Lesson from Bermuda

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saltysam

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Local Bermuda authorities are citing their heavy strong concrete construction techniques as the reason there has been minimal structural damage on their island. After taking a direct hit there are no deaths or serious injuries reported the morning after hurricane passage. I agree with this assessment.

Compare this recent Bermuda experience to most recent experiences along the US coast. Recall the wipeout of SW Florida a couple years ago. Fprt Myers area took a big beating. Frail, unhardened stick-built struscture just can't stand the wind loads of a hurricane.

All you folks who aspire to living in Florida should ensure that any property that you consider has heavy strenthened construction. I happen to live in a circa 1922 block and poured concrete house that is built like a army pillbox. It has never had any substantial damage--only water leakage from improperly caulked windows that were installed in mid-life renovations.

Either poured concrete or conrete bloak is the way to go--- reenforced with steel bars. New South Florida building codes provide excellent guidance. Any new construction within the southern hurricane danger areas should use them for reference

But any hurricane can be bad to anyone at any time. Good Luck!
 
I don't doubt that concrete is better than stick built, just ask the three little pigs. And poorly stick built is even worse. But I would think the bigger reason for lack of storm damage in Bermuda had to do with a catagory 1 storm vs. a cat 4-5 as has impacted FL on a few occassions. I've been thru a couple of direct hits of Cat 1's and, while scary, left little damage except for the immediate coast line and misc. downed trees. Storm surge and related flooding being the bigger problem. Cat 4-5 are in a different league. Again, I don't disagree with the premis but the lack of sevearity in Bermuda was a big factor.
 
I had a friend in Pensacola who lived in a "block house" very near the water .. he calls it his "bomb shelter". He rode our hurricane Ivan, and says they could hardly hear any noise, and sustained no damage!!!
 
good points there are many stick built houses and even condos. Ours is block with poured lintels leaving little for bugs to eat or wind to blow away. The roof however is always a question as few are made of concrete or steel.
There was an interesting report from Katrina of a former shipbuilding executive who built a bullet proof concrete house only to find that while it was still standing after the storm the ensuing mold made it uninhabitable. Storm proofing housing isn’t as simple as folks might expect.
 
"Hide from wind, run from water"

The last CAT 4 to his the US was Charley, Friday August 13, 2004.

Even Katrina was a CAT 3.

When wind is involved, protecting the building envelope is key.

This protects the building and all of it's openings from BOTH the POSITIVE and NEGATIVE pressures associated with the movement of hurricane force winds.

We have learned a great deal about BUILDING CODES since hurricane Andrew.

Charley proved that the codes DO in fact work.

RWS
 
Bruce hits on an intersting aspect--type roof and design. Wind is the force that is acting and one can soon get into a discussion of aerodynamics. If the roof starts to fail there will soon be a water problem. No, not simple. Then there is the expense factor. Custom work gets expensive quickly. Personal experience is limited to a common Florida flat roof with waterproof elastic-type coating applied.
 
I was able to view the result of a rebar reinforced poured wall, poured ceiling small structure on Gun Cay, Bahamas, just after Andrew raked it. The storm surge flattened it... But, truth be told, this little box was maybe 4' above sea level, and just a few yards from the surf zone. This was also the even that took down the guyed radio tower on that same island.
 
not many structures will with stand wave action.
 
how true.

my old house survive hurricane Luis on St Barth, in 1995. Luis was a 145MPH storm when it hit and a slow mover... took 36 hours to go over the island. It was built like most homes on the island: blocks with reinforced concrete at every corner, around every door and window, all steel bars tied into the floor slab and into a concrete belt at the top of every wall. that concrete belt had threaded rods tied into the steel to anchor the roof. Roof was trhu bolted with double sandwiched ply wood and foam, then shingles. Had 8' covered galleries in front which never moved in 145mph sustained winds.

this is how you built a home, not nailed matchsticks.

my house was up on hill facing the northeast so storm surge wasn't an concern. I remember some similarly built homes on teh beach that were destroyed when the waves dug in under them and they tipped over in the surf but the structure remained intact.

and as a precaution, it was pretty standard to have at least one room with a concrete slab under the roof... just in case.

there is no excuse for "expensive" homes to be destroyed by a mild storm.. yes, anything under 125mph is a mild storm.
 
Islands do not get hit by storm surge. The storm surge simply goes around the island. Breaking seas from elevated wind blown storm surge (28'+) is what destroys coastal homes on the Gulf Coast. There were several "hurricane proof" homes, on the beach, constructed of concrete, that did not survive Katrina. Try holding a 12" X 12" X 3/4" section of plywood in front of you in 30 knots of wind, you may rock back and forth a bit but you will remain upright. Try holding that same section of plywood against a 3 knot current of water, you will be swept away. While it is noble to commend the concrete construction of the Caribbean, the true reason they use Portland cement is that structural wood is too expensive, not easily sourced and not to mention the termite issue.
 
Yes...the strict local building codes are in place to prevent catastrophic damage to the building itself.

Foundations INTO SOLID BEDROCK, rebar reinforced and vertial to horizontal into walls and slab. Walls are all cast concrete blocks, solid pour lintells over every door and window (openings) and solid pour belt rebar reinforced rings the ensite building. Threaded rod out of the belt to hold down the wall plate that the roof rafters attach to. Mechanical ties on all roof supports..rafters and collar ties are bolted togther, not nailed. ALL internal walls (including closets!) are block and plaster...NOT drywall. The strong internal walls assist in keeping the building rigid and does not allow 'twisting'.

