This process takes roughly 2 days, compared to a week plus for a standard full masonry fireplace with chimney not using an Isokern.
We have been installing Isokern’s for almost 20 years in the Chattanooga area for Evans Lumber Company.
CORE FILLING FLUES:
You will need a Funnel for this step. As you can see, I am using a Checkers Cup which just happens to be the perfect size for the job :)
Source: http://evanslumber.biz