How Not To
 |
How
not
to
weave
a composition
shingle
valley |
The
keyways
between
the
shingles
are
at right
angles
to the
flow
of water
and
trap
debris.
Note
lifted
shingle
tabs
and
debris
accumulation.
(See A
well-woven
valley). |
How
not
to weave
a composition
shingle
valley |