All windows are are installed into frames that are plastered into the building.

The roof is of course our local stone lapped are mortared over the roof frame. Air vents MUST be left in place to relieve the internal pressures. Generally, the roof stays on BUT when into a cat 2 or 3 eyewall with imbedded tornadoes, the roof cannot survive that...the crown tends to pop off. There are various new systems being tested to ensure the traditional Bermuad roof profile without using the stone base.

I agree that exposed homes in the US could do with a new bulding standard (stone - not stick frame) but some of the isses are related to the ground the house is built on.

A Bermuda house cannot be built in the central part of FLA where my brother is. My house is simply too heavy to be built. His house foundation is not set in bedrock - simply because there is none. Our houses do not allow for exterior wall insulation...a must for others), our roof system does not allow for insulation (a must for cold and extreme heat)

Some houses over here were exposed to hurricane force for over 12 hours without issues. Thats pretty damn good in my books.

Yes...Islands DO suffer from storm surge. Inland waterways and bay water heights rise considerably. For those who have ever been to St Georges town, the town square was underwater furing Igor, the water was over Ordinance Island where the cruise ship berths and where the deliverance is. We are smart enough not to build so close to the water.
 
Hey Bestmate, thanks for giving the details of how we build our houses. They are very solid. In 2003 we had hurricane Fabian, a very strong cat 3 storm which was also very slow moving. Nobody ran to any storm shelters. Basically, there are none. close shutters & stay at home.

Even where a bedrock to fix a foundation to is available I cannot see our building methods being done in the US. Our way is very very expensive, however, once built, the house stays put. As mentioned our worst enemy is a tornado within a hurricane. It shakes the roof leaving the rafters undamaged but the slate looks like loose chicklets ontop.

I missed Igor. Still in US enjoying 90 plus heat. Igor did get my 14' Maritime Skiff. It swamped then flipped at the mooring. My son got it out yesterday morning & had the engine running by afternoon.
 
Congratulations at the survival. Sounds like you've trained your son very well!
 
It's all in the building codes, gang. Bermuda is a relatively small island with a uniform building code that mandates construction techniques that are proven to be highly wind resistant.

I grew up in Miami in the 50's and 60's. Florida has no state-wide building code. Each county and even each incorporated city has their own building code that may or may not require wind resistant construction. The houses in the greater Miami-Dade area that were built in the 50's and 60's mostly stood up to all the hurricanes that hit that area when I was growing up. Then, in the 70's and 80's the large-scale developers managed to convince the local politicians to grant them waivers to many of the code requirements and very large developments with hundreds and even sometimes a thousand homes were built in areas like Homestead and Perrine. Its those houses that Andrew ripped apart and flattened. Go back and look at some of the post-Andrew photos and you will see clear boundaries where certain neighborhoods were literally erased and older neighborhoods abutting them suffered some damage but not the catastrophic ruin of the homes built by those builders who had obtained waivers.

The seeming insanity of not having a state-wide building code could be corrected if the residents of Florida demanded it. The local politicians don't want a state wide code as then they could not get as much money through legal campaign contributions and other means from the developers and big builders.

The post-Andrew Miami Dade building code is now a model for the rest of Florida, but to my knowledge not one single other county or incorporated city has adopted it completely. Some have adopted part of it and others have "recommedations to follow the Miami Dade code where possible".

I built a house in Titusville (near the Space Center) seven years ago and followed the Miami Dade code completely, but it was not a requirement. Local code says my roof decking could be made of plywood or OSB and nailed every 24 inches to the rafters. Every other rafter truss had to be fastened with a hurricane strap. My roof decking is all 3/4 inch plywood SCREWED to the truss every 12 inches and every single rafter truss has a hurricane strap on BOTH SIDES of the truss to fasten it to the walls. Every roof has hipped construction even thogh local code says gables are okay. I have twice as many concrete downpours in the walls than local code requires and larger diameter rebar in each downpour than required.

What's the point, you say? Well, my insurance company, USAA, liked the fact that I meet Miami Dade code requirements so well that my insurance costs half what each of my neighbors pays. Another point is that through the four hurricanes that hit us either directly or a glancing shot in 2004, the worst damage I had was some blown down palm fronds while several of my neighbors lost parts or all of their roof and spent months trying to get insurance settlements and repairs made.

Along similar lines, my wife and I rent a house in Key Largo every other year for several weeks in June for vacation. Last year while we were there I was fascinated to watch a new house being built across the street. It sat up on 12 foot high poured concrete pillars and the walls were solid poured concrete that was formed using foam forms and then they came in and made a poured concrete roof that was six inches thick and fastened to the walls with a hell of a lot of rebar. Although all of Key Largo is about a foot in elevation, this house should be there to be swallowed up by the higher sea levels 150 years from now.

Bottom line - we ought to have uniform building codes that apply across all states, zones and regions that have been hit by hurricanes - just like the Bermudans do. And while I do feel for the folks in New Orleans after Katrina, it is blind foolishness to build homes below sea level so near the coast and expect them to survive. It is also foolish to build high rise hotels and condos on transient sand bars like Miami Beach, Cocoa Beach, Fort Meyers Beach, etc.
 
"The seeming insanity of not having a state-wide building code could be corrected if the residents of Florida demanded it"

unfortunately people will not pay more for a well built home... they'd rather have a 4000 sq ft house that will sustain severe damage in a minor storm instead of a 2500 sqft home that will survive a cat 4 unscathed.
 
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