These 3 Materials Can Create a Tornado-Resistant Home
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- Опубликовано: 10 июл 2024
- Tornado shelters serve to protect people at the expense of the destruction of the house. But is it possible to design a tornado-resistant home using wood walls and wood roof framing? Here's what I discovered.
Timestamps
0:00 - Intro
0:17 - What would it take to design tornado-resistant homes?
0:43 - Why concrete might not be the best solution?
1:58 - Structural design requirements for a tornado shelter
3:30 - Tornado-resistant home concept
5:24 - Final thoughts
Sources
ICC 500-2020 ICC/NSSA Standard for the Design and Construction of Storm Shelters
shop.iccsafe.org/icc-500-2020...
codes.iccsafe.org/content/ICC...
FEMA P-361, Safe Rooms for Tornadoes and Hurricanes: Guidance for Community and Residential Safe Rooms
www.fema.gov/sites/default/fi...
FEMA P-320, Taking Shelter from the Storm: Building or Installing a Safe Room for Your Home
www.fema.gov/sites/default/fi...
Texas Tech National Wind Institute
www.depts.ttu.edu/nwi/researc...
Thank you for the great jazzy music
Kreatev - Blue Coupe chll.to/ebf8628c
Toonorth - Dreamstate chll.to/15b48819
Disclaimer: The information presented in this video is for education purposes only and should not be interpreted as professional advice for any building. The information is not guaranteed to be complete, correct, or current. While this video is based on my engineering knowledge, judgment, and thorough research prior to the publishing of this video, you should not act on the basis of any information presented in this video without consulting a professional engineer licensed in the state your project resides.
Just use SR concrete 🤦🏾♂️ The wall would require nearly zero maintenance after a tornado. These walls will take damage during an impact.
I partially agree with you. If you watched the first part, I said that concrete is the correct approach... We all know reinforced concrete is the best method.
Now how do you suppose we break the barrier of creating reinforced concrete homes that are affordable for the average consumer? How do you suppose we build a workforce that can produce reinforced concrete homes starting today when wood construction today is also struggling to meet the demands? If reinforced concrete construction became the standard today, the costs to produce the materials, the labor costs, and the design fees for engineers & architects to plan & provide drawings would skyrocket. How do you cover for that?
It's extremely easy to point out the superior material... but nobody can or has made a dispute to any of the logistic & economical downfalls of reinforced concrete construction that makes it STILL a less likely solution that the average person would use today. So should we look for other ways that have been backed & tested to provide more protection and have a much better chance of withstanding a tornado with damage that can be repaired? Or is it just reinforced concrete or bust?
@@JthaEngineer I’m from New Orleans. Growing up we never had tornadoes. Now it’s happening on a year. The prevalence of tornadoes and hurricanes due to climate change will make the cost worth it. I live in Japan where earthquakes happen every day. A concrete house holds a lot more resale value than a typical wooden house. How man multi million dollar wooden homes were destroyed in California wild fires?
It’s a no brainer. Why are we building so cheaply in the first place?
You’re going to pay one way or another.
@@JthaEngineer oh and what’s the higher cost of concrete over the stronger wooden house not the typical house?
@@JthaEngineer I wouldn't say RC building is intrinsically costly than wood construction house. That's more to do with demand & supply. Look at Asia, Europe ...etc where RC is commonly in use. The cost for building is even lower than in US.
If people is aware of the pros and cons of RC building and starting to use widely. I am pretty certain the cost will go down.
@@JthaEngineer using concrete block is a step. 8 inch concrete blocks are relatively cheap easy and fast to work with. Then using rebar and 100%cell fill which would take around 2 trucks of concrete for the average home and it seems like you would have a pretty good home. That being said your design is quite the improvement over the relatively lousy construction standards of today. I would suggest coupling your design with a 24 guage standing seam metal roof and using zip system sheathing instead of regular plywood for increased waterproofing since all the hard work you did would be for nought if water penetrates and causes rot. I think matt risinger has some great insights in this area however his strategies are usually far from cost effective for the average person.
