I am installing a Kahrs Castle & Cottage floor in a 300 sf Family room. It will be floating over Kahr's radiant heat paper and 6 mil poly and is a 9/16" thick floor. I am replacing the builder grade painted base molding with a larger base, still painted white. Should I go with a painted shoe, a Kahr's matched shoe, or no shoe - putting the base over the floor. I have seen some preference on these boards for no shoe if the base is being replaced anyway.

Threshold: The room opens to the kitchen with a 6' open doorway that is standard 4 1/2" wide. The kitchen has 3/4 Brazillian Cherry over the same subfloor. Right now there is a BC threshold that goes 3 1/4" into the doorway.

Should I:
1) Leave the BC threshold and use a Kahr's Square Nose reducer to meet it where it is?
2) Pull the BC threshold out, and cut it back so it meets the square nose reducer right in the middle of the doorway? or
3) Buy a new piece of BC 4 1/2" wide, and undercut the engineered side to go over the Kahrs and allow room for the expansion. Or something else?

I would ask about the fireplace hearth, but I have already learned to undercut the brick hearth from reading these boards!

Thanks for your opinions!
Chris

I like to see the base shoe match the baseboards. But if the new floor is prepped flat enough, you may be able to use just new base if it is wide enough to cover your expansion gap.
As far as where the new floor meets the old, flooring changes take place under a door, but since it is open, it is just a matter of taste. I would cut the existing back to the center, and use a "T" moulding to transition from the old to the new. My 2 cents worth.