Liner insulation-not enough room?

[kd460]

Getting close to the install on my wood burning insert into an existing zero clearance firebox. I will be using a 316ti flex liner from top to bottom. I understand the significance of insulating the chimney liner.

My concern is this: The liner is 6 inch ID, which means 6 1/4 inch od. The existing zero clearance flu pip[e (double walled) is 8 inch ID and it is a straight run of about 15 ft. Will I have enough room to put the insulation and the wire mesh that holds it into place on the liner pipe and then get it down the 8 inch flue? Sounds like I need to go pretty thin on the insulation.

Would I be better off to insulate the chimney chase? It is basically a wooden chase with vinyl siding on an outside wall. Yes I would have to remove the siding, and yes I would have to remove the OSB, but, that does not bother me to much.

The current fireplace draws fairly well, I live in Michigan, so it does get cold. Thanks, KD

 

[MountainStoveGuy]

Both would be a good idea. If you dont have any offstets and a clean flue (see elks post) the pipe 1/2 inch insulation will fit. IF not, put 1/4 inch around it. If you wanted to make a super chimney system, insulate the chase too. The reason your current chimney draws well is that there is lots of heat avalible for it. That wont be the case when you get your new insert.

 

[webbie]

Getting close to the install on my wood burning insert into an existing zero clearance firebox. I will be using a 316ti flex liner from top to bottom. I understand the significance of insulating the chimney liner.

My concern is this: The liner is 6 inch ID, which means 6 1/4 inch od. The existing zero clearance flu pip[e (double walled) is 8 inch ID and it is a straight run of about 15 ft. Will I have enough room to put the insulation and the wire mesh that holds it into place on the liner pipe and then get it down the 8 inch flue? Sounds like I need to go pretty thin on the insulation.

Would I be better off to insulate the chimney chase? It is basically a wooden chase with vinyl siding on an outside wall. Yes I would have to remove the siding, and yes I would have to remove the OSB, but, that does not bother me to much.

The current fireplace draws fairly well, I live in Michigan, so it does get cold. Thanks, KD

In this case, it might even be better to insulate the chase than the pipe. The pipe is inside two relatively small layers of sheet metal and should warm up quite quickly.

Some chases are insulted up to a certain height - like 8 foot - and then a ceiling is installed into the chase.

 

[elkimmeg]

you could use pour in mix I think called theromix or thermax