Sir Topham Hatt wrote:
Hi,
should a shoe molding be nailed to the baseboard or to the hardwood floor?


Always nail to the base board. Unless the wall is a masonry product.

When you nail shoe moulding to the flooring across the grain, ie.
across the end of the floor boards, expansion of the floor boards will
do crazy things to the joint between the base and the shoe moulding.
I've seen a floor move enough to pull the nails upwards 1/4" at the
ends of the shoe.

If humidity in your area doesn't fluctuate, then you may get away with
it. Kentucky has humidity issues. Arizona may not. I have no idea where
you are. I'd say it's a judgement call for you to make, then live with
it.

Tom in KY, where the humidity rises and falls daily, thanks to the rain
and the temps dropping like a stone at night.