In my next house, I will have a masonry wood burning fireplace in my living room. It will be near the middle of my house, far from an exterior wall. My only concern is how to properly insulate it as it pokes a hole through my attic insulation. It will have about ten feet of rise through my attic, so I was wondering how I could best insulate it. It will be directly exposed to the outside on top, so I need a way to slow the heat from flowing up and down.

I had considered making the chimney out of cinder blocks with a inner tile liner, and filling the first 8' worth of cinder block cavities with fiberglass, and then wrap the outside of the blocks with fiberglass. This might help some, but I will still have that direct masonry bridge from top to bottom. Any ideas?

Insulating around a chimney is not an easy task. I went to great lengths to try and insulate my chimney chase with only so-so results.

Most prefab fireplaces use a dual pipe chimney that relies on air moving between the flue pipes to keep them cool. Problem is that if air is moving between the pipes, it is exiting your house. Some manufacturers offer a cold weather cover that connects to an outside vent to reduce this problem. This is an external vent in addition to your combustion air vent. So outside air is used to keep the pipes cool. In theory, you could use this setup and heavily insulate the chimney chase and be OK.

Other manufactures offer flue pipes meant for northern climates that are metal pipes with insulation packed between. This type of system is more expensive, but, it does not rely on any air movement. I believe you could build a more efficient house using this type of chimney setup, but I am not sure about the costs.

The best thing you can do to make your wood stove more efficient is have a roof-top damper.

Thanks for the heads up on the rooftop damper. Does anyone know if you can use two dampers? My dad has an interior corkscrew style damper that I like, and I just wonder if I could use both.

I had considered using one of those insulated stainless flue pipes, but I would still need some structure to support my chimney and load bearing ridge beam. I could use a fake chimney, wrapped in Z-brick or something similar, but I still need to stabilize my load bearing ridge somehow. Masonry just seems to do the job so well....

When it comes to upgrading your insulation, you can choose from a number of different materials. Each material has different insulating qualities as well as installation requirements, so you'll want to consult your contractor about which is best for your home and your needs. Popular options include spray foam, blown, and batt insulation.

Everything fine with your ideas. Maybe you can think about an bioalcohol fireplace. It needs no chimney and if used in ICF homes with high heat resistence it is a good extra for a quick heatup. Bioalcohol (96% Ethanol or better) burns with no toxic waste but should be of high quality. We have several users that are really happy with that solution.  Attched a few pictures. If you goo with a complete chimney open fire place you should think about fire bricks and a glas version to not have a heatloss ( Thermal bridge)  through your chimney.