Negatives are the most valuable possessions I have. I store most of my negs in plastic hanging file containers from the container store. I do that for protection against water. My portfolio negs go into 1/2 hour 350 fire rated hanging file type safe. This safe and the plastic hanging file containers then go inside 2 phoenix commander fire safes ( they are either 2 or 3 hour rated, when i bought them they were listed as 3 hour, now they are listed as 2 hour). In the two safes I can store a total of 4 file safes/containers, or 6 if I remove the shelves and stack them on each other. I considered media safes but a media safe weighs twice as much for half the capacity. So I thought I would instead make the room that the safes themselves were in safer.
The room that the safes are in, my archive/storage room, is fire hardened. Two of the 4 walls are heavily steel reinforced 10" concrete, the floor is ground level and also concrete. The ceiling, concrete walls and other two interior walls are doubled layers of 5/8" fire rated (x type) gypsum board for a total on the 1 1/4" on the outside of the interior walls and 5/8" on the inside interior walls. I made the outside of the wall double thickness with the fire-rated gypsum and the inside only one thickness because there is very little cause for fire initiation in the room. The biggest fire threat comes from outside the archive room. The roof above is double thickness of flame sealed roofing membrane, the roof pitched to remove water, and on top of that is an Ipe deck, Ipe being one of the few fire rated woods and a wood so hard that nails can not be driven into it.
The doors leading into the archive and my attached darkroom are fire doors. They also have silicone gaskets that prevent smoke and fire (i guess) from spreading. They also make the rooms light and air tight. To allow ventilation, above each door is a vent allowing air flow between each room and allowing the Air conditioning free movement. These vents are also fire rated vents and should the temp rise above 150 degrees F, a lead pin will melt causing a spring loaded steel door to seal the vents. There is a central station fire and alarm system that also has water sensors to alert us and the alarm company should there be a water leak that would endanger the archive room.
The prints are replaceable, granted it would take me quite a while to replace them, but they are stored in Light Impressions type boxes in large cabinets in the archive room. My gear is also kept in the archive room, in several large safes.
Here is a link for the fire safes:
http://www.kcsafe.com/Fire_Commander.html