I had a house built last year in Tacloban City, Philippines, where I am now retired. The Philippines is in the "Ring of Fire" so we have earthquakes and typhoons multiple times per year. The worst typhoon in the history of the world, Yolanda, touched down in Tacloban in 2013 with a 20ft surge of water from Leyte Gulf, killing 20,000 people and completely destroying nearly all the buildings in the city. So, our house is of course concrete as are all new homes. Nearly all concrete buildings use hollow blocks, not poured concrete. Ours also has rebar going through the blocks vertically and horizontally and those spaces are filled. Ours is on a 400sqm lot (1/10 acre) and the house is 2-story with a finished flat concrete roof and a medium-sized room on the roof to protect the stairs and give entrance to the roof. It can be used as a 3rd living room since we have one on each floor. And we have a 2nd floor tiled patio and a 2-car tiled carport. The total floor space is over 5000 sqft. They no longer build wooden homes here, unless you're extremely poor and then you build them out of any junk you can find. These shanties always lose their roofs in a typhoon and most are completely wiped out. Besides, good lumber is difficult to find because there isn't much of a lumber industry. Coconut lumber is the most common dimensional lumber, but is only used for shanties and scaffolding because it is the lowest quality wood. Hardwood is rare, protected, and expensive and not processed properly. Homes are built with deeply set reinforced concrete pillars with a wide cage of concrete at their base. Our home has 25 pillars. I think the depth of the pillars is 2-3 meters. Each is then connected to each other in trenches. No one builds basements here because of the high water table. The property was filled with rocks and mountain soil so it is about 1+ meters above the road. All the floors are concrete with rebar and steel decking sheets and finally tiled on top of that. We have an 8+ft high perimeter block wall on the property edge and a 3-story concrete firewall on the side of our neighbor. Our house will probably withstand any structural damage from a typhoon or an earthquake, but the windows are vulnerable.
Hello Sr, this may be a bit late, but could you tell me how good it is to live in the Philippines? What are the pros and cons? And Would you recommend it for a middle age couple ? Tnx for your time 😊
I think we have to start thinking out of the box.
Thank You for sharing this valuable information , and the work you put into this well done video production. it is still helping the public stay safer two years now. I am building in Florida and plan to use these methods . You are a credit to your country and your parents who raised you.
I agree, we need more education on proper concrete and brick building material use here in US. I grew up in Eastern Europe and all they have there is concrete.
The only problem I saw with that is the many cracks in walls of practically all building there, a lot more maintenance is required for concrete and bricks/cinder blocks.
I suppose a hybrid type of house would be better, some concrete, some steel, some wood.
Maybe also changing from a square shape to a more aerodynamic and better load bearing shape would be good too.
We need to experiment and make it cheap so we can use storm proof designs as the de-facto building type.
Maybe we can protect homes from storms, fires, floods, and earthquakes all in one go for similar price if we build correctly from the start !
Living in the red zone I gotta say thanks to you!!!
Appreciate it!
Thank you for your information, I've been working with RC structures for the past 40 years in many countries in Asia and Africa, Tornado resistance homes are really needed in the RED zone. I think upper-middle-income family homes will be a good choice while affordable housing is not. The challenging issue is how to convert an existing house into Tornado cat 5 resistance. It's something I am working on for the past 10 months and the results are promising. Reinforced Concrete is the most feasible and economical solution.
I have thought long about this. I grew up in Kansas.
My idea for a home is simple. A single ridge home down the middle. about 20 feet wide, and XX amount of feet long. Whatever you need, want, or can afford.
The basement is where you and your family live.
The walls of the basement are ICF to keep you warm and cool. The ICF walls support the ground level of the house. The basement has an inner wall of concrete block that is filled with cement and reinforced with rebar of course. There are bolts sticking up out of the concrete. Installation of large steel plate spanning the basement is a simple matter but costly. Bolt the plate down to the concrete walls. This forms the ceiling which nothing can get through. Since it is level with the ground, you are safe.
