equal just as not all steel is equal.

If using polymer panels, I would expect 1/8" gravel as a backfill material to be about the best there is. It neither swells nor compacts ensuring the walls won't bow out. The gravel stays put and has less tendency than sand to "flow" towards new voids.

Can polymer walls crack? Yes but not from aging, but rather from some poor construction practice. If you take away it's support, as underground erosion can do with sand, eventually it will crack and a steel wall will bend.

Which is better?

If better is less expensive, then galvanized steel will win.
If better is longest lasting, I think polymer will win.

Choose your builder wisely.

Scott

dingosurf-If you search my user name, john1953, in the search box, you will find my posting "Do It Yourself Poolbuild" with pictures showing my family constructing a polymer pool. You should be able to see pictures of the walls and some of the construction steps. I was very happy with how the panels were built and the strength of the pool. While this was a major job for me, an Iowa schoolteacher, it was a worthwhile project. If you have any questions just let me know.