Intent 1:
To limit the probability that:
- contact with flue gases will lead to corrosive damage
to mortar, or
- flue gas condensate will leak from joints in chimney
liners, which could lead to corrosion or freeze-thaw damage to surrounding
masonry.
This is to limit the probability of
the escape of heat or flames, which could lead to the ignition of
combustible building components, which could lead to damage to the
building.