Phil Scott wrote:


"Nehmo" wrote in message
...
Let's say you're building a 1,500 square foot house plus
garage on a
sufficiently sized lot from scratch in New Orleans after the
water has
been drained. You want to build so that the house would
suffer zero
damage should it endure a hurricane of similar size as
Katrina.

You would have to build to survive the wind, the flood
water, the
wind-caused waves in the water (In Katrina-NOLA, the wind
had subsided
before water came in; this may not be the case in the
future), and the
impacts of debris.

You need to anticipate looters and unwanted government
interference.

The house would have independent utilities, communication,
and supplies.
And the house would need a secure means of transportation
for escape if
necessary.

How should this house be built and what should it have?


Tilt up concrete walls with rebar from slab foundation...
foundation anchored with 24" diameter deep piles at each
corner.

Flat metal storm roof under the mostly decorative pitched
roof. The storm roof would be poured concrete at 10'.. actual
ceiling in the house would be at 8' or 9'.

Glass would be tempered 1/2" glass. Steel shutters outside.

Doors would be heavy metal, tight sealing that swing out, not
in.


[...]

In New Orleans, where being below sea level and inland from the Gulf of
Mexico provides a lot of protection, this would be overkill, because the
big danger was and is flooding from broken or overtopped levees, not direct
storm surge. A building that can withstand high winds isn't the real
challenge: it's the massive force of MOVING water that is the killer. The
biggest problem with flooding (other than surviving it) is the major mold
and mildew problem that will persist for months or years afterward if the
materials are at all water absorbent.

And on the coast, directly exposed to the full force of combined storm surge
and waves, it wouldn't be nearly enough, unless it really were just a small
storm shelter within a larger building, and even then there are never
guarantees. Storm surge combined with large waves can shatter even a heavy
concrete foundation if it is undercut, and the undercut is why the pilings
are there. So you would need a lot more pilings than just the four
corners, unless it were a small (e.g. one room) shelter.

The "hurricane proof house" near Pensacola is an effort to design just such
a home, but it is far from "hurricane proof". "Hurricane resistant" is a
much better description. See
http://www.domeofahome.com/news_detail.asp?ID=29 for some discussion of how
much repair the $800,000 "hurricane proof" house needed after being near
the most destructive part of Ivan. The "before" images are at
http://www.domeofahome.com/gallery/ and some design info at
http://www.domeofahome.com/DomeHome_sun-sentinel.pdf

Keep in mind that the stairs and the concrete slab that were designed to
break away become battering rams when they wash up against someone else's
"hurricane proof" home.


- Bob