The Warren Theater miraculously took very little structural damage considering it took a direct hit. The primary reason for this is the standard to which the theater was built - it was designed to be able to take a hit. Question is, why not require at least schools to be built to that same standard?

I strongly support the proposed bill in Moore requiring all new homes to have a storm shelter or safe room, and I hope OKC and Edmond get on board with that soon as well.

Why though, in tornado alley, are most structures not built with tornadoes in mind?

Simple - Cost. People don't want to pay for it.

Schools should seriously be looked into to be built to a higher standard, but like venture said, people don't want to pay for it.

As I was reading comments about the tornadoes on various news websites I noticed a lot of people asking, "why don't people construct their houses to withstand tornado strength winds? There should be a bill requiring homes to be built in order to withstand 200 mph winds." Which of course I thought was pretty funny.

For the cost of building my house into a bunker, I could just buy a storm shelter and spend the rest on tornado insurance.

I'm not an architect or in construction so I may be way off, but I think the Warren's structural integrity is more a side product of sound-proofing the auditoriums and buildings in general. You might find the same with other movie theatres, or at least standalone ones. I do know the Harkins is considered one of the safer buildings in Bricktown.

I don't doubt there will be some research into incorporating some of those theatre design elements into at least portions of homes.

I think most new schools are resolving this but a 40? year old building is another issue unless the school district has ran a bond issue for shelters. I thought the kids who died drowned in the basement? (Not sure on the facts of the situation but a basement is better than a safe room)
People need to resolve this with common sense and I'm sure that will happen and people will be happy to pay higher taxes for shelters, just don't turn it into MAPS4 or you'll get half the shelters half the size for double the money you were originally sold on.
But as far as laws and codes, should all houses and buildings be fire and flood proof?...in a perfect world. I think at least any school without a shelter should get a structural engineers letter on what they would say is the safest portion of the building for any worse case scenario. Luckily there weren't many more deaths.

It didn't take a direct hit

As a structural engineer, I can say without a doubt that the Warren is designed for code level winds. The code level wind load is based on a 90mph gust for 3 seconds at 33 feet in the air for Oklahoma. Based on the occupancy for the larger areas of the Warren, I bet that they had to up the importance factor based on increased risk factor, which puts another 15% onto the load based on a 90mph gust. This same increase in load applies for schools in modern building codes. You could attempt to design a full structure for a 200 mph wind load, but it will never be built due to cost.

So the Warren did probably take wind loads in excess of the wind load it was designed for. This can be attributed to safety factors that are applied in the steel and concrete codes when we design structures, so inherently there is additional strength in the components of the building. With this residual reserve capacities and the importance factor, it gave the Warren a fighting chance to withstand the brunt of the storm. Same goes to the Moore Medical Center. It may look worst for wear, but in reality it is really just the windows and cheap EIFS and studwork exterior that took the brunt of the damage. The framework of the building appears to be largely intact, and served it's purpose as it took a direct hit. But I will attribute the Warren's perforance in the storm to it's construction from concrete tilt walls (likely used for it's large span capacities and acoustical and insulating properties) and the type of connections inherent to that construction type. You can just look at all the light metal building type structures and see how they performed...

In reality, the biggest issue with structural collapse has to do with the interaction of the building's walls and roof system. The roof of the structures is treated as a diaphragm, which braces the tops of walls, collects loads as the lateral loads push on the walls and distributes it to shearwalls and frames that give a structure stability. I guess the easiest analogy I can think of is a cardboard box with a lid intact, which is pretty rigid, but remove the lid and the sides can be pushed and folded easily. In an extreme wind event, the speed of the wind over the top of the roof actually produces very high areas up uplift force on the roof surface, especially around corners and the sides of the roof. So if the roof connections to the support structure begin to fail, whether it be welds on a steel deck of nails on plywood, if it begins to lift off the structure at all, it allows wind to get underneath the deck and eventually start peeling away. If this happens on a large enough scale, then the entire roof diaphragm and wall bracing of a building is compromised, leaving walls without bracing or load paths to lateral load bracing elements and eventual collapse. So reality is a CMU wall may be designed for a 90mph gust, but could potentially withstand much more load without catastrophic collapse, but once the roof goes it doesn't have a chance.

I'm not an architect or in construction so I may be way off, but I think the Warren's structural integrity is more a side product of sound-proofing the auditoriums and buildings in general. You might find the same with other movie theatres, or at least standalone ones. I do know the Harkins is considered one of the safer buildings in Bricktown.

I don't doubt there will be some research into incorporating some of those theatre design elements into at least portions of homes.

They have, they are concrete safe rooms.

Safe rooms and storm shelters are adequate for homes, but there's no doubt public buildings such as schools and hospitals should be built to withstand a tornado hit. Same goes for high density housing that gets built in the urban core.

As a structural engineer, I can say without a doubt that the Warren is designed for code level winds. The code level wind load is based on a 90mph gust for 3 seconds at 33 feet in the air for Oklahoma. Based on the occupancy for the larger areas of the Warren, I bet that they had to up the importance factor based on increased risk factor, which puts another 15% onto the load based on a 90mph gust. This same increase in load applies for schools in modern building codes. You could attempt to design a full structure for a 200 mph wind load, but it will never be built due to cost.

