Hurricanes/wind/and round homes

[katfish]

I brought this topic up on another web site(N.C. cities). Builders of these homes
claim they will withstand major storms that level conventional homes. I guess its
the dome like factor. I've seen a few on the south east coast. Anybody have
info on this design? Any experience with these homes? Thanks.....

 

[wompo]

I was taking a look at these homes. Might be nice in an area prone to mother natures wrath. But, i am not sure I like how they look.

http://www.aidomes.com/

 

[Dawg52]

It makes sense but I have to say I haven't seen any in NW Florida or on the MS gulf coast. The design would take some getting use to.  

 

[unclemick]

Hmmm

The standard design I've seen on the Gulf Coast is the mini version of the big modern condo's - 'blowout structure on the lower level' and concrete/steel frame structure sufficient withstand 200 mph or so. Usually limited to 'upper end' housing developments. Well disguised - allows a lot of variety in design.

BUT - the building code has to right on the height - 15 feet was a bummer in my neighborhood - estimate was 35 foot storm surge in Katrina.

heh heh heh heh

 

[Rich_by_the_Bay]

I recall something about the "geodesic" configuration being astoundingly strong regarding shearing type damage from wind.

"Bucky Balls" aren't these the equivalent in nature, some sort of molecular arrangement found in certain physical systems? Maybe the nukes here can help me out.

The article I'm remembering stated that by squaring off the internal partitioning, there is only minimal awareness of living in a hemisphere. Rarely see them here in Tampa or in the nature coast north of here.

 

[ladelfina]

I think one issue with geodesic domes is the many joints they have that leave them perhaps more permeable to rain, (while strong winds, it's true, would not be a problem).

I remember seeing Fuller at a lecture long ago. He was an architect and 'futurist', not a chemical engineer or physicist. Like many architects of the time he wanted to solve the problem of cheap, yet durable, housing for the masses. He wrote "An Operating Manual for Spaceship Earth" and was into alternate housing, alternate energy, and just plain alternate.

Buckyballs I don't think are naturally occurring--just pounded into existence by dedicated scientists manhandling carbon into an unnatural form and named for Fuller after the fact.

 

[Nords]

Buckyballs I don't think are naturally occurring--just pounded into existence by dedicated scientists manhandling carbon into an unnatural form and named for Fuller after the fact.

Yup, they're named after Buckminster Fuller's geodesic dome.  Let's not forget that this was the same guy who patented his suspension of a hexagon from a tent pole...

I agree the sheer shear forces are one hurricane issue, and even if "dome homes" were more aerodynamic then their owners would still mess them up peelable fripperies like vinyl siding or roof shingles. 

Heck, why expose a home to the elements at all?  It'd be darn near invulnerable if it was buried 20 feet underground.  Well, except for subsidence and sump-pump failures.  And maybe this isn't such a hot idea near the San Andreas fault.  But it'd sure save a lot on roofing & windows!

I thought the bigger hurricane danger was the differential pressure and the missile hazards.  Unless you're gonna build like a submarine pressure vessel or a missile silo, there's not much you can do about explosive decompression & flying cows*.

(*My spouse the meteorologist claims that the American Meteorological Society rates the scientific quality of disaster flicks on their numbers of flying cows.  When your movie is named "Twister", the law says that you have to have at least one airborne bovine.)

 

[lazygood4nothinbum]

I thought the bigger hurricane danger was the differential pressure and the missile hazards.  Unless you're gonna build like a submarine pressure vessel or a missile silo, there's not much you can do about explosive decompression & flying cows

ya, it's mostly the flying cow thing.

while i have seen strictly wind damage, like a restaurant sign supported by two steel i-beams which andrew bent like an elbow, most  hurricane damage comes from storm surge, from stuff flying into stuff and from stuff falling onto stuff. shape not withstanding.

i think decompression is more a tornado problem. and while hurricanes, i suppose, are rather large tornadoes and certainly they spawn smaller ones, the big wind problem is a breach of the structure where the wind gets inside one section and then blows out other windows or the roof from within. not so much a difference in air pressure but a 120 mph wind coming through your living room. hey, would someone please turn off the ceiling fan.

