Insulation advice needed

[michigan123]

Looking for some expert advice here. A couple weeks ago I started noticing CO readings from my detectors around my insert (quad 5100, full insulated liner, block off plate). I traced the CO to the stove and found that it was coming from the air intake on the front of the stove when the fire was burned down to just coals and the air controls were opened all the way up. Long story short, I decided to install an O.A.K. to assure myself that in the case of backdrafting it would just send the CO outside instead of into the house. With my stove a passive OAK is required so I knocked a couple bricks out, installed the OAK and now I'm having trouble finding a way to seal around the front of the stove to the fireplace. I tried some Roxul AFB insulation that was supposed to be rated up to 2000+ degrees but that has been discoloring and smelling really bad when my stove really gets hot. Aparently it shouldn't be subjected to high heat for a long period of time. I need to know what kind of insulation to use to seal around my insert right behind the surround that is going to be safe for these high temps. Would that Kaowool work? Is that stuff safe from nasty odors or breakdown at high temps for long periods of time? Thanks in advance for any advice here.

 

[Dune]

Kaowool has no smell that I have ever noticed, and can take direct exposure to at least 3000 degrees F.

 

[oconnor]

..... With my stove a passive OAK is required so I knocked a couple bricks out, installed the OAK and now I'm having trouble finding a way to seal around the front of the stove to the fireplace. I tried some Roxul AFB insulation that was supposed to be rated up to 2000+ degrees but that has been discoloring and smelling really bad when my stove really gets hot. Aparently it shouldn't be subjected to high heat for a long period of time. I need to know what kind of insulation to use to seal around my insert right behind the surround that is going to be safe for these high temps. Would that Kaowool work? Is that stuff safe from nasty odors or breakdown at high temps for long periods of time? Thanks in advance for any advice here.

The Roxul AFB isn't actually rated for any high temp use - it is intended as insulation in a wall, but has the benifit of delaying fire progression - in essence, it's designed for exposure to heat only once - the day the wall catches fire. Unfortunately, they do have a statement about the high melting temps that rockwool has, but that is a marketing statement - if you look at thier Spec sheets, only a few have a stated maximum sustained use temperature, and these top out around 1200*F to 1400*F. The stuff they sell at hardware stores etc for wall insulation just isn't meant for constant heat exposure, and you observations confirm that.

KAOWOOL and other ceramic fibre blankets and board type insulation would work - you should find out the exact manufacturer and download the spec sheet for the product.

Instead of sealing the surround plate or the front of the stove to the fireplace, have you considered installing a block off plate? That will help keep the flue warm, as the air around the liner won't be refreshed by room air, and it will keep room air from exiting up the flue. In addition, insulating the liner itself will help keep it hot enough to avoid the draft reversal that you are mentioning during the coaling phase of the fire, and ensure you meet code requirements as far as chimney clearances to combustibles are concerned (2 inch air gap required around a masonary flue)

Here is the block off plate link https://www.hearth.com/econtent/index.php/wiki/Special:Search_results/

 

[Rudyjr]

Brent, Do you still have a rock wool block off plate on your undersized uninsulated chimney installation that you paid to have installed?

 

[oconnor]

Yes I do - I hope you are enjoying my frustration in getting it fixed - I am not enjoying it.