All valuables are stored in the basement. And all bedrooms are in the basement. Ground floor is where you store things that can be replaced. Like the kitchen stuff, the tv, the cars, the dishes and dining table. The tools in the garage.
Everything important lives in the basement.
Obviously you will need to have evacuation ability in each room. in case of fire. Good air circulation, and double sump pumps to ensure no flooding with easy access to repair them.
Bathrooms in the basement with showers. And a kitchenette.
People don't like the idea, because you don't get alot of sunlight in the basement.
I vote for safety while sleeping. A tornado at 3 am during a new moon and pitch black storm clouds is not my idea of a fun game of guess where the twister is at.
Thanks Jay. This was very well done.
Some of what you describe was used 100+ years ago... I live in a 1914 foursquare, the main floor is approx. 30" above ground level. The walls are sheathed in 1"×6" "ship lap", which is also used as subfloor. The walls are and structural lumber is southern yellow pine, which is as hard as iron. On top of that, the siding was wood also which contributed to it's strength...
Compare this to "modern" construction where the walls are sometimes sheathed in 3/4" or 1" foam insulation board and covered in either vinyl or aluminum siding!
Great video, we the wife and I just bought a house in the red zone in Arkansas. When we remodel we plan on making improvements to make the house more tornado resistant. Looking forward to more research on this topic to make my home safer. Great start.
U know whats pretty funny theres a company out there called Bamcore that make prefab walls that do a really good job stopping 2x4's shoved into bamboo panel walls @ 60mph, idk if they work at 100MPH+ but it think its prettty dang cool in building more structurally sound homes. Bamboo imo is a severely underrated construction material.
I found this quite helpful thank you, we live in a high wind zone in NZ
Great stuff!
If you want a tornado proof home
Pumicecrete is by far the best building material on the planet Pumicecrete is a mixture of pumice cement and water mixed and poured into a set of reusable forms walls are poured from 12"to to 25" thick pumicecrete is fireproof termite proof rust rot and mold proof non toxic and has a high R value and good sound attenuation solid poured walls means no critters can live in your walls Pumicecrete can be built for a fraction of the cost and time and pumice is one of the few building materials that can go directly from the mine to the job site ready to use without any additional possessing and zero waste
Take care Ray
This is awesome information! I am someone crazy paranoid, just on a windy day. (Been in 3 tornadoes and 3 micro bursts in the past 10 years). Given how unexpected and unpredictable, we have decided to construct our own home. We are no more than in the planning stages. But one part of the plan thus far, is the foundation. I am old school and prefer pier and beam. Current plan is concrete piers going 6-8 foot deep into the ground (central texas), the beam will be steel I beams anchored to the piers. (Oh and where the footings of the walls cross over the I beam, they will be anchored all the way though the steel beam.
I have been planning a part of the house to be concrete, but after seeing this, may look into steel sheathing under the OSB. I am personally planning to build this house, but will bring in contractors to help complete the foundation, insulation (spray), etc.
Thanks for the info!
I am a Swiss architect looking into tornado proof housing, because last month, we had our very first (!) tornado with huge damage in Germany. I find your project very interesting, and if I would be living in the US, I probably would do the same as you plan to do now.
However I stumbled over the last part of it: spray insulation, and I would like to share my experience.
In Switzerland we have quite a few regulations on our building material. Spray insulation is on the black list, partly because it can crumble after some years, particularly when exposed to heat, and partly because the gas used for spraying is poisonous to the environment. Also a house insolated with sprayfome is not breathing anymore, together with highly insulated windows that can cause mildew to grow inside your house. Styrofoam has the same problems and is also highly inflammable.
There are other materials for insolation, for the most part here we use glasfibre mats (don‘t forget wearing masks and gloves). There are also new materials like hemp or sheep wool, that could be looked into. They need to be protected from dampness though.
It is always possible that you have a different kind of spray foam, however I would do some research, if you want to build a high quality home. It would be a pity, if one part of it was not up to standard. Insulation is difficult to replace without a lot of work 😉.
