On Wed, 29 Jun 2005 01:39:05 GMT, "George E. Cawthon"
wrote:

Not a must, maybe not even common. Many interior
door tops and/or bottom are raw wood. Most of
the bottoms of old time solid doors that I have
seen do not have paint on them. There is stain
but no finish on the top or bottom of the hollow
core doors in my 1970's built house.

My guess is that's because the painters didn't really care, as many
don't today.
I've been hanging doors for too many years now and every warranty
sheet or sticker that I've read requires finish on all 6 sides or the
manufacturer's warranty is void. Of course the warranties are
normally only good for one year anyway.

Mike O.