I own an old 2 family home. While in the basement, I noticed that Some of the interior walls have no 2x4 plate at the bottom of the wall, so there is basically an open space between the basement, through the 1st and 2nd floor to the attic. The same situation occurs in many of the outside walls.
How should I "firestop" this space? (I was considering wood blocking nailed, and sealed with fire rated caulk.)
Also, do you know of a website with residential firestopping/proofing basics? (I have done some searching but everything is either too technical, geared toward commercial construction, or just too wordy. Thanks.)