 

[lets-retire]

I saw two of the dome houses on the beach in Charleston, SC. They were made form cement and of course had the parking underneath. They looked like a domed tent with the fly attached. If I remember correctly they could handle a 15' storm surge without getting water inside. They were supposedly built and desinged to withstand another Hugo.

 

[lazygood4nothinbum]

that assumes a proper foundation and it assumes the sand won't be washed away from the foundation. they might survive the incoming storm surge but the outgoing tide's gonna be a beach.

construction to truly withstand would consist not just of a watertight structure (where does the toilet vent?) with 1/2 inch windows just in case anything underwater taps at them, and not just of a piling foundation, but also you'd have to drive a sheet metal wall into bedrock to keep the sand around your pilings. i've only seen that foundation done to one of the very many condominiums we helped build. very very expensive and likely cost prohibitive for a house.

 

[CCdaCE]

I've had an affinity for building a concrete house for a few years now. But, I don't live in a hurricane zone or tornado alley, for that matter. I'd just like the "soundproofness", the thermal bonus of having a R-38 wall, "fireproof", etc.

Foundation washing away? Bah, that's what rip-rap is for.

The other thing to wonder about is bouyancy. Would your concrete cube float away like a boat?

-CC

 

[Nords]

not just of a watertight structure (where does the toilet vent?)

Speaking as a submariner, there's not enough activated-charcoal filters in the world to make this problem smell sweet...

 

[bbuzzard]

Speaking as a structural engineer who has designed many building on the gulf coast (none of which experienced any damage during Rita or Katrina) it is very easy to design and build a conventional wood framed structure that will easily weather the worst hurricane. The only question is do you want to spend the extra 20%, and can you find a contractor who will build it as drawn. The answer to both questions in normally no for residential construction.

As previously discussed, it is storm surge and storm surge debris that is the real killer. You may build a house capable of standing, but when two of your neighbors houses wash into yours, you may hurt. With a little reinforced concrete, you can even resist this.

 

[Rich_by_the_Bay]

bbuzard,

Does a brick house on frame (not block) stand up significantly better to surge and wind, than straight stucko or siding, or is it just another pretty face?

 

[lazygood4nothinbum]

Foundation washing away?  Bah, that's what rip-rap is for.

rocks help avoid some beach erosion during non-hurricane events, but as they are just sitting on the beach, they also will be undermined when that 10 to 15-foot storm surge retreats back to sea. besides, most beaches, at least here in south florida, don't utilize them anyway. we've got them to keep inlets open and i can think of one beach in broward which has them. but that's it.

Speaking as a structural engineer who has designed many building on the gulf coast (none of which experienced any damage during Rita or Katrina) it is very easy to design and build a conventional wood framed structure that will easily weather the worst hurricane....As previously discussed, it is storm surge and storm surge debris that is the real killer.

precisely. i've got a 1942 dade county pine cottage, frame-built tough for hurricanes. the wind is never a problem. however i've also got about seven 50-foot tall slash pines and a 50-foot tall sandbox tree surrounding the house and from how much i saw them sway in wilma, i won't be sticking around for the next one.

these pines are much heavier than northern pines. one came down on my neighbor during wilma. luckily it was only the top of the tree that got a corner of her porch. could have been nasty.

 

[astromeria]

I saw two of the dome houses on the beach in Charleston, SC.  They were made form cement and of course had the parking underneath.  They looked like a domed tent with the fly attached.  If I remember correctly they could handle a 15' storm surge without getting water inside.  They were supposedly built and desinged to withstand another Hugo.

The houses are on Sullivan's Island, a few blocks from my cousin and a few miles from me. They look like flying saucers. The local joke is that in a storm they'll lift off their foundations and ride the waves  My cousin spent that extra 20% to build her sturdy, but traditional beach "cottage."

