One of the hardest things to get right is the fire stopping on your new bathroom renovation project. I've seen all sorts of crazy things done but the best approach is to talk to the pros. For me here in Vancouver that's the folks down at Hilti. The Hilti boys have page after page of options and they cover all types of setups. There is no one step maneuver and often it is not so easy to fire stop a job properly.
On this renovation we are fire stopping the trough hole from the bath tub location. It was a large hole and much bigger than ones I've done in the past. I went down to Hilti and discussed the job at hand and left with some fireproof chalking and mineral wool.
The spec sheet requires a 4" layer of mineral wool and a 1/2" of fire stopping chaulking.
Here is how we installed it.
I have never failed a fire blocking (stopping) inspection in Vancouver and owe a huge thank you to the staff at Hilti for being so patent with me and all my questions.
The ceiling of the next apartment. Notice how the waste line is copper. With high rise work the piping needs to be copper or cast through the hole. Once outside this through hole and above the PTrap the code is less strict. The plumber rigged this set up for a new free standing tub.
The mineral wool from hilt is nice to work with but itchy. It comes with dovetail joints and it's required to use 4". I used an extra layer and cross hatched the pieces going in.
Three tubes would have given me about 10% more product than necessary but to be safe I used a whole extra tube to ensure the coverage was correct everywhere.