In article JQ62g.936717$xm3.550691@attbi_s21,
"Dave Lyon" wrote:

Ya, but I'm not sure what kind of insulation would hold up to a full time
machine shop. The insulation that is there, is a 4' wide roll with a green
sort of plastic facing the inside of the shop. The plastic is starting to
get holes and stuff in it from the years of abuse.

I've seen shops where they have sprayed insulation on the inside of the
walls. After a year or two, the walls are black with carbon dust and chips
that can't be effectively cleaned.

I guess I have seen exposed fire-retardant cellulose sprayed on things,
but would consider it a poor choice for a shop. Generally there needs to
be an inside wall covering (often more sheet steel in steel buildings,
or drywall) to keep the insulation from direct fire exposure, reduce
physical abuse, and make cleaning possible. Some types of ceiling
insulation (generally not foams) are OK to leave the inside face
exposed, but it's never a good idea on walls, as you have seen.

I'm just looking for a quick and easy solution

Cheap, fast, good pick (no more than) two? One product which can work,
but is not cheap, is a spray-on exterior polyurethane foam roof -
especially good if your present roof leaks, as it gets you insulation
and a new weather surface. I don't recall seeing that suggested for
walls, and doubt it would be. White steel panels spaced in 4-6 inches
from your present walls and fill behind with insulation of choice
(whatever's cheap) would be the best wall solution I can think of that's
durable and cleanable.

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