I wish you luck and a lot of energy for your project!
The choice between pier, perimeter, and slab also depend on site soil type. Pier in sand is difficult unless you're just going to dig out the whole area because of how hole edges fall in. But it'd work in clay very nicely.
Very interesting concept. I live in South Dakota where we have had near-miss tornados experiences.
Near-miss wouldn’t that be a hit?
Yes! Thank you for this well done video!
We need to shift federal petroleum subsidies intended to keep fuel affordable to help climate positive, climate-resilient housing and infrastructure projects create climate positive jobs that really help families get housed, build wealth, and stay housed so they can build social support networks instead of just reacting to the latest climate-change-driven disaster. There is a reason why Kentucky was hit by such devastating tornados: Kentucky coal mining and combustion generate CO2 that increases the amount of heat energy stored in our air which intensifies the power of storms. We must adapt and mitigate that or the storms will just intensify even more...and give us even more to cry about. How many of the families whose homes have been destroyed could still be comfortably enjoying their homes now if we could just be more scientifically intelligent about our energy use, our design, our construction, and our transportation?
Agreed
This is great work.
Appreciate it!
As a carpenter /builder. . I have always gone hardcore in building . Just for instance .. Granted its not an exterior element .. When I set doors . I developed a way to set them so perfectly. By using a PLS laser . Checking for floor deviation ,then primary projection deviation in the plumb of the four points of frame .Then setting the door with extreme accuracy by tracing an anchored hinge . The using glue on the shims ,dovetail nailing at slight opposing angles and 3" tempered steel screws through the hinges and all locations . When done . . I slam the door violently . Hopeing to break the trim free and knocking the stop off .. The house will move before the door does .. I pity remodelers in the future that try to remodel one of my homes .. Pertaining to framing ..I have many rules .. " Gather strength whenever you can " It can be in nailing patterns . The application of glues , The lacing together opportunities of framing members . Analysing the wood for weakness . When the video started .. Even before the word was uttered .. " Concrete !!! " ... In frame . Low slope roofs act like wings and create high and low pressure uplift . 90 degree corners create vortices and unequally distributed wind loads . The uplift and load pathways need the be continuously bonded to the base . Nature seems to be the greatest engineer .. I guess the best structure would be one that is cylindrical that creates no eddy . And better a bubble that can take forces in all directions .. But bubble houses don't seem to be what people want Lol . I build mansions and the customers want detail . Many have safe rooms in the event of a tornado or The Apocalypse . I have thought before " Well it might take a few days to unearth you with all that rubble atop " .. I guess the goal is . To make it more durable in an F5 . Instead of watching the house sucked off the foundation and clinging to the pipes in a central bathroom
I didn’t mention anything about the design of the shear walls so I’ll say something here.
The 3/4 plywood is the element I used to check if the shear walls were adequate. They would need hold downs. It is logical to say the steel plate also contributes to the lateral stiffness of the building but I’ve never heard of anyone doing this in a wood building so I ignored that.
That steel plate was armor. Pure and simple. The plywood is the shear element.
Nice work, Jay! A cost analysis vs, concrete construction would also be helpful…
Great videos!
Thanks! Appreciate it
Well done!
I Make Round. The ancestors did it for a reason.
Nice video! Hey, ya never know when a hurricane comes a knocking!
Hella Cool!
Great video! Thank you for sharing. Spray foam for attic insulation is like glue.
Hey Jay, again awesome content, congrats on thinking outside the norm, I'm an ICF builder in Australia 🇦🇺, trying to be better with a passive home using self healing, green concrete, but you have touched an idea I've had for those difficult sites on sloping hills nearby stormy ocean storms but have almost impossible access for heavy equipment, by implementing your design although light weight but easier to carry into a site up a hill with lighter equipment, where we can use screw piles to anchor the footings to the hill then booker rods ( threaded bar) from footings to top plate spaced evenly, then tie down the roof at the booker rods as well there for ancohing the roof through to the screw piles, I'd be interested in a detail that I could adapt to the Australian standards, thanks mate for the inspiration.
