How far is the span of the existing joists, Andy? Not the o.c. dimensions
but rather how long are the joists? If all you do is add additional
joists, they will require the same support as the existing ones. If they're
not supported over a long span (and keep in mind I'm not a structural
engineer) all you will do is weight down the areas between the existing
supporting ones when you screw down the floor to them. It sounds like it
might be an untaking for you - but to protect what you've got from any
future complications - I believe I'd make the investment. 48" O.C. sure is
a long span for floor support below a living area.

Jim



"Andy Francke" wrote in message:

Thanks.

This is what I was wondering - whether retrofitting in more joists is
generally possible (obviously whether it is specifically possible in my
case
is ultimately the question, though as I'm sure some will point out,
somebody
with experience will need to make that determination - I just wanted to
know
if such a thing were advisable/doable before calling around about it).

I guess the key question is whether those joists are going to need extra
piers or not - the crawlspace is filled with footings on top of which
posts
are placed, supporting the joists above. Adding more of these, I gather
would be the most difficult aspect of all this.

Andy