questions about prepping the chimney for a liner

[phatdonkey]

Hey guys,

Im prepping the chimney for the liner and have some questions about the damper.

I have removed the damper plate and see that im going to have to cut the damper housing.

See the picture in this post.

The white arrow is pointing at the front of the damper housing (inside of the house side). The red arrow is pointing at the smoke shelf side of the chimney. Its hard to take pictures in the fireplace so this one is the best of 6 i took.

My questions are.

When i cut the damper housing on the smoke shelf side, should i remove a few bricks as well?

When i cut the damper on the hearth side, it looks and feels like bricks are stacked right up against the top lip of the housing. Should i remove some of those bricks too?

I am getting a 2 ply flex king pro liner with insulation. To insulate over the block off plate, should i just stuff unfaced insulation in there? Should i have the liner insulation come thru the block off plate or stay above it?

Im sure ill have more questions and will ask as i come up with them.

Thanks in advance.

Jeremy

 

[mopar440_6]

I have not had to deal with relining a fireplace so I cannot help you with questions 1 and 2. However, I can tell you that you absolutely CANNOT use standard unfaced fiberglass insulation near the chimney liner. Fiberglass insulation is combustible and once it lights off you don't want to be anywhere near it. You will need to get rock or mineral wool insulation or some other form of fire resistant insulation. Some of the other members can likely tell you if there is a specific brand name that will work well for that application.

 

[phatdonkey]

Thanks mopar. Ill probably pass on the dealer i was going to get the stove from. Those knuckleheads are the ones who told me to just stuff unfaced owens corning pink up there. Thanks again.

I have heard vermiculite thrown around. Ill research it more.

 

[begreen]

Yes, you may need to remove a couple bricks. The mineral wool insulation you want to use is Roxul, usually sold in Home Depot.

 

[phatdonkey]

Thanks Begreen. I see on the HD website that the safe and sound roxul is what i want. Looks like its safe up to 2100°F. That sound right?

 

[jkmola]

Thats the stuff. Just picked a bag up last week for my install. $55 - ish if I recall

 

[phatdonkey]

Great. Ill get it today. Im a new home owner and the wife isnt really pleased with all the stuff, tools, im buying. She will be happy with the stove though. She wants to have a fire everyday but i have explained its too inefficient and costs too much for now.

 

[phatdonkey]

Nice. Went and got the grinder and some wheels but forgot the roxul. Duh!

I cut out some of the damper housing and removed two bricks. See picture below.

I have 7.5 inches between the smoke shelf and the front of the damper housing. There are bricks right behind the housing so i didnt cut the front half. Will that be enough clearance for the liner? Doing the math it will. 6" liner plus 1/2" insulation plus mesh wrap should be about 7.25-7.5". Do i insulate the liner all the way to the stove coupler?