😀👍🇦🇺 🇦🇺 🇦🇺
I’m not sure this response is in line with what you’re describing but I’ll give it a quick shot. I think if you lined up the wall studs with the roof framing and used a heavy duty metal fastener to tie the roof directly to the stud, you’d still have a complete load path that would take those forces right down to the foundation.
Love this concept! I hope it's been tested since. I'd rather have a small home with this kind of structure any day over a larger standard one.
Given that we haven't had a tornado in decades, where I'm from, I never knew about what kind of research had been done in this field. Interesting stuff.
I'd suggest that shutters for the windows would be a good idea, though. Sorta like what you'd see on really old houses, but strong enough to withstand those impacts. Much faster to close than to temporarily screw sheet metal to your window frames.
how does this video not have a million views
Basements save lives. Period.
Not always... in a strong tornado if the house is blown off the foundation, unless you are under something reinforced you are still exposed to flying & falling debris.
In the Parkersburg Iowa EF-5, one person was killed in their basement when a pickup truck was dropped on them!
@@timnewman1172 I watched that storm from Prairie Du Chien. That unfortunate death proves that tornados kill. We know that. But they rarely kill multiple people where there are basements, compared to those areas where there aren't. Similar strength tornados almost always take more lives where the houses are slab on grade.
Lots of places in the south can't have basements though
@@gabbie39 true. If I lived there I'd build a storm shelter of some sort.
A family died this year in their basement
Thanks very helpful. I planning a custom house in tornado country. And I'll likely use Insulated Concrete Forms for the walls. But I've been at a loss as to what to use for the roof and it look like a typical gable or hip roof. The testing showing 130 to 133 mph penetration gives me one option for a wood framed roof. And based on what I know from playing tank games. Angled armor is stronger from penetration than flat. So it should survive everything but a direct hit from an F5 tornado.
Used to think about building a dome home, but wasn’t sure how to maintain it and keep it from leaking. Maybe time to reconsider.
Very interesting video with lots of research data to back it up. Just wish authorities and communities would get involved more actively in finding such solutions to tornadoes and hurricane problems that have been here for ages, rather than only focusing on reconstruction and more funding, all the time!
Amazing video dude. That would need some extra welding to be done to make the whole roof,walls and foundation to be connected as one structure
Concrete and rebar
Lessons learned from 200+mph tornado damage. We were in the house. I'm trying to rebuild a stronger house. Straps over top plate broke. Roofs system all gone and half of top plate gone. 90% of wiring gone . You can build for wind resistance and projectiles such as 2 x 4s. But building for the impact of a mobile home frame, or a 4 x 6 or 6x6 piece 5 or 6 feet long steel fence post. Ceiling fan motors. These things beat the hell out of my house. 40 space seimens 200 amp load center pull through brick wall along with studs it was attached to along with it. Beams 10 to 15 foot long from porches and carports moving fast through the air . Is it even possible to build to resist that type of projectiles. I'm building back as strong as I possibly can. My advise is build as strong as you can but make sure you have storm shelter or super strong safe room to get into to ride it out. Whipping winds at 200 + mph is one but what that wind is blowing with it is a game changer. We were in a fiberglass tub shower combo all fasteners pulled through fiberglass and unit lifted up about 3 inches. If I had steel ball for a house it would have a safe room. I saw things and took pictures of things that put chills down my spine. The stronger the better. The safe room needs to be in the plan. We took a direct hit from core of 2-1/4 mile wide EF 4 on 4 /12/2020 and 2 and a half minutes of violent destruction unimaginable and you're along for the ride weather you like it or not until its over. Homes are expensive and important. But first and foremost of all make sure the people that mean the most to you will survive . You can replace or repair the house. Have a plan to be alive and well to see it happen.