So the Warren did probably take wind loads in excess of the wind load it was designed for. This can be attributed to safety factors that are applied in the steel and concrete codes when we design structures, so inherently there is additional strength in the components of the building. With this residual reserve capacities and the importance factor, it gave the Warren a fighting chance to withstand the brunt of the storm. Same goes to the Moore Medical Center. It may look worst for wear, but in reality it is really just the windows and cheap EIFS and studwork exterior that took the brunt of the damage. The framework of the building appears to be largely intact, and served it's purpose as it took a direct hit. But I will attribute the Warren's perforance in the storm to it's construction from concrete tilt walls (likely used for it's large span capacities and acoustical and insulating properties) and the type of connections inherent to that construction type. You can just look at all the light metal building type structures and see how they performed...

In reality, the biggest issue with structural collapse has to do with the interaction of the building's walls and roof system. The roof of the structures is treated as a diaphragm, which braces the tops of walls, collects loads as the lateral loads push on the walls and distributes it to shearwalls and frames that give a structure stability. I guess the easiest analogy I can think of is a cardboard box with a lid intact, which is pretty rigid, but remove the lid and the sides can be pushed and folded easily. In an extreme wind event, the speed of the wind over the top of the roof actually produces very high areas up uplift force on the roof surface, especially around corners and the sides of the roof. So if the roof connections to the support structure begin to fail, whether it be welds on a steel deck of nails on plywood, if it begins to lift off the structure at all, it allows wind to get underneath the deck and eventually start peeling away. If this happens on a large enough scale, then the entire roof diaphragm and wall bracing of a building is compromised, leaving walls without bracing or load paths to lateral load bracing elements and eventual collapse. So reality is a CMU wall may be designed for a 90mph gust, but could potentially withstand much more load without catastrophic collapse, but once the roof goes it doesn't have a chance.

Exactly correct. Thanks for taking the time to post this.

Safe rooms and storm shelters are adequate for homes, but there's no doubt public buildings such as schools and hospitals should be built to withstand a tornado hit. Same goes for high density housing that gets built in the urban core.

This maybe callous, but it frankly will never happen for an entire structure. It would just cost way too much. That's why they have saferooms, so they can isolate the cost into a smaller refuge area. One caveat that raises cost is the code states you have to have 5 sq ft per person in a safe room. So for a elementary school of 500, that's at least 2500 sq ft, probably more to account for handicap access etc.

Actually, I found this arcticle ( http://www.pci.org/view_file.cfm?file=AS-11SU-7.pdf ) and it really spells out the process really well including all the code issues that we face. It states: Many factors influence the cost of a safe room. Key factors include number of uses, design simplicity, windspeed design, debris-impact criteria, exterior wall and roof materials, and location with regard to foundation and site-development requirements. Costs generally range from $150-$240 per square foot, depending on geographic location and the secondary use. So these rooms can be built into a new school for a price, and I agree they should be. But this cost is going into a large overall project so the isolated price spike can be absorbed into the larger pricetag of the entire structure. But retrofitting all the schools in a district would be a large financial undertaking. Still it should be put to a bond vote to add these structures.

In reality, the biggest issue with structural collapse has to do with the interaction of the building's walls and roof system. The roof of the structures is treated as a diaphragm, which braces the tops of walls, collects loads as the lateral loads push on the walls and distributes it to shearwalls and frames that give a structure stability. I guess the easiest analogy I can think of is a cardboard box with a lid intact, which is pretty rigid, but remove the lid and the sides can be pushed and folded easily. In an extreme wind event, the speed of the wind over the top of the roof actually produces very high areas up uplift force on the roof surface, especially around corners and the sides of the roof. So if the roof connections to the support structure begin to fail, whether it be welds on a steel deck of nails on plywood, if it begins to lift off the structure at all, it allows wind to get underneath the deck and eventually start peeling away. If this happens on a large enough scale, then the entire roof diaphragm and wall bracing of a building is compromised, leaving walls without bracing or load paths to lateral load bracing elements and eventual collapse. So reality is a CMU wall may be designed for a 90mph gust, but could potentially withstand much more load without catastrophic collapse, but once the roof goes it doesn't have a chance.

Sorry to quote myself, but this above also applies to residential construction. If you can keep the roof on your home, you have a chance to avoid total collapse. If you are building a new home, you should insist on having hurricane clips installed from the trusses or roof rafters to the top plates of your walls. 3749 These framing elements are often toenailed in and have very little uplift capacity, and even less so when framers today work so quickly and haphazardly nail these elements down. These won't resist an hit from an F5, but would go a long way in helping save roofs in many high wind events.

It didn't take a direct hit

Kind of surprised this was skipped over. I don't want to take anything away from Bill Warren who has been nothing but class, but looking at the Google crisis map shows this to be true. The homes directly across from the Warren are still standing with minimal damage.

Google Crisis Map (http://google.org/crisismap/2013-oklahoma-tornado)

Yea, the tornado went north of the Warren, it did not pass over it.

Excellent posts KB.

I've learned a great deal this week about the geological problems with installing in-ground storm shelters in Oklahoma. Subjects that seem simple usually aren't.

