High Density Foam for Tub Installation

I have decided to use a pro to install our whirlpool tub in our bathroom remodel. This morning I did a walkthrough with the plumber of the installation. It is a Kohler whirlpool tub (6' Miraposa drop-in). He said that he usually uses high density foam under the tub rather than mortar. He said that all that is needed is support under the tub to prevent it from flexing and that mortar will not hold it in place any better.

Based on the Kohler instructions they do not mention foam as an installation alternative. Is this a proper installation method?

Thanks, Mike

foam

It is what I use most of the time. Just make sure it does not lift the tub as it expands.

HJ - Thanks for the response. I was going to pick it up for the plumber to save him a trip. He said it was the stuff that comes in the cans. Is this the same foam as the Great Stuff used for window & door insulation?

Mike

Don't think you want to use the "window and door" foam, it stays soft and will not give any support.

Paul

PEW

Would the gap and crack filler be the product to use or is there somehting else I should be looking for?

Mike