Just my opinion from past experience. I learned some hard lessons that afternoon in South Mississippi. Easter Sunday will never be the same. Thankful to be able to get out on our own 2 feet battered and bruised and alive
I appreciate that you've labeled this video with the term "Tornado Resistant" rather than tornado proof, because that's virtually impossible. I mean, the Fukashima scale only goes up to 5, but that doesn't mean tornados stop getting stronger. I've seen 30"+ Hickory trees twisted off like matchsticks and a swath of bare earth (I mean no grass, no anything, just dirt) a mile wide stretch for thirty miles.
@@protonneutron9046 What are you talking about? We're not discussing construction costs.......
3:41 - Tornado's don't really 'suck' up buildings, it's rather the pressure difference between inside and outside the house that makes the roof BLOW off, just by the sheer air pressure inside the house. It's vital to have rooftiles that contain air pressure equalizers to keep the difference as low as possible.
I imagine that windows - and garage doors in particular, lots of single car garage homes get absolutely blown up by tornados - are the weak points when it comes to that pressure differential causing the explosive removal of roofs. As you said, some sort of air pressure equalizer for the roof/attic space would be absolutely necessary.
My home is a 1920s brick/block home with deeply inset windows. I wonder if some sort of system of shutters which are capable of withstanding that pressure (some sort of seal perhaps?) would also help isolate the interior of a home from that huge pressure differential while also surviving 130-200mph wind and debris.
Man if you look at that Andover Kansas video from 2022 it sure looks like the houses are getting “sucked up.” Ultimately suction is just pressure differential where low pressure of the tornado is “pulling” on the lower atmosphere/ objects on the ground.
If you understand how they form you'd go with stuff being sucked up. As the funnel forms it doesn't touch down until a port opens behind the funnel. Just like any vacuum it won't suck unless it's ported, when this hole opens up it becomes ported and voila you have suction. It's nature's vacuum
I live in Tornado country.
I'm building an IFC house with a full basement, in floor heat and an overbuilt roof with rafter brackets set into the concrete.
I was out with some friends in Houston and we drove by a new housing area, the Philipinos I was with were shocked we built with wood,, they build (smaller) with concrete blocks due to all of the storms they get. they lift the better furniture up off the ground and go 'take cover',, when they return after the storm the power wash the floor (also made of concrete) put the furniture down and go about their lives. I have been thru a lot of hurricanes and tornados. in hurricane zones they use hurricane straps on every exterior board to the seal plate and rafter. tornado zones should do the same. if you notice 'hurricane proof homes' are curved outside the home.. a lot like your car,, the wind rolls past and many of those homes are made of a styrofoam!! now of course we would want something more than styrofoam to protect us from flying boards, but you can curve plywood.. or build igloo style.
The answer is to build houses underground. The cooling and heating expenses are eliminated. Geothermal is the way to go. Shipping containers maybe a great prefabbed material.
I’m very curious how an earth ship would do in severe storms.
@@vermontmike9800 I imagine they'd be great. As long as they are built in an over engineered manner lol.
Radon is a huge problem in tornado alley, especially Iowa!
A lot of people die from floods from the thunderstorm that caused the tornado. Underground is not the way to go.
Build underground, or steel rebar re-enforced concrete dome. The main problem is wind pushing against a flat wall.
I'm remodeling...rebuilding a broken down house in Mississippi using your wall/roof design!
I’m from the Dominican Republic, where hurricanes are expected. All homes are made out of concrete except for the older ones and in very rural areas. I still can’t wrap my head around why this is not the norm in the US where you have not just hurricanes, but also TORNADOES!
Dont forget underground potential!
Add skylights that would suck out or open when the pressure changes
I would just focus on keeping the structure from collapsing. Ok, maybe use thicker sheathing or something for the outside walls, but I would guess that puncture damage isn’t a huge issue in real life. If an object punctures your wall but the building is held together with hurricane ties and other strapping plus framing to withstand uplift or wall collapse, I think you would be fine. If a piece of 2x4 puncture a wall, just fix the puncture area after the storm. Replacing some siding and one punctured piece of exterior sheathing plus a section of drywall inside isn’t a big deal. It costs way less than cladding a home in steel under the siding. That would be very costly.