I've learned a great deal this week about the geological problems with installing in-ground storm shelters in Oklahoma. Subjects that seem simple usually aren't.

There have also been a number of people coming forward that a lot of the obstacles people feel are against having basements are unfounded. A lot of it seems to come down to people not wanting to pay for it.

There have also been a number of people coming forward that a lot of the obstacles people feel are against having basements are unfounded. A lot of it seems to come down to people not wanting to pay for it.

Basements are one thing, sure, waterproofing and maintaining a fullsize basement would be a pain, but sticking a waterproof box big enough for 5-6 people just below the surface isn't that hard to do.

There are some places where waterproofing might be a problem, but just as many or actually far more where it is not. There's more than one soil type in the metro. Also, while houses in low-lying areas might have hydraulic challenges, those in hillier parts of town likely will not. There are plenty of older homes with dry basements in this town. I used to own one in Gatewood built in 1927 which stayed totally dry and required no heroics from the builder to do so. Overall, the "high water table" thing is a red herring. What probably happened is over years of re-telling - like kids sitting in a circle and whispering a story into each others' ears - the real reason became obscured and misinterpreted by the re-tellers.

The REAL reason we don't have many basements these days is because of our relatively warm climate. Follow me here: because our frost line is only about 18", shallow slab construction is practical (and MUCH cheaper). When poured-slab construction became the norm here (post-1950s), deep stem wall foundations became a rarity. In colder climates, builders might have to go 4' or 6' deep with a stem wall & excavate crawl spaces for water lines and other utilities. As long as you are that deep already, a basement is almost free. At that point, a builder can get more value out of the home without much additional expense by adding one. When fewer and fewer homes in Oklahoma were built with basements as the poured slab trend took hold, there became fewer and fewer contractors who even knew how to build basements. If you were in the basement-building business you moved elsewhere or you found another business. Nowadays if you want one it is comparatively expensive for all of these reasons, so people just don't do them very often. THAT is the reason we don't have basements. Most of the other reasons you've heard are generally inaccurate.

Sorry to quote myself, but this above also applies to residential construction. If you can keep the roof on your home, you have a chance to avoid total collapse. If you are building a new home, you should insist on having hurricane clips installed from the trusses or roof rafters to the top plates of your walls. 3749 These framing elements are often toenailed in and have very little uplift capacity, and even less so when framers today work so quickly and haphazardly nail these elements down. These won't resist an hit from an F5, but would go a long way in helping save roofs in many high wind events.


Very good information.

On the link below wind researchers have determined that for a fairly low cost homes can be made far stronger. The hurricane clip is one major part of the solution….But it might be better if we called them tornado clips in our part of the country. Stronger state building codes that require the use of cheap hurricane clips would be a simple solution to reduce damage, injury’s and death.

Texas Tech University :: Wind Science and Engineering Research Center (http://www.depts.ttu.edu/weweb/Shelters/WindProtection.php)

There are some places where waterproofing might be a problem, but just as many or actually far more where it is not. There's more than one soil type in the metro. Also, while houses in low-lying areas might have hydraulic challenges, those in hillier parts of town likely will not. There are plenty of older homes with dry basements in this town. I used to own one in Gatewood built in 1927 which stayed totally dry and required no heroics from the builder to do so. Overall, the "high water table" thing is a red herring. What probably happened is over years of re-telling - like kids sitting in a circle and whispering a story into each others' years - the real reason became obscured and misinterpreted by the re-tellers.

The REAL reason we don't have many basements these days is because of our relatively warm climate. Follow me here: because our frost line is only about 18", shallow slab construction is practical (and MUCH cheaper). When poured-slab construction became the norm here (post-1950s), deep stem wall foundations became a rarity. In colder climates, builders might have to go 4' or 6' deep with a stem wall & excavate crawl spaces for water lines and other utilities. As long as you are that deep already, a basement is almost free. At that point, a builder can get more value out of the home without much additional expense by adding one. When fewer and fewer homes in Oklahoma were built with basements as the poured slab trend took hold, there became fewer and fewer contractors who even knew how to build basements. If you were in the basement-building business you moved elsewhere or you found another business. Nowadays if you want one it is comparatively expensive for all of these reasons, so people just don't do them very often. THAT is the reason we don't have basements. Most of the other reasons you've heard are generally inaccurate.

Very well said.

Speaking of slab construction, I sure hope they do okay despite cracks that develop in them. In one new home under construction, I was surprised to spot a crack had already developed on it, and it extended clear across most of it.

Nothing unusual. Concrete is guaranteed to do two things: 1) get hard. 2) crack.

There are some places where waterproofing might be a problem, but just as many or actually far more where it is not. There's more than one soil type in the metro. Also, while houses in low-lying areas might have hydraulic challenges, those in hillier parts of town likely will not. There are plenty of older homes with dry basements in this town. I used to own one in Gatewood built in 1927 which stayed totally dry and required no heroics from the builder to do so. Overall, the "high water table" thing is a red herring. What probably happened is over years of re-telling - like kids sitting in a circle and whispering a story into each others' ears - the real reason became obscured and misinterpreted by the re-tellers.

