Sealing fireplace insert surround plate

Hello,

I have a Timberline insert and I'm wondering if there is a better way to seal between the surround plates and the bricks other than fiberglass. I'm going to be installing a steel flu liner this weekend and the fiberglass has never sealed well and you can see the insulation from the sides which doesn't look so nice (not so much in the attached photo but you get the idea). I'd thought maybe there were other options out there; I picked up some RTV but after looking at it again, maybe the gap will be too much for the RTV.

I appreciate any opinions and advice!

thanks in advance,
Steve

A seal between the panels and the brick won't be necessary after the liner is installed. You can seal the chimney at the top, around the liner with insulation. Or, with a block off plate at the bottom. Or, both. Do a search on here to find out how to go about it.

Excellent - I was actually hoping that would be the case but I wasn't sure. I got an insulation wrap for the flu liner so there really shouldn't be much room left for air infiltration once the flu liner is in. Too easy - thanks much!