Ripping out a chimney sounds exhausting! Can you not do that so that I don't feel tired?
Now, if you get rid of the brick, wouldn't you have a higher R-value once you fix the house?
What would you do with the brick? I vote for a fire pit or pizza oven!
I have watched many videos by this Canadian.
He reused as many boards as possible, while there were many commenters saying "I do this for a living. You should have ripped out everything and started over!"
I believe that it was here he said to not use composite decking, it is hotter than wood, so you need to wear shoes when you are relaxing on your deck:
A quick search says that heat retention is proportional to the density and composite is denser than normal wood.