First of all why do you need it

Second of all don't buy fire barrier products from Amazon, your local hardware store or electrical supplier will have correctly rated and fresh product.

If you are doing this work as a contractor, get any building inspector you've met to tell you about the products they approve for this.

Don't believe the coverage claims, it's always much lower.

https://youtu.be/2DuwMoezQLA

Also, Rockwool is a brand name of the generic mineral wool. There are other, cheaper brands of mineral wool, than rock wool and they work just as well.

I don't recommend spray foam for a number of reasons, a few being that it offgasses VOCs after installation and can obscure or make future access to repairing surfaces impossible. If, for instance, water in your bathroom seeps into your subfloor, that repair becomes suddenly infinitely more complex if you have to fight through spray foam.

I highly recommend mineral wool batts, even if you do thin ones. They can be cut with a thrift store bread knife/any serrated knife and friction fit between the joists. Very easy install for an amateur, very forgiving. Save the spray foam for those tricky gaps next to doors and windows.

We bought ours from a local contractor supply store, and it was cheaper than Orange or Blue store and they delivered for free. Not sure where you're at but search around.

As said previously, purchase locally. And also don't consider spraying this into the tailpipe of an ICE (Internal Combustion Engine) vehicle.

I have done the rim joists in my basement using a similar spray foam product. The biggest recommendations I have are:

1. Use the kind of gun pictured and not the cans that come with a straw. It is much easier to apply consistently and you can actually stop work and start again the next day using the same can. The straws work OK but they always get clogged when you stop for a bit so only use them if you are working on a small area and plan on using the whole can in one go.

2. Look into the difference between closed cell and open cell foam. I've never seen closed cell come in a can like that so I'd bet money that is open cell foam. It works great for air sealing but you need to apply a ton of it to get an appreciable R-value. Closed cell foam is a lot more expensive in the spray form and is a 2 part mixture that is more complicated to work with.

What I ended up doing was buying some 2" closed cell foam board at the local hardware store. It's relatively cheap in board form and is easy to cut. I cut a piece of the foam board to fit inside the rim joist space and then used the spray foam to air seal both the rim joists themselves and the small gap around the foam board. I think this is the most effective way to do it unless you go for the 2 part closed cell spray foam but that was more than triple the cost of the foam board + open cell spray foam.

For comparison, the 2" foam board has an R-value around 8 and, if memory serves, you would need something like 8" of open cell foam to provide that same level of insulation. You can get an equivalent R-value with 2" of the closed cell spray foam but last I checked the spray stuff was about $800 and an 8'x4' sheet of 2" foam board is around $60.

I'ved used fire rated spray foam, but not that kind. Its a messy task and I would prefer the kind that doesn't require cleaning the nozzle gun. If you don't clean it propperly I imagine it will become an expensive nightmare.

This is for sealing gaps, not doing large areas. You take a board of insulation, cut it a little smaller than the gap you put it in and then with this you seal the edges and glue it in place. It's completely different than the expanding foam you've possibly seen people spraying between joists on YouTube. This is more like a caulk gun.

Yes, 10 years ago when I bought the house and brought the internet cable inside. No problem, never had to change it. No idea what brand it was.

Are you looking for sound isolation primarily? I know lots about sound isolation.

Sprayed insulation: when you want to make future work a complete fucking nightmare. Also great for hiding damage which will be even more difficult to repair later.

Yes. Worked well but burns through cans. So overestimate for your project or look for industrial size application canisters if a larger project. No idea where. And would recommend a tyvek suit and a good face mask. Also difficult to get a desired thickness if R value is important

I'm much cheaper than that... I did 2" foam board and then those kind of cans to seal around them.

Foam board was cut into pieces roughly and inch shy of the cavity dimensions... E.g. 14*5 for a 15x6" opening. Once the foam adhesive set (e.g. following weekend) I sprayed around the edges to seal it in.

I had to get a 30" gun adapter to do it which requires cans that can be attached to a gun. The ones that can't may not have the reach to get you into the cavity.

If you have full access to the cavity, that dap kit someone else sent would be my go-to... I didn't have the immediate access or will to do it all in one go... There were unmentioned complications in my way requiring lots of prep work.

E: Code likely requires a fire block between the living space and the foam. Afaik drywall, rockwool, among others count.

Well it's a hell of an enema

You can buy it bulk way cheaper.

That's quite a lot of cans there. What are you trying to do? Thermal insulation or sound deadening?

If thermal insulation, Great Stuff is typically the default option. I would also supplement with closed cell foam insulation boards.

At a bare minimum you will need a foam cleaning solvent can to keep the gun from clogging up. Wear disposable gloves. Keep rags nearby. If you make a small mess, wait for it to dry before attempting to clean it.