Insulation for shop: cellulose or foam?

[Wild Turkey]

What has the brain trust's experience been with either one?  I've been assuming foam but contractor offers both and I'm looking for experience.

The roof will be foam, but the walls could be either.  Would I need to cover all the cellulose to hold down dust problems?

My experience with glue-in-place-cellulose has been that it constantly sheds so it would need to be covered.

Anyone used either/or?

[cndamm]

Closed cell foam is the best insulator but isn't cheap. Moisture reduces the R value of most insulations but not closed cell foam.

[daddo]

You're not going to cover the walls?

I wouldn't want foam exposed at all! If I did foam, it would only be a safe foam like Icynene. It doesn't gas off chemicals where you need a respirator or vent and clean the space for 24 hrs.

Cellulose may not burn but it has been known to smolder, but usually puts itself out. (I experimented with it). It's better than the rest fiber types to stop infiltration.

I would consider foil back or vinyl back fiberglass batting on exposed walls.

If you're going to cover the walls, then Icynene foam is the best, but you'll never run a new wire in the wall. Cellulose won't be a dust problem. Batting does a fine job.

[BloomingtonMike]

Icynene guys here are idiots. They push .5lb open cell for more money than 2lb closed cell. You better ask actual product questions if you have them out. They will try and fill you with stories about what they have done for customers vs what their product really is. Ymmv.

[fredhargis]

You aren't considering fiberglass?

[Stwood_]

Have the walls netted and used blown fiberglass.
I would do the attic with fiber also, after you put a ceiling in.

[paulmaine]

I used Dow Thermax for my basement insulation. It was called 11177-PL-300 Foam Board Adhesive-2902.  This was the only foamboard that did not require 15 minute thermal barriers; in Maine it was certified as equivalent through the state Fire Marshalls office.  Two inch Thermax has a  R 13 value.  Both sides have thick aluminum cover.  Each piece cost me $53 but it did not require gypsum board.  I had to special order it here in lots of 20 pieces of 4x8 sheets. You can find out info from a Dow website;  Dow was very helpful. Thermax's shiny finish brightens the shop.  I used double thickness(giving R26) above and just below the ground , single thickness down deeper-the bottom four feet for me. 

    You can find out what other folks in your area by calling the local town building inspector.   

Paul from the beautiful coast of Maine.