Regarding the cost of reinforce concrete... Explore alternative materials... Basalt has been making inroads within the construction industry.... monolithic dome with laminated structural members...
My house has a wood foundation. I am finishing the basement with a second framed wall of 2 by 6 bolted to the existing concrete pad. With further looking on line I may need to double the 2by6 and add heavy duty hurricane ties on top and metal brackets for the bottom. Realistically what else can I do to improve the strength of this inner safe room?
Rebecca
homes in south florida are all masonry homes and they still get destroyed by tornados. i think the reason why safe rooms work so well instead of whole house it is because they're small and compact and could bind a lot stronger. A whole home you have to worry about windows , door, garage, roof, and walls. if you dont have all of that put together the whole house can come down with increased pressure due to the heavy concrete. which in turn makes the house blow out like a bomb.
edit: they work well for straight strong winds like hurricanes but tornados are twirling winds coming from all sides like a blender
Masonry has been tested and they do fail requirements for tornado resistance unless they are fully grouted & reinforced. That could be a factor.
Good point about the size & scale of a shelter as opposed to a house though. Geometry is a huge factor to determine how the wind pressure acts on a building.
How about a concrete core structure that would withstand tornadoes and would contain bedrooms and kitchen, bathroom, laundry, all the must haves. Then construct the less necessary spaces around it with traditional wood. It the structure is hit, it's possible the storage and accessory spaces may be damaged but you could comfortably live in the concrete structure until the other structures are replaced. Of course, you could beef the stick framed areas up to try to withstand higher winds etc. but this would allow for continuous use of the property in a tornado event.
that's interesting! but you didnt make it very clear where the metal goes. if you can specify 12-14ga steel as exterior cladding/roofing, then it could theoretically work, though be quite expensive, possibly more expensive than rolling the dice with the low probability of tornado hitting you. steel siding and roofing is usually 26-31ga steel.
you could probably find a cheaper alternative with different geometry (at a minimum, corrugated metal and foam may have crush/piercing resistances that are much higher than flat materials).
i would actually probably want to see a kevlar-like housewrap in this situation. it's very likely that two layers of standard steel stucco netting would to the job as well.
Yeah the Texas Tech literature is great. I feel like money would be better spent on an in-house tornado shelter given the rarity that any particular house will experience tornado-level winds.
I lived in southern Minnesota in the early mid-1970s. The area had a lot of 'tornado magnets.' I mean: trailer parks. Since they often tumbled about in a weather event, the state legislature mandated that they be secured in place with a pair of tornado anchors: 2 long screw anchors wound 3 or more feet into the dirt on ether side and straps that passed over the roof, attached to the anchors. Typically, there would be two or three of these anchor-strap devices on a house-sized mobile home, one at each end and one in the middle if it were a long house.
A couple years later they looked at the data and found that mobile homes now suffered MORE damage than before. The cause was a failure to flex in the wind. The anchors held them rigidly in place while the wind shredded them.
Clearly, current permanent dwellings are build to resist gravity. Survival in a tornado would mean they should resist tension/uplift. Holding the roofs more securely in place with straps is just bonus. So while California homes need to resist racking from earthquakes, houses in tornado prone areas need to resist uplift. Straps that run from the top plate to the foundation would do the job. As long as the corners are secured to resist racking. That and being built more substantially than a mobile home.
In fact, those connectors you showed at the end are just a another day on the job in Southern California. They even have small air-powered nail drivers to install them, rather than one guy crawling around all day, tacking them in place with joist hanger nails.
Thanks for sharing your experience. I agree that the types of connections used are extremely important and as I kept digging, I realized connections could be a whole other video. You’ve made me want to take a deeper look at the efforts back in the 70s. Thanks again!
@@JthaEngineer In Iowa in the 1970s, we used roofing nails for joist hangars. When I moved to SoCal I learned about a whole new realm of techniques and materials. We had one guy whose job was to nail on A35 clips - what were called 'Ticos' - EVERYWHERE, especially where the joist and rafter blocking meets the plates.
