Hello to all, I would very much appreciate some garage firewall code info on this:
I have a 20x20 attached 2-car garage which I built 4 years ago which has a guest room above it, the room upstairs is also attached to the house with both a 2nd floor exterior exit and a hallway to the house. No garage stairs needed. The garage level has 2 manual garage doors (metal), one rear 32" metal exit door with a window which leads to the outside, and two 32" metal doors with no windows which lead into the house on the first floor.
To rent out the guest room, I need to add a firewall of 5/8" type X sheetrock to the garage ceiling and walls. To cover all bases before I get it inspected, I have several questions. I live in NC near Asheville, but not in the city limits.
1 - Due to the guest room being above the garage, I believe I need to install the firewall sheetrock on all 4 walls in addition to the ceiling, not just the wall abutting the house. Is this correct?
2 - The garage has 9 pressure treated 6x6 posts holding up the upper floor, one in each corner, one in the center of each of the 4 walls, and one in the very center of the garage (which has a gravel floor). On the walls, these jut into the garage a few more inches than the main studwalls. Do I need to cover these "jut-outs" with vertical strips of type X sheetrock as well? The center post too?
If so, then will I also need to cover the triple-thickness 2x10 beam assembly running on the garage ceiling from front to back holding up the crosswise floor joists at their center point (extending 9 1/2 inches lower than where the main ceiling drywall will be and resting on the center post)?
3 - Around the perimeter at floor level, the lowest PT sill studs are nailed into horizontal floor-level 6x6 posts as well, which are attached with heavy "T" brackets to all the vertical 6x6 posts (which all have concrete footers below ground level). Need these ground-level sill 6x6's be covered as well (with an inch or so of concrete), so that no wood is showing?
4 - Most of the wiring in the garage is romex, and in many areas will pass through a hole in the drywall when need be, which will be sealed with joint compound. Some will be covered by the drywall at ceiling level with furring strips to create a channel space for the wiring. I assume romex is OK. There is some BX as well.
5 - In the back of the garage is a vertical 4" PVC pipe a foot from the rear wall which runs from the ceiling to underground (coming from the upstairs toilet). Do I have to fabricate a square column around this and cover it with vertical strips of type X sheetrock too?
6 - Do the metal doors leading to the house (no windows) need to be self-closing? These are the metal Stanley-type ($150 range) entry doors and are pre-hung with wood frames. Do the wood frames present a problem?
7 - The lowest couple of inches inside the garage may occasionally get moisture in a heavy rain, can I use green bathroom-type sheetrock (1/2") for this or must it be type X as well, and 5/8"?
8 - On the walls, can I mount the sheetrock sideways (8' wide, 4' vertical) or is this frowned upon. In this case, would I need to build up the lowest edge at the bottom (and topmost ceiling edge) with joint compound to make it thicker?
9 - Being in NC where the climate is decent, do I need to put insulation in the garage ceiling rafters when I install the ceiling firewall (below the upstairs guest room floor), or can I opt out on this, as it's not really a big help here?
Thanks, guys. This will be a much appreciated help if I get all this done right and get it passed on the first try.