Insulating exterior masonry wall for insert - best way to proceed

[joefrompa]

Hi all,

Tomorrow's the day!

Getting my Lopi Republic 1750 insert installed by a local chimneysweep company, including an insulated liner. Instead of buying my own fire batts/ceramic wool, I thought I'd ask them if they have any extra that we can shove around the insert.

The chimneysweep person on the phone (NOT the installer, just someone who has been there a long time) thought this made alot of sense but hadn't heard of it before, and said they would ask the installer if he had extra rockwool/etc suitable for this. She said she's heard of people having iron shields but as I pointed out to her, that would help but the insulation would act more to "hold in" the heat.

Anyway, I wanted to run this by the group: If I can just "shove" excess rockwool around the back and sides of the insert, is that a pretty good way to proceed?

Joe

 

[midwestcoast]

Nope. You can insulate the masonry, but you don't want insulation in contact with the insert. You want an airspace around it. If you only have batt type insulation you'll need a way to attach it to the FP walls. Sheet metal cut to shape, placed over the batts & Tapconned into the mortar joints works. Sheet metal also will reflect radiant heat back at the insert. Stiff insulation can be just attached to the FP walls.

 

[midwestcoast]

More important is a sealed & insulated block-off plate