garage fire barrier

[pagantom]

my garage is separated from the basement (finished) by a cinder block wall that is covered with 1/2 drywall on 2x4s. it's a narrow garage, so removing the drywall and studs will provide much-welcome extra width. The only reason i can see that the 2x4 wall is there is to provide a place to install electrical junction boxes for switches and outlets. i would move the electrical to surface mounted metal conduit and junction boxes. Unless cinder block is not considered fire resistant?

 

[Yankee Chronicler]

The required separation between the garage and the dwelling unit as shown in Table R302.6 is "Not less than 1/2-inch gypsum board or equivalent applied to the garage side." It doesn't even require Type X gypsum board, just 1/2-inch gypsum board.

How old is your house? Is the wall behind the sheetrock really "cinder" block, or is it actually concrete block? Since the residential code allows for 1/2-inch gypsum board "or equivalent," you need to document that the CMU wall provides fire resistance equivalent to 1/2 inch of generic gypsum board. To do that, I would normally start looking at the equivalent fire-resistance ratings for archaic building materials in Resource A of the IEBC. Unfortunately for you, Pennsylvania didn't adopt Resource A when they adopted the IEBC, but you could still use it as a basis to request approval as an individual modification.

 

[ICE]

Perhaps you can glue the drywall to the wall.

 

[mtlogcabin]

Since 1/2" gypsum board only gives you 15 minutes of fire protection on a wood stud wall, removing it from a masonry block wall should not be a problem