I want to add a wall covering on top of my 5/8" type-x drywall in my attached garage in Minnesota. What limitations do I have other than not to use flammable/vinyl/plastic material?

What materials would anyone recommend?

  • 3
    Your question isn't entirely clear. Are you asking specifically about the firewall? Why do you want to cover it? What goal are you trying to achieve? – isherwood Oct 7 '19 at 18:37
  • I second @isherwood's call for more details - also where in the world are you in some places that may violate code. – J Crosby Oct 7 '19 at 19:46
  • What sort of finish are you trying to achieve? – ThreePhaseEel Mar 6 '20 at 2:05
  • Did you ever get this resolved? If so, please give a check-mark to the answer that helped you the most, or write up your own answer explaining what you did to get it fixed and give yourself a check mark. That will help others with this kind of problem know that this has a resolution and is a good place to look for their answer. – FreeMan Aug 3 '20 at 12:14
  • Sheet metal would be good in an old-school highly effective manner. ;-) – Ecnerwal Dec 1 '20 at 3:08

The Code does not restrict material installed on top of “Fire wall” materials. (Btw, the 5/8” type-x gypsum board is only required on the garage side. It’s not required on the “living space” side.)

Also, you can have “holes” in the gypsum board, including electrical outlets, electrical switches, a door if it’s fire rated, etc.

Also, the garage cannot have a door opening directly into a sleeping space.


Oops...actually the Code does restrict what can be installed on walls and ceilings. They can’t have a “Flame Spread Rating” greater than 200, unless it’s less than 1/28” thick and cemented to the surface and has a flame spread rating less than paper. (See ICC R302.9). Also, they can’t have a “Smoke Development Index” greater than 450. (See ICC R302.10)


It is a "fire wall" only in that the requirement for 5/8" drywall is there so that if a fire starts in the garage, it will take 60 minutes before it burns through that thicker drywall and gets into the rest of the house (as opposed to 30 minutes for standard 1/2" drywall). What is on that wall in the garage is totally irrelevant to that issue, so you can cover it with napalm if you are so inclined (actually you cannot, but I was exaggerating to make the point).

  • Actually it does matter what is put on the gypsum board. See my revised answer and ICC R302.9 and R302.10. Also, 1/2” gypsum board is allowed on the wall between the garage and house, but 5/8” Type “X” is required on the ceiling if there is living space above the garage. (See ICC 406.3.4.) – Lee Sam Mar 6 '20 at 1:03

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