Intent 1:
To limit the probability that:
- rainwater will flow across the chimney cap and into
the flue, which could lead to damage to the liner due to freeze-thaw
stresses,
- mechanical or freeze-thaw damage to the extended portion
of the liner will lead to blockage of the flue or subsequent freeze-thaw
damage to the upper courses of surrounding masonry, or
- flue gases will enter the space between the liner and
the chimney.
This is to limit the probability of
the spillage of combustion products into living space, which could
lead to negative effects on the air quality of indoor spaces, which
could lead to harm to persons.