Creaky americast tub.

[cat lady]

It was not set in mortar. Tiling around tub is done, including floor. A friend wants to try to extrude foam under the tub through drain. Any thoughts? Any better ideas? Thanks!

 

[Reach4]

I feel confident that the friend did not mean through the drain, but somehow to inject foam from below near the drain.

What is your access to the space under the tub? If you could shove plastic baggies with cement blobs under the tub, that would seem to be better than foam. However foams vary. Anyway, is the tub over a basement or crawl space? I am not a plumber.