On 20 Jan 2006 04:40:50 -0800, "nhurst" wrote:

Is it OK to bury AC ductwork in a crawlspace? I need to do some repairs
on my ducts because my crawlspace is very narrow (maybe 18-20 inches
from dirt to joist in most areas), and the ducts have been beaten up
over the years by people scraping over them to get from one place to
another.

I was thinking that if, when I replaced the damaged duct, I made a
trench in the dirt, lined it with 18mil Visqueen, and put a piece of
plywood on top of that, I could both open the crawlspace up some, and
lessen the chances of the ducting getting clobbered again.

Has anyone here done such a thing, or am I about to undertake a task
fraught with danger and unnecessary expense?


When I lived in Tulsa, it was a common practice at that time to put
the ducts underground, however they were encased in concrete below a
slab. The ducts were set and poured in when the curbwall was put in
place and then a slab was poured over them. Good point is good
insulation. Bad thing is that occaisonally a water supply pipe would
break and invariably the water would permeate and collect in the duct.
You would find out when the humidity went way up in the house.

I think it would work if you can keep the water out.