bks wrote:
I am looking to add insulation to a first room floor (100-year-old
farmhouse, full fieldstone basement underneath). Will be removing
carpert and pad (about an 1"), putting down laminate flooring, so
have some room for a layer of insulation.a

Is it possible to put a layer of foam board below a 1/4" layer of ply
prior to flooring? The basement is a rat's nest of wires and pipes.
Maybe even a simple layer of poly would make a huge difference?

FYI: I have already done the walls and sealed all cracked in them and
around pipes. New windows, etc. This is the last frontier.

Thanks.

No, go the proper way and insulate from underneath.

I have one caution however. You say you have pipes in the basement.
Assuming some of those pipes carry water, I suggest that you make sure you
don't insulate so much as to allow some parts of your basement to go below
freezing on the coldest of days anywhere near any of those pipes.

--
Joseph Meehan

Dia duit