How design/build for flood & hurricane?
If you were going to build in an area such as New Orleans, which is susceptible to hurricane and flood, what designs and methods would you choose, keeping in mind the costs of various approaches?
No, I’m not planning to live there. I’m curious and I suspect many of you have some good ideas already.
Beej
Replies
As is done in all the close-to-the beach areas of the Gulf coast, and way up the Atlantic seaboard, build the houses up on piers or pilings, so that the first habitable floor is way up off the ground, then construct with materials, fasteners, and methods so that exteriors can withstand the positive and negative pressures that come from wind, and their penetrations (windows, doors, etc.) are designed and installed to not only handle the pressures, but can be leakproof as well in those extreme circumstances.
One of Cloud's domes should hold up pretty well under those conditions, esp. the wind part.
edit- I fergot the "l" in "cloud". Hit "post" just as I realized it.
Edited 9/13/2005 6:40 pm ET by Shep
Somewhere I read a story of a builder that jacks up houses in flood-prone areas and pours a concrete full first floor directly under the jacked up house. By using the first floor as a finished garage and for some kinds of storage, the main floor is high and dry. It sounded great at first, but right now after working up and down stairs all day it wouldn't be for me. :-)
Then your question made me think of ICF houses, but they are so heavy the foundation would need special attention to hold up well in totally saturated soil. The wiring and sheetrock would still take a beating in a flood.
Then there was an article on a house that was built in a potential avalanche area. The house/cabin wasn't inhabited during the winter, but they wanted it to survive if hit. The house was two stories and the bottom floor was essentially steel posts on the corner of the house with a thin breakaway garage. If an avalanche were to hit the walls of the garage would give way and let the snow pass underneath. Maybe a house on stilts could have a "disposable" first floor that would give way in a flood if there was moving water.
Finally, after thinking around in a semi-circle, it hit me that the steel mushroom house on the back of a recent FH would work just fine if it were a freebie (and an elevator was part of the package). :-)
For NO I'd at least build it 3-4 ft up... if cost was a factor... alot of bracing... sheer walls... min roof overhangs.... maybe a central filled concrete block core room... I know what i wouldn'd do I wouldn't put the back-up generator in the fick'n Basement.... that has to be the dumbest thing i ever heard... "our back-up generator in the basement was flooded"...
p
first you do not build in the city. go outside the city to high ground. fifty miles north would be good. 100 better. Then concrete, everything concrete. low pitch roofs, hip roof are good. gables concrete too. metal roofs. alot of anchor bolts, tie downs, all ulities underground. No trees by the house. patio covers, the first to go.Remember the storm surge wave that hit gulfport was 30 feet tall.
Edited 9/13/2005 8:29 pm ET by brownbagg
I vacationed a while ago in Maryland, on the shore, and the houses were built like Stinger describes. In this area they drove pilings thirty or more feet down. The problem is the force of a strong storm. Debris driven by the waves and wind can easily break out supports or undermine pilings, foundations or whatever you build on. Your house may stand the stress but the neighbors may come crashing into yours. Something like a tsunami could be high enough to break down and carry off just about anything. Just like the mud slides in California, when the ground gets displaced, everything on it or in it goes. If the big quake ever hits the west coast, Katrina will look like a spring shower.
Beat it to fit / Paint it to match
My brother's house is across Lake Ponchartrain from New Orleans, one lot from the lake. It is built up on concrete & steel piers and there is a concrete slab under the house where he parks his car. He had 3 feet of water under his house. The North wind blew the lake's storm surge away from the land which was why he had only three feet. Everything at the slab level was wiped out but it was only a storage shed and pump house. The codes don't allow much structure on the ground floor for this very reason.
The house is fine. The large pine trees fell like pickups sticks but they all missed his roof except for some branches which caused minor roof and siding damage. He was very lucky and very glad that he was required to build on stilts.
The knee surgery will come later but for now all the stair walking is good for their health.
Billy
Been there! done That! Have the T shirt!!! Wont ever happen to me again.
mk
History has shown that the houses that fare the best in a hurricane are those on driven pilings where the pilings extend to the roof line. Lots of hurricane clips, hip roof structure and a well secured metal roof. Of course none of that will protect you from your neighbor's house floating into yours.
20' storm surge means the finished space needs to be 20' off the ground.
Push a neighboring building into it and it is all gone.