 

[lets-retire]

Yep. those are them.

 

[bbuzzard]

bbuzard,

Does a brick house on frame (not block) stand up significantly better to surge and wind, than straight stucko or siding, or is it just another pretty face?

The only thing that will stand up to storm surge is a reinforced concrete structure with a DEEP foundation. Because this silly expensive, you have to elevate the structure above the surge. Elevated brick cost too much b/c the building is heavier, therefore most elevated structures of EIFS, Stucco or wood siding (or somthing similiar).

If your residential structure is not elevated above the surge, practically speaking it is dead. In regards to wind, block is best, past that they are all about the same (assuming they are built properly) becuase the wood backup is what provides the strength, and this is the asme regardless of what you cover it with.

 

[mathjak107]

years ago we were out caming in hurricane bertha in a tent no less....i have a 5 sided hexagonal shaped tent which withstood the winds just fine...of course here in nyc hurricanes are very different from down south in force but none the less mine was the only tent still standing...the wind couldnt hit any side head on

 

[lazygood4nothinbum]

the wind is stronger the higher up you go. at ground level, where your tent is, not so much wind. my garden grounds are covered in mulch and pine needles and i'm always amazed at how there is minimal disturbance in hurricanes.

but again, your tent would not have survived a high limb falling in that wind, regardless of its shape.

 

[CCdaCE]

In the May issue of Concrete Monthly (good readin'!) it has a article about debris.

"Debris driven by high winds presents the greatest hazard to homeowners and their homes during tornados. [even though we're talking about hurricanes] Laboratory testing at the Wind Energy Research Center at Texas Tech University in Lubbock, Texas compared the impact resistance of residential concrete wall construction to conventionally framed walls.  The frame walls failed to stop the penetration of airborne hazards.  The concrete walls successfully demonstrated the strength and mass to resist the impact of 100 mph wind-driven debris."

... gives some reference for windspeed, 100 mph is 100 mph, I guess.  Even though hurricanes and tornados both develop higher windspeeds.

-CC

 

[katfish]

bbuzzard

According to a N.C. modular builder (Deltec). There homes can withstand greater
force since they have no single flat section wider than eight feet. " this minimizes
large areas where wind can build and create pressure, which would collapse a
conventional square or rectangular home. The circular design insures any force exerted against one side of the structure is distributed out the opposing side."
So, (if true) it may be possible to build a conventional home that could hold up
as well but would it be cost affective? They also claim to have a one of a kind
roof system with optimal pitch to equalize any downward pressure or uplift.
What do you think?

 

[Leonidas]

Discovery Channel (or one of its clones) did a story on hurricanes and showed a house that was shaped something like a ship (a pointed "bow" facing the beach). Blow out lower level, massive concrete pillars all the way up through the structure, etc. But that was right on the water, a bit of overkill if you're farther inland.

If you're building outside the surge zone what I've read is that you have two concerns - both caused by wind - debris penetrating through windows (and even walls) and structural failure if the envelope of the building is compromised. The latter usually occurs when the roof goes as winds push up along the edges and too many roofs don't have hurricane straps/bracing (hip roofs seem to be somewhat resistant because there is no lip for winds to go under and push up against). But, if you lose a window from flying debris it would be much the same problem. The wind is no longer pushing on and around the house, but now is going inside.

Once the wind finds its way inside the house it is only a matter of time before the structure starts to come apart as the wind tries to find its way back out.

 

[unclemick]

Heh heh heh

The tree's - the stinking trees. Wonderful shade for years - then da hurricane.

Know two friends - well inland but the old trees bopped the house.

heh heh heh - if it ain't one thing it's another. BTY - I grew up at the foot of Mt ST. Helens. Mainly worried flash flooding in those days. Volcano - who'd have thunk it.

 

[Nords]

i have a 5 sided hexagonal shaped tent...

Is that cheaper or more expensive than a six-sided pentagon?