The directions for my tub say either you can use mortar or construction adhesive on four points that are the bottom of the tub for this purpose.
1-I think for me it would be easier to use the adhesive. Any reason not to? And would loctite PL Premium Polyurathane construction adhesive be a good choice for adhesive?
2-How would I get the 5' tub into the 5' space without dragging the glue over the floor and off of the intended areas on the tub?
3- Is it OK to put the tub over bare plywood sub-straight. the rest of the floor will be tiled.
4- What would be the best type of insulation on the walls. 2 walls go to another room and on wall is against an inside a crawl crawl space but is considered an outside space.
5- I am planning on putting drywall up after the tub is in, then kerdi to waterproof. Do I just leave the area in back of where the tub is down to the floor bare, except for the insulation between the joists?
6-There is an area in the sub-floor that is cut away where the drain goes. It had some kind of white cotton like pieces of what must be insulation that is beteen the joists. I took some of it out because I wanted to get at the drain. Is it important to put new insulation back in the area I can reach? This is a second floor bath and I want it too be as sound proof as possible for the rooms below.
7- I also want to do the drain over-flow and the new shower/tub valve myself- and hope I can fell confident enough with all the help here to do it-but I'll leave that for another post.
Because it is not cast iron, I highly recommend the mortar base. The tub will not feel solid without it. The mortar is placed in small piles on the subfloor and the tub is set or rolled down into the mortar bed.
The Kohler instructions are pretty clear about the framing that is required around the tub. A tub is normally set on the subfloor and the floor tiles are cut to fit up to the edge of the tub.
There should be insulation in any outside walls. Most of us use what is readily available. Spray foam is the best, but not many companies would be willing to do such a small job. It would take more time to set up and clean up than it would to apply the insulation.