General provisions
Closed and open fireplaces

There are two main types of chimney:

• American chimney (figure 5 ): the flue runs directly from the fireplace. A satisfactory draught is ensured thanks to a shelf (or anti-backflow platform) and the avaloire, or smoke chamber, which are indispensable elements ;

• elevation chimney, preferable to the previous one (figure 6 ): the flue rises directly from the foundation, behind or beside the fireplace to which it is connected by a masonry flue.