Intent 1:
To limit the probability of water running back under
window sills or down the face of masonry, which could lead to water
ingress.
This is to limit the probability of:
- the deterioration of masonry due to freeze-thaw stresses,
which could lead to masonry falling, or
- the deterioration of elements inboard of the masonry,
which could lead to compromised structural integrity, which could
lead to structural collapse.
This is to limit the probability of harm to persons.