The last area to be floored in is the "Safe Room" This is across the main duct running above the center of the house. You can see it in my drawing and it will show up in some of the images.
The room is being built purposely for my guns, ammo, and probably general military gear since it ended up so big. The room will be hidden and not appear to exist for anyone who is hanging out having a beer or watching the game in the main part of the cave. I will hang something over the wall to the entrance and it won't be shown to folks that I would have any reason to not trust. It will be sealed up with fire rated sheet rock and fire rated paint.
The room was going to be like 8' x 8', because, you know, who needs a gun safe larger than 8' square? Right? That's a pretty big increase over your largest safe down at the store that's what maybe 24"x24" or something? That went out the window due to where the walls below fell. I had to go 14' out to hit another wall and even then, both ends actually sit on doubled up 2x12s that span some open walkways in the house below as you would think of a laminated beam doing. So at any rate, what I ended up with is a 8' by 14' gun safe.
All the OSB pictured throughout is one of my freebies. I was riding around checking out scrap piles at new construction sites and this guy had 10 sheets of 5/8 foil backed that he didn't need but had seen some rain so he couldn't return it. Definitely a major savings. I also have a large amount of 2x4s and other dimensional lumber that is getting ready to go into walls.