Firebox / Chimney Installation - insulation proper?

[the_unnamed]

Hi Guys,

my fireplace is between my living room and my garage encapsulated between walls around the flue. Today I actually went inside of there because I had to run some wires for something else. While in there, I noticed a couple things that concerned me and I was hoping to find answers or suggestions here.

• The firebox has a big warning label that 1" of air gap must be maintained around the box. The wall studs behind the firebox are in fact a little over an inch away, so that's fine, but the faced insulation batts in between were sagging over time and actually touching the firebox. My questions here: The faced batts actually say "Fire Hazard" being 2" or so away from a firebox makes me worry. Should I replace them with unfaced rockwool batts instead or is there a better solution?
• I noticed, that only the wall behind the firebox (whichs is one of my garage walls) has insulation. The walls left and right and facing the front of the fireplace have no insulation (they are facing inside to my living room). My question here: Is there any issue with putting rock wool insulation batts between those studs as well?

Attached some pictures. Thank you in advance for any feedback.

 

[begreen]

The paper definitely should not be touching. With a little over 1" clearance, replacing them is going to be a challenge. What would be the plan.

 

[the_unnamed]

The paper definitely should not be touching. With a little over 1" clearance, replacing them is going to be a challenge. What would be the plan.

I can easily reach all batts. I started putting rockwool between the studs above, since there was no insulation whatsoever. Rockwool should be fine compared to paper face, right? This pic shows how it now looks above. Would do the save with the walls around the fire box?!

 

[begreen]

I'm more comfortable with light wire crisscrossed across the batts to secure them.

 

[the_unnamed]

I'm more comfortable with light wire crisscrossed across the batts to secure them.

I have those 16“ metal wire batt supports in there. Or do you mean something else?

Rock Wool right behind the firebox you think is ok too?

 

[KDubU]

Rock wool should be okay for what you are using it for.