Civil Engineering Reference
In-Depth Information
Figure G6-1
Sketch of process result-
ing in unbalanced gable
roof loading with the
wind blowing from left
to right.
for gable roof drifts is similar to that for leeward roof step drifts. That is,
given the same wind and snow source areas, the volume of snow in a gable
roof drift will be similar to that for a leeward roof step. As Chapter 7 of this
guide will discuss in more detail, the cross-sectional area of a leeward roof
step drift with drift height
h
d
is
Area
=
½(base
×
height)
=
½(4
h
d
)(
h
d
)
=
2
h
d
2
For a gable with a 1-on-
S
roof slope, the triangular drift surcharge
with
the same area as th
e ste
p drift surcharge has a horizontal extent of 2
h
d
S
and a height of 2
h
d
/
S
. The top surface of the gable roof drift is taken as
nominally fl at.
Figure G6-2
Gable roof drift with the
wind blowing from right
to left.
