# Wind test



## JBI (Oct 21, 2010)

http://news.yahoo.com/video/us-15749625/22532467

This is why we have codes...


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## Mark K (Oct 21, 2010)

This is why you need to engineer homes and why they need to be built according to the plan.


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## Jobsaver (Oct 21, 2010)

Mark K said:
			
		

> This is why you need to engineer homes and why they need to be built according to the plan.


Or, at least, an effective form of wall bracing, (prescriptive codes). Who really installs vinyl siding directly to studs? This video is an exaggeration.

It is true that shady contractors are out there building C.R.A.P. (Contractors and Remodelers Against Plywood), but, every home does not require a stamp.


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## vegas paul (Oct 21, 2010)

The whole purpose of the IRC is to prescriptively build a house WITHOUT a registered designer (architect or engineer).  But, you must do it prescriptively in every category/area.  It's not a smorgasbord where you pick what you want!  Now, of course, you can use an engineered design (and deviate from the prescriptive requirements of the IRC), but you don't have to.


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## Bryan Holland (Oct 21, 2010)

Anyone ever hear of the "Tale of Two Homes" story following Hurricane Charley here in SW Florida?

http://flash.org/video.php?id=82


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## Mark K (Oct 21, 2010)

I am not convinced  that the proscriptive provisions in the IRC will prevent the wind failure shown.  In addition the IRC provisions are regularly applied to buildings that may meet the letter of the code but are not consistent with the intent.


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## GHRoberts (Oct 21, 2010)

It is easy to build two homes and load both until one fails. The question that comes to mind is at what loading did the second home fail? Maybe it failed 2 minutes later - not a significantly better design. Maybe it failed at a 50mph greater wind speed - a significantly better design.

But we don't know.

We also don't know if other solutions that might be cheaper are better.


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## Robert Ellenberg (Oct 21, 2010)

They sepcifically said the failed house was built to standards used in the midwest.  Being a coastal state, SC probably has much higher standards and the IRC wind charts require higher standards for all but the most Western portion of the state.


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## JBI (Oct 21, 2010)

Prescriptive design cannot be used above the specified wind speeds and in hurricane prone regions, it's not strong enough. If you build a single family following the prescriptive provisions to the letter, you would have a home that is slightly better than the least you can legally build. An Engineer could actually design a compliant structure that is 'less'.


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## DAF (Oct 28, 2010)

The October 27, 2010 edition of the "Coastal Connection" has an article on this test.   Here is an comment in the article: "Explains IBHS spokesman, Joe King, “During straight line winds of about 110 mph, the front door of the home failed and blew open. Approximately four seconds after the front door blew open, the home was blown completely off the foundation and destroyed."

Maybe we need to improve the opening protections more?   How long would the building stood if the door didn't fly open?


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## mtlogcabin (Oct 28, 2010)

> How long would the building stood if the door didn't fly open?


DAF Welcome to the board

Any breach in the building envelope will cause a failure that is why a lot of changes came into the codes after hurricane Andrew with regard to wind loads and windows and garage doors. Agree there should be something for all doors.


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## brudgers (Oct 28, 2010)

mtlogcabin said:
			
		

> DAF Welcome to the boardAny breach in the building envelope will cause a failure that is why a lot of changes came into the codes after hurricane Andrew with regard to wind loads and windows and garage doors. Agree there should be something for all doors.


Actually, buildings can be designed to withstand breaches of the envelope. The just need to be designed as partially enclosed rather than enclosed. In their infinite wisdom (i.e. the need to support  insurance carriers) the IRC does not allow for partial enclosure.

A home designed for partial enclosure won't experience structural failure when the openings are breached because connections are sized for the additional load. It provides greater life safety than any kind of opening protection but is more likely to result in water infiltration and hence higher insurance claims.


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## Builder Bob (Oct 28, 2010)

The prescriptive codes want you to build a box - porch projection of less than 4 feet, wall height of no more than 12 feet, with a moderate pitched roof.......Otherwise it is an irregular buuilding and may require engineering...........................

If you don't want a box, get an engineer....


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## GHRoberts (Oct 28, 2010)

brudgers said:
			
		

> Actually, buildings can be designed to withstand ... The just need to be designed as ...


A good portion of building design is in the engineering assumptions. And the occupants ensuring the assumptions are true.

Typical tornado shelter design assumes that all 3 dead bolts are locked. Without that the door fails and the engineering changes.

One can assume that in a hurricane 3 dead bolts in the door will keep the door closed, but someone needs to lock them.

So does one pay a lot more for a "partially enclosed design" or does one trust the occupant to lock the doors? It is tough to set design standards.


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## brudgers (Oct 29, 2010)

GHRoberts said:
			
		

> A good portion of building design is in the engineering assumptions. And the occupants ensuring the assumptions are true.Typical tornado shelter design assumes that all 3 dead bolts are locked. Without that the door fails and the engineering changes.
> 
> One can assume that in a hurricane 3 dead bolts in the door will keep the door closed, but someone needs to lock them.
> 
> So does one pay a lot more for a "partially enclosed design" or does one trust the occupant to lock the doors? It is tough to set design standards.


Partially enclosed design can add to the cost of the structure, but structure tends to be cheaper than opening protection.

For what it's worth, typical porches, carports, screen rooms, etc. require design as partially enclosed.


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## RJJ (Oct 30, 2010)

I saw this on tv when it was first aired. The question I have is just what was the difference between the two structures? Was it a continuous wind or with gusts? Was the one that failed built to the prescriptive requirements or was what? Sorta of reminds me of the three little pigs. Should we jump to the conclusion that the home that failed wasn't built to code! What code was employed!


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## Belly John (Nov 1, 2010)

Fronts occurr at interfaces between presure cells or air masses, and are not features of the global wind belts.


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