Slowly over the next 20 years, more and more clips came in. Rafter to top plate. Straps across headers even if they already had sheeting. 3' straps across the ridge on the roof. Straps around the corners of the top plates and box sills.
All of these require special nails, Tico nails. They are only 1.5" but the shank is thick like a 16d nail. A very far cry from the roofing nails we used in Iowa. Now they have screw fasteners in lieu of HD brackets and steel boxes to stiffen garage walls on either side of the door.
Keep making these vids, man. They are excellent real-world lessons that guys in the field can put to use straight away.
You missed the boat by not including concrete/Styrofoam hybrid blocks such as Miracle blocks, EZ blocks, etc. The ones built north of Houston have easily handled hurricanes, tornados, flooding, while being highly energy efficient and lower cost to build than wood framing.
You are brilliant. Building with reinforced concrete block should not be that much more expensive. YOU could offer the expertise to any gc to do it right. The GC just needs to hire 4 min wage workers with green cards, as I assume like in my area, the chance of finding anyone born in the USA willing to work concrete for even 2x min wage is non existant. I can't even find them to carry sacks for cash. Any rate. you need rebar sticking out of footings a few feet up through CMU cells, thats an upgrade to foundation but any foundation gc can handle the extra rebar work no problem or you shouldn't trust any work to them. After that, you teach the min wage workers how to tie rebars together and instruct them to put in 2x as many ties as needed and photograph each one. There's the way you ensure quality. It's a secret, shhhhh. Then teach them to shovel concrete into cells and rodding it. The mason should know how to install horizontal reinforcement so all you need do is tell him to put it in EVERY course and provide him 2 of those min wage workers to carry the extra horizontal reinforcing, align it with all the rebar sticking up and slide it down over it. Heh, that does take time, time is money. Another worker will be needed to lift the CMU up over the tops of the rebars and hold it while the mason does the mortar work. The fourth min wage worker is running the mixer mixing concrete all day. The solid steel sheet is something I didn't know. I have to look up sometime if multiple layers of expanded mesh might work too, also doing two 2x4 walls with offest studs to cut energy transfer. Like Siding, air barrier, expanded lath, plywood, expanded lath, 2x4, rock wool, expanded lath, air barrier, plywood, expanded lath, fiberglass insulation, wiring, conduit, ducts, etc., and the drywall. It's a lot more layers, thus a lot more labor, but it's pretty much unskillied labor, light materials. I'd have to consider screwing through 12 ga steel sheet to be a specialty skill and require specialty fasteners. The siding metal interface might also create a good deal of moisture buildup one way in summer, the other in winter, requiring a really air tight wall assembly to keep moisture vapor out of wall cavity, and with electrical boxes etc set into wall, it's just not going to every be air tight. Hope maybe just one person finds this and it helps them. I live outside of tornado country.
So what were the 3 materials?
Doesn’t a 4x8 12g sheet weigh like 100lbs and cost a quite a bit of money?
I wonder what impact resistant plastics could be used. Might be lighter/cheaper. Likely much thicker for same resistance and need protection from UV (would want siding over it as well).
Meanwhile outhere where I live builders be sheating roofs with 3/8 aspen.
Really?! That sounds problematic…
@@JthaEngineer yes and we never instal blocking between truss and we only toe nail the trusses to the top plate. Never see anyone use any type of structural screws or metal connectors apart from joist hangers. Educating myself online is making me realize how low the quality of our houses are here.
Instead of building the whole house like a safe room, couldn't you just build a safe room as a usable space and build the rest so that it doesn't blow away, but you just patch holes? You'll be replacing windows anyway. So build it for the wind forces, not debris per se.
That red area has to deal with a lot of water and hail that comes with the thunderstorms that create the tornadoes, but at the same time it's hot and dry in the summer, so maybe v2 can be fire resistant too? Use metal roofs, fiber cement siding and Rockwool insulation.
Because temperatