During a hurricane
or other wind event, one of the most devastating types of damage that
can occur to a structure is the loss of its roof. Once the wind is
under the roof, further structural damage can occur, and water intrusion
can ruin both the structure and its contents.
Past solutions have
focused on providing means of mechanically holding the edges of the
roofing material to the roof, or by mechanically reinforcing the
attachment between the roof structure and its supporting elements by
means of various clips or braces. The WindTripper* does hold down the
edges of the roof and roofing material by mechanical means. More
important, the Wind Tripper addresses the root cause of the problem by
disturbing the lifting force of the wind on both the roofing material
and on the roof itself.
The roof of a building is a large lifting surface, similar to an
airplane wing. Wind reaching a building must flow further to go over
the building than along the surface of the earth. Therefore, the wind
accelerates and creates a low-pressure area over the roof. The wind
tends to lift the roof and roofing material both by shear catching the
edge of the roof or roofing material, particularly along the bottom and
sides, and by the low-pressure area over the roof tending to lift the
entire roof structure off the supporting frame. Once the camel's nose
is under the tent, the rest of the roof is vulnerable, as we have seen
in countless news videos of roofs departing structures and of post-storm
The WindTripper* is an aerodynamic device that attaches to the edges of
the roof. In its stowed position, it is simply an extension of the roof
edge with the spoiler resting against the fascia. However, as wind
speed increases, the spoiler rotates to its deployed position.
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The overhang surface then rests on the edge of the roofing material.
The harder the wind blows, the more firmly the surface presses down on
the edge of the roof, preventing the wind from lifting it off the
sub-roof. In its deployed position, the spoiler surface rotates to
extend into the airflow over the roof, disturbing the airflow and
limiting the ability of the wind to lift the roof off the supporting
walls. The spoiler is shaped to disturb the airflow over the roof.
Again, the harder the wind blows, the greater the effect.
When the wind speed
decreases, the spoiler returns to its stowed position. Wind approaching
from the roof side of the spoiler merely holds the spoiler in its stowed
If a gutter is
installed, the spoiler nests against the inside of the gutter. The
overhanging surface extends over the gutter. Rainwater runs into the
gutter through the gap between the roof drip edge and the WindTripper*,
while leaves and other debris runs over the overhanging surface and fall
clear of the gutter.
fast and easy. Wind Tripper sections are simply attached to the fascia
with the supplied hinges. The greatest strength is achieved if the
hinges are spaced to attach to the ends of the rafters of the roof
structure. If a gutter is installed, notches are cut so the spoiler
surface clears the gutter supports.
Once installed, the
WindTripper* appears to be a natural part of the roof edge. The spoiler
deploys only when the wind speed is sufficient to rotate it, and stows
automatically when the wind speed drops.
The fixed version
of this device simply attaches to the roof edges with clips designed to
hold roofing material to the sub-roof.