Big_Jake wrote:

The
mechanic says "I haven't seen it done."

Most mechanics can't even work on cars, don't ask them about your
heating system.


The problem is it was the HVAC mechanic, with many years experience and
working for a moderately large contractor, who said it. I know ceiling
runs can be done but don't know what the trade-offs are, particularly
with mixed ceiling and floor. IMHO the comment raised questions about
the mechanic. And unfortunately not the only thing that raised questions
about the mechanic. (It isn't my house. I'm looking for advice for the
owner.)

Thanks for the replies.

--
bud--