The REAL reason we don't have many basements these days is because of our relatively warm climate. Follow me here: because our frost line is only about 18", shallow slab construction is practical (and MUCH cheaper). When poured-slab construction became the norm here (post-1950s), deep stem wall foundations became a rarity. In colder climates, builders might have to go 4' or 6' deep with a stem wall & excavate crawl spaces for water lines and other utilities. As long as you are that deep already, a basement is almost free. At that point, a builder can get more value out of the home without much additional expense by adding one. When fewer and fewer homes in Oklahoma were built with basements as the poured slab trend took hold, there became fewer and fewer contractors who even knew how to build basements. If you were in the basement-building business you moved elsewhere or you found another business. Nowadays if you want one it is comparatively expensive for all of these reasons, so people just don't do them very often. THAT is the reason we don't have basements. Most of the other reasons you've heard are generally inaccurate.
My great-grandfathers house was on NW 22nd & Robinson, the basement was a constant maintenance nightmare. Some areas could handle them at a reasonable cost but many areas can't without being built out at a very high cost. Concrete tilt-wall, precast or CMU type of construction will typically be able to withstand a whole lot more force than an EIFS/brick on metal stud type of construction if it is built right. To build a house to withstand a direct hit of an F5 is not realistic, you are talking about bomb bunker type construction because that is the type of physical force you are talking about, even commercial buildings are not built to that unless there are special circumstances (like the force protection built in the new federal building). No one is willing to spend that kind of money, a $100,000 house becomes a $750,000 house trying to enact something like that. Yes, houses could be built much better construction than the typical stick frame that is built today but it ultimately comes down to cost, most people would prefer to spend the money on granite countertops than better construction because they don't know any better and the home builders are building what they (and the banks) thinks will sell.

The basement in our house here in Aurora wouldn't be a very good shelter, the floor above is wood framed and could easily collapse on top of us in the kind of storm that hit Moore. You would have to build a basement like a safe room but then you have daylighting and fire exit code requirements which compromise the integrity of a basement in regards to structural integrity in a storm. Much of the problem is the in-fighting between the various groups that write codes, fire officials demand an exit and health people require natural lighting so you end up with a basement well and window large enough for a person to climb out of, the basements of old had no such requirements.

There are some places where waterproofing might be a problem, but just as many or actually far more where it is not. There's more than one soil type in the metro. Also, while houses in low-lying areas might have hydraulic challenges, those in hillier parts of town likely will not. There are plenty of older homes with dry basements in this town. I used to own one in Gatewood built in 1927 which stayed totally dry and required no heroics from the builder to do so. Overall, the "high water table" thing is a red herring. What probably happened is over years of re-telling - like kids sitting in a circle and whispering a story into each others' ears - the real reason became obscured and misinterpreted by the re-tellers.

The REAL reason we don't have many basements these days is because of our relatively warm climate. Follow me here: because our frost line is only about 18", shallow slab construction is practical (and MUCH cheaper). When poured-slab construction became the norm here (post-1950s), deep stem wall foundations became a rarity. In colder climates, builders might have to go 4' or 6' deep with a stem wall & excavate crawl spaces for water lines and other utilities. As long as you are that deep already, a basement is almost free. At that point, a builder can get more value out of the home without much additional expense by adding one. When fewer and fewer homes in Oklahoma were built with basements as the poured slab trend took hold, there became fewer and fewer contractors who even knew how to build basements. If you were in the basement-building business you moved elsewhere or you found another business. Nowadays if you want one it is comparatively expensive for all of these reasons, so people just don't do them very often. THAT is the reason we don't have basements. Most of the other reasons you've heard are generally inaccurate.

It is not all myths. I knew about ten families with storm cellers within a one mile radius of where I grew up, all houses built in the late seventies/early eighties, they were all flooded. None less than a foot, one up to five feet. After my parents moved to there newest house, my dad found while digging that solid bedrock so shallow that he gave up on trying to putting in an in-ground basketball goal for my nieces and nephews.

I never said there is no such thing as a leaky basement, or an area where it was tougher to install cellars than another area. In the story you recount, a single or a few inexperienced contractor(s) could account for lots of bad installations in the same neighborhood.

The problem is that there is a near-universally held opinion here that basements are just about impossible throughout OKC and Oklahoma, and it is simply not true & based on inaccurate information. Overall it is no more difficult to build a basement here than it is in most parts of the country, but it is more expensive than many places for the reasons I previously mentioned. Shallower excavation/foundation requirements here lead to less "free" opportunity to include a basement and more relative expense to a project if considered. If considering additional expense, buyers would rather spend it elsewhere. The lack of basement demand leads to fewer experienced contractors, which in turn compounds the expense issue.

If you don't believe me that the actual ENGINEERING involved in basement construction is overall no more difficult in Oklahoma than it is elsewhere, believe builder Caleb McCaleb, and Mike Hancock, the basement specialist quoted in this article (http://newsok.com/article/3834188) in today's Oklahoman:


...But misconceptions cloud the reality that basements still are options for houses in Oklahoma, said Edmond builder Caleb McCaleb of McCaleb Homes.

“I think there are many myths about why we don’t have basements in Oklahoma. The main ones are that our water table is too high and that our soil has too much clay in it,” McCaleb said. “If the basement is designed correctly, then water intrusion and ground movement are not problems with a residential basement. The walkout basements that we put in some of our homes are finished living spaces that look and feel just like the rest of our new homes.”


“Building a home with a basement in Oklahoma is not that different than in other areas of the nation,” said Hancock, an engineer and former Kansan who moved here with basement-building already under his belt. “With proper engineering and design, a basement can be adapted and constructed on any building site.”

On the Basement Contractors website, Hancock outlines three points he has been making for years:

• “Basements leak” — “Not necessarily ... improperly installed basements leak. In the past, many basements were installed with either no waterproofing or ineffective waterproofing. Today we use state-of-the-art, spray-on polymer liners and drainage systems that ensure your lower-level living space will remain dry and comfortable.”

• “The clay soils will cause my basement foundation to fail” — “No matter where a basement is located, soil condition must be addressed. The use of properly installed waterproofing methods and the reinforcing steel we use in our walls help prevent any potential problems later.”

• “Basements are dark and damp” — “A properly installed heating and cooling system can prevent the damp feeling and wall sweating that was common in older basements.”

The above articles are, to a degree, circular. They say that the problems of building basements in Oklahoma are a myth, but then go on to outline precisely the kinds of things that need to be done to build them correctly, going on to talk about polymer spray-on liners and drainage systems. And overcoming those problems is a costlier issue than many expect, and hence owners opt to a lesser amount of money elsewhere.

Not exactly. Waterproofing and drainage systems are required in basements all over the U.S.. Unless you are building in the desert, you are probably going to need them if you want a truly dry basement. The additional cost of installing basements here relative to other markets is mostly because excavation is not required here to the same extent as in northern markets. And since we can build on slabs, without deep footings, stem walls, and crawl spaces, we do. Because it is easier, and cheaper. Again, the commonly-held misconception in OK is that they can't be built for one reason or another, and that is simply untrue.

The Moore elementary school was very old. It was built in, what, 1967? Things were built differently back then.

From my understanding, an above ground safe room is rated up to 200 mph winds. The Moore tornado had stronger winds than that. It would have to be underground to withstand that. Cost, flooding, likelihood of a direct hit, chance of floor collapsing or water pipes flooding the underground, etc. Wasn't the elementary school tragedy also impacted by a broken water pipe where the poor kids were taking shelter?

Very, very sad, either way.

It's unlikely that a residential house is going to have a 200 mph plus tornado directly hit it. I would build a standard brick wood frame house. EF5s are rare, and the odds of your house being in the direct path and being leveled by such a tornado are very low. Cost vs. risk for me. A residential storm shelter in the backyard is a very good idea, but I don't have one and probably won't buy one.

What ever happened to community storm shelters? I haven't heard of one open in years.

What ever happened to community storm shelters? I haven't heard of one open in years.

I posted this under the thread about community storm shelters. They are going out of favor for reasons mentioned here.

Mustang Times, School no longer open as public shelters (http://www.mustangpaper.com/v2/content.aspx?module=contentitem&id=206939&memberid=1586)

The Moore elementary school was very old. It was built in, what, 1967? Things were built differently back then.

From my understanding, an above ground safe room is rated up to 200 mph winds. The Moore tornado had stronger winds than that. It would have to be underground to withstand that. Cost, flooding, likelihood of a direct hit, chance of floor collapsing or water pipes flooding the underground, etc. Wasn't the elementary school tragedy also impacted by a broken water pipe where the poor kids were taking shelter?

Very, very sad, either way.

It's unlikely that a residential house is going to have a 200 mph plus tornado directly hit it. I would build a standard brick wood frame house. EF5s are rare, and the odds of your house being in the direct path and being leveled by such a tornado are very low. Cost vs. risk for me. A residential storm shelter in the backyard is a very good idea, but I don't have one and probably won't buy one.

What ever happened to community storm shelters? I haven't heard of one open in years.

Moore has had its share of EF5 tornadoes. In the last 14 years, its been hit by two F5s, one F4, and almost hit by an additional F5 in 2010 and F4 in 2011. I would say if you live in Moore or OKC south of I-240, your chances of being hit are much greater than elsewhere.

Moore has had its share of EF5 tornadoes. In the last 14 years, its been hit by two F5s, one F4, and almost hit by an additional F5 in 2010 and F4 in 2011. I would say if you live in Moore or OKC south of I-240, your chances of being hit are much greater than elsewhere.

Actually, that's not true. It's all entirely by chance and the probability is still exactly the same in any area of OKC. There is no physical or scientific reason for large tornadoes to hit that area. It's like saying that if you win money playing slot machines every night for 7 nights your chances are higher than someone else. It just doesn't work that way.

Actually, that's not true. It's all entirely by chance and the probability is still exactly the same in any area of OKC. There is no physical or scientific reason for large tornadoes to hit that area. It's like saying that if you win money playing slot machines every night for 7 nights your chances are higher than someone else. It just doesn't work that way.

This! There is nothing scientifically proven to show that Moore is more likely to get hit by a tornado other than the fact that its in Central Oklahoma, which happens to be one of the most tornado prone areas in the world. Unfortunately, clueless out-of-staters who may relocate to this area will purposely avoid Moore for this reason and fail to take proper precautions, thinking they are out of the "danger zone."

Hurricane clips could be put in all newly constructed roofs today and it'd add at most a couple hundred bucks to the price tag of that home. It'd provide good protection up to EF3 storms and would likely save countless lives over the coming decades. But this state will never make it a requirement. I doubt any city in the metro will either. Folks are just opposed to anything like that, even when it's really a no brainer to do.

It'll be interesting to see what happens with schools. It's a bit shocking to think that the government can compel your children to attend classes in one of their facilities, but then feel it has no liability towards them when they're hurt or worse. I keep thinking about that .04% income tax cut that was just passed, and the annual $237 million that goes away as a result. That could build a lot of safe rooms in a lot of schools each year. We won't though because of cost and heaven forbid the government tell us to do something. I hate to say it, but the only thing that might change that is massive numbers of lawsuits against the state by parents of injured children. If the cost of defending or paying out lawsuits gets too great, then suddenly the cost of installing safe rooms isn't such a big deal. I doubt that'll happen either though, as folks here are often just too nice about things like that.

Actually, that's not true. It's all entirely by chance and the probability is still exactly the same in any area of OKC. There is no physical or scientific reason for large tornadoes to hit that area. It's like saying that if you win money playing slot machines every night for 7 nights your chances are higher than someone else. It just doesn't work that way.

Its these same low probabilities that will make the state or city government reluctant to force people to strengthen their houses. Hurricanes affect a much larger area.

Its these same low probabilities that will make the state or city government reluctant to force people to strengthen their houses. Hurricanes affect a much larger area.

From my OU meteorology…..Any given location (state wide) in Oklahoma will be hit by a tornado once every 250 years.
Since the panhandle doesn’t have that many tornadoes the odds would likely be just a little better for the main body of the state.

Hurricane clips could be put in all newly constructed roofs today and it'd add at most a couple hundred bucks to the price tag of that home. It'd provide good protection up to EF3 storms and would likely save countless lives over the coming decades. But this state will never make it a requirement. I doubt any city in the metro will either. Folks are just opposed to anything like that, even when it's really a no brainer to do.

As discussed in the Popular Mechanics article that I posted on a different thread hurricane clips and several other things such as the strengthening of garage doors are cheap no brainers.
This is an educational process that needs to happen. People who are aware of cheap methods that make new construction stronger really need speak up. We own that much too future generations of Oklahoma’s, since tornadoes are not going to stop occurring in our state.

Since we can reduce death, damage, wealth destruction, job losses and a lot of demand on social services this is something that each of us should learn more about. It’s a discussion that our state leaders need to have even if we have to make them have it.

Actually, that's not true. It's all entirely by chance and the probability is still exactly the same in any area of OKC. There is no physical or scientific reason for large tornadoes to hit that area. ...

At this point we have no more physical or scientific reason to say it is at exactly the same chance as any area of OKC than we can say it at a much greater chance.

Not exactly. Waterproofing and drainage systems are required in basements all over the U.S.. Unless you are building in the desert, you are probably going to need them if you want a truly dry basement. The additional cost of installing basements here relative to other markets is mostly because excavation is not required here to the same extent as in northern markets. And since we can build on slabs, without deep footings, stem walls, and crawl spaces, we do. Because it is easier, and cheaper. Again, the commonly-held misconception in OK is that they can't be built for one reason or another, and that is simply untrue.My parent's 60 year old house has a basement. It was built by the previous owner and it's easy to tell from the horrible finish of the walls and steps that it was not built well. It's bone dry. In the 52 years they've lived there it's never even been damp or musty.

Actually, that's not true. It's all entirely by chance and the probability is still exactly the same in any area of OKC. There is no physical or scientific reason for large tornadoes to hit that area. It's like saying that if you win money playing slot machines every night for 7 nights your chances are higher than someone else. It just doesn't work that way.

With all due respect, I don't think this statement holds up scientifically. Allow me to offer a case.

At the macro level, we know that the probabilities for a tornado occurring in the SE United States are higher than those in, say, the NW United States. That's due to geography, moisture flow from the gulf, southwesterly wind flow, jet stream location, you name it. Scientific, identifiable factors. This is not to say that tornadoes cannot occur in those other areas, but they are decidedly less likely. So you have a region with P(tornado) = x, and another with P(tornado) = y, with y > x, sometimes y >> x.

That's the macro discussion. Apply that to the micro level. The panhandle sees fewer tornadoes than central OK. Why? To a lesser extent, because of the same geographic and atmospheric factors that apply above.

Take it to the next-level of micro discussion - OK, Canadian, McClain, or Cleveland counties versus, say, Pottawatomie, Logan, or Seminole.

The point is that if there is a significant geographic variable that points to a "macro" level differences in airmasses, climatology, wind patterns, etc in two regions, that leads to a delineation of a differential risk in those regions, then there necessarily exists a boundary between those two regions where the probabilities are different, whether the boundaries are on a continental scale or a city scale.

Perhaps it comes back to another version of "which straw actually breaks the camels back." We don't exactly where that line that marks the boundaries is. Perhaps the line is so broad that it defies identification under current technology beyond a very coarse-grained region. And perhaps that region varies from year to year, month to month, week to week, even day to day. But I think the fact that there exists a boundary between lower risk and higher risk, and that boundary seems to exist somewhere right here in Oklahoma, to state unequivocally and absolutely that the process is random just doesn't ring true.

Offered in the spirit of good discussion..

It has been mentioned a couple of times that the kids that died at the school, died because they drowned in an underground area when a water pipe broke. While it was reported and repeated as fact, this is FALSE

Oklahoma tornadoes: Six May 20 tornado rumors corrected | News OK (http://newsok.com/oklahoma-tornadoes-six-may-20-tornado-rumors-corrected/article/3834329)

1. Children at Plaza Towers Elementary drowned in the basement. Six died from being covered in debris. One died from blunt force trauma. The school did not have a basement. Briarwood Elementary did not have a basement either.

It has been mentioned a couple of times that the kids that died at the school, died because they drowned in an underground area when a water pipe broke. While it was reported and repeated as fact, this is FALSE

Oklahoma tornadoes: Six May 20 tornado rumors corrected | News OK (http://newsok.com/oklahoma-tornadoes-six-may-20-tornado-rumors-corrected/article/3834329)

I knew that had been corrected, but the ME listed most of the children at Plaza Towers as suffocation.

My parent's 60 year old house has a basement. It was built by the previous owner and it's easy to tell from the horrible finish of the walls and steps that it was not built well. It's bone dry. In the 52 years they've lived there it's never even been damp or musty.
Again, whether you can or can't build a basement is very site specific, it would be hard at my parents house because the aquifer is so close to the surface at that point that the subsurface soils stays wet most of the time. My sister lives out by Lake Overholser, it would probably be difficult out there as well with the sandy loam soils and subsurface water. In other parts of the city it would not be an issue. We are doing a new CONRAC facility at the Louisville airport, about half of the footings of the fuel canopy needed no additional soil stabilization, the other half did because the soil was so poor. The column grid is 30 feet on center so it is easy to see you don't need much space between different soils to necessitate a design change.

Hurricane clips could be put in all newly constructed roofs today and it'd add at most a couple hundred bucks to the price tag of that home.

I'd like a homebuilder to either confirm or refute that statement because it sounds waaaay low to me, even at a retail price of $1.29 apiece (Hurricane Tie Double Plate Rafter Clip (RT15-TZ) at Aubuchon Hardware (http://hardware.hardwarestore.com/27-110-framing-angles-anchors/hurricane-tie-double-plate-rafter-clip-625988.aspx?utm_source=pla&utm_medium=cpc&utm_term=&utm_campaign=rkg&device=c&network=g&matchtype=)). 100 clips + $70.00 labor - that's not enough.

Friends are building a new house and he's a commercial construction manager. We met at the house yesterday and I noticed no clips, storm shelter, safe room, beefed up construction, nothing. He had been to Moore helping out two days last week, so he's seen it up close and personal. Married. Young child. Responsible husband and father. I didn't ask him why (I didn't want him to think I was challenging his decision), but he's got all the facts, his construction costs are less than yours and mine, and this is what he's chosen to do.

I'd be willing to bet a builder/framing contractor doesn't pay half retail for something like those clips.

The $200 figure may not be precise, but I bet its not off by much. Heck, even at $400 its a cheap and worthwhile construction upgrade. Wish I had done it when I built my place in 1998. Especially cheap when thought of in terms of percentage of whole home cost.

Honestly didn't think anyone would take "a couple" so extremely literally.

Several years ago I was actually quoted a priced of around $500 - 700 for what the builder called "tornado tie-downs," which were the same exact thing. With inflation it's probably a bit more now, but it would be safe to say we're talking $1,000 or less on a good sized home. For nearly any home you could build here, you are talking fractions of one percent in cost of the home. It's a no-brainer.

As discussed in the Popular Mechanics article that I posted on a different thread hurricane clips and several other things such as the strengthening of garage doors are cheap no brainers.

Thanks, found it and am cross-posting it here:

8 Ways to Protect Your Home Against Tornadoes and Hurricanes - Doors That Can Take Some Punishment - Popular Mechanics (http://www.popularmechanics.com/home/improvement/interior/8-ways-to-protect-your-home-against-tornadoes-and-hurricanes-heavy-duty-doors#slide-4)

Wow, Pop-Mech thinks it could be done for $300 for a 2,000 square foot home.

Makes sense regarding increased vulnerability at garage doors. Seems code could have in impact on this for single family dwellings by requiring garage doors to be hardened and/or encouraging detached garages.

The clips are generally easy to install. One could pick up a couple of boxes of clips and nails and install all the clips needed around a home under construction during a weekend if you deem your contractor's/builder's price too high. Just need a ladder and a hammer. Just be careful if placing the clip towards the finish side of a top plate, as it could cause the sheetrock to bulge around the surface if the install is not clean. Better to install outboard

http://www.amazon.com/Simpson-Strong-Tie-H2-5A-Hurricane-Tie/dp/B001AXCY46

Generally speaking this clip is rated for around 500lbs uplift per Simpson

http://www.strongtie.com/products/connectors/h.asp

but he's got all the facts, his construction costs are less than yours and mine, and this is what he's chosen to do.
When I was a kid I knew doctors who smoked, now that more is known about smoking and its dangers more people have quit or have never smoked and I know of no doctors who smoke…….. But that’s no guarantee that they won’t get lung cancer, but it improves their odds of not getting lung cancer. Not everybody in their field of work is always the most up to date on the latest scientific research.

I'd like a homebuilder to either confirm or refute that statement because it sounds waaaay low to me, even at a retail price of $1.29 apiece (Hurricane Tie Double Plate Rafter Clip (RT15-TZ) at Aubuchon Hardware (http://hardware.hardwarestore.com/27-110-framing-angles-anchors/hurricane-tie-double-plate-rafter-clip-625988.aspx?utm_source=pla&utm_medium=cpc&utm_term=&utm_campaign=rkg&device=c&network=g&matchtype=)). 100 clips + $70.00 labor - that's not enough.

Friends are building a new house and he's a commercial construction manager. We met at the house yesterday and I noticed no clips, storm shelter, safe room, beefed up construction, nothing. He had been to Moore helping out two days last week, so he's seen it up close and personal. Married. Young child. Responsible husband and father. I didn't ask him why (I didn't want him to think I was challenging his decision), but he's got all the facts, his construction costs are less than yours and mine, and this is what he's chosen to do.
My guess he's never had a close call with a tornado or been through one.

mm

With all due respect, I don't think this statement holds up scientifically. Allow me to offer a case.

At the macro level, we know that the probabilities for a tornado occurring in the SE United States are higher than those in, say, the NW United States. That's due to geography, moisture flow from the gulf, southwesterly wind flow, jet stream location, you name it. Scientific, identifiable factors. This is not to say that tornadoes cannot occur in those other areas, but they are decidedly less likely. So you have a region with P(tornado) = x, and another with P(tornado) = y, with y > x, sometimes y >> x.

That's the macro discussion. Apply that to the micro level. The panhandle sees fewer tornadoes than central OK. Why? To a lesser extent, because of the same geographic and atmospheric factors that apply above.

Take it to the next-level of micro discussion - OK, Canadian, McClain, or Cleveland counties versus, say, Pottawatomie, Logan, or Seminole.

The point is that if there is a significant geographic variable that points to a "macro" level differences in airmasses, climatology, wind patterns, etc in two regions, that leads to a delineation of a differential risk in those regions, then there necessarily exists a boundary between those two regions where the probabilities are different, whether the boundaries are on a continental scale or a city scale.

Perhaps it comes back to another version of "which straw actually breaks the camels back." We don't exactly where that line that marks the boundaries is. Perhaps the line is so broad that it defies identification under current technology beyond a very coarse-grained region. And perhaps that region varies from year to year, month to month, week to week, even day to day. But I think the fact that there exists a boundary between lower risk and higher risk, and that boundary seems to exist somewhere right here in Oklahoma, to state unequivocally and absolutely that the process is random just doesn't ring true.

Offered in the spirit of good discussion..

You make some valid points but some of those in the know don't agree with you completely about differences in such a small area.

This full article is currently only available to those with full subcriptions.

http://www.oklahoman.com/article/3840854


If you’ve lived in the Oklahoma City area for any length of time, you’ve probably heard many theories and superstitions about tornadoes. Where they come from. Which cities are safest. Which ones aren’t.

Rick Smith, warning coordination meteorologist at the National Weather Service in Norman, likely has heard all the theories.

As for the Canadian River and its significance to the formation of tornadoes west of Moore, Smith said he doesn’t believe there is any.

Smith said there is no scientific data that makes him believe that a river, or any other natural feature, causes or alters the path of tornadoes.

“They don’t cause, change, stop, turn ... tornadoes,” he said. “Especially rivers with no water in them.”


Smith said the city of Moore, which lies just to the east of the Canadian River, isn’t sitting on some doomed patch of land.

“Scientifically, there is nothing special about Moore to cause tornadoes to happen there ... more than they happen anywhere else,” Smith said. “It’s just chance, I mean, it’s just the way it’s worked out.

“That seems weird, but there is no scientific explanation for it.”

Smith said scientists know a lot about tornadoes and what conditions are like when they crop up, but “we only know a very short history of tornadoes.”

“When we plot all these lines on a map, that’s only 50 to 100 years worth of tornadoes,” he said. “If we knew what a thousand years of tornadoes looked like, they’d probably be evened out and there wouldn’t be clusters.”

Aside from rivers, Smith expressed serious doubt that other natural features can affect weather systems capable of producing tornadoes.

He said “there’s just no evidence that relatively subtle changes in terrain or geography affect tornadoes.”

“That storm that produced the (May 20) Moore tornado was probably 60,000 feet tall, 10 to 12 miles high, it was massive,” Smith said. “(Natural features) would just have nothing to do with what it’s going to do ... a bluff, a bend in the river or the interstate or anything else like that.

“Tornadoes cross rivers, they cross mountains ... into downtown areas, whatever.”

My point was about the immediate OKC area and not comparing this area to the panhandle or some similarly distant place.

I accept there's no evidence. Yet. One day we might find that a certain mineral count that lies in that area acts a magnet for tornadoes. Yes, I just made that up but that's my point. "No evidence" doesn't mean there isn't something, someway, somehow. Much of life is a mystery. There's so much we just don't know and understand. Yet.