Help: Which Roxul to get for insulating behind block-off plate?

[edge-of-the-woods]

Hi all, there are a lot of threads on this, but I see a lot of conflicting information. Would really appreciate some advice, or confirmation here.

I'm about to install a block-off plate, using info from this thread:
https://www.hearth.com/talk/threads/poor-mans-block-off-plate-ii.73018/

I just want to clarify that this product is appropriate for this purpose:
http://www.homedepot.com/p/Roxul-Sa...e-Wool-Insulation-12-Roll-RXSS31525/202531875

A lot of threads just say "Roxul", but it is sold in batts and in bales (which I assume is like pink fiberglass insulation/cotton candy). Since some block-off plate threads talk about "stuffing" the cavity around the liner with Roxul, I was assuming this meant the soft stuff, as shown below. However, other threads say things like, "Use the ComfortBatt" type, which looks more like a sheet.

Is this Roxul below what is recommended? I don't mean to be rude but I am not looking for speculation or hearsay or opinions. I would appreciate hearing from people who have actually done this before.

 

[Core]

When I did my block off plate for my insert I used the Roxul in batts like in your picture. It was in four foot lengths about 5-6 inches thick that I was able to cut to appropriate lengths while using a dust mask and long sleeves. Some advise to stuff around fire box but I think that is a bad idea. I'm not a Roxul expert so read label carefully to make sure the Roxul doesnt have different temp ratings etc. My lowes only had one style.

 

[cableman]

I used safe and sound cause i had it laying around. You can use the r-value batts also

 

[browneyesvictim]

I just did this a month ago. I had the same conundrum as you and I used the R15 Comfort batts. Home Depot had both. Oddly enough, I had talked with a local installer that I had bought my 6" liner from about whether they installed block off plates and insulation in their installs. He said they just stuff fiberglass insulation above the smoke shelf to seal it off and no block off plate. He insisted it was not necessary to use the expensive rockwool insulation and that fiberglass was just fine. This was a professional installer now telling me this...

 

[NoGoodAtScreenNames]

I used the safe and sound for mine. I think they don't market it as an insulator it's a sound blocker. It didn't say the r value but a few layers of it has to have some. They are both fire proof to a high temperature - make sure that's the case for whatever you buy.

 

[2broke2ride]

I just did this a month ago. I had the same conundrum as you and I used the R15 Comfort batts. Home Depot had both. Oddly enough, I had talked with a local installer that I had bought my 6" liner from about whether they installed block off plates and insulation in their installs. He said they just stuff fiberglass insulation above the smoke shelf to seal it off and no block off plate. He insisted it was not necessary to use the expensive rockwool insulation and that fiberglass was just fine. This was a professional installer now telling me this...

I had a thread about this, I had a local certified sweep that I know ( good customer at my shop) tell me to do the same thing.

 

[edge-of-the-woods]

Thanks folks! I feel reassured. Feel much better about packing the chimney full of stuff now. Going to get the Safe n' Sound from Home Depot this afternoon. It's a lifetime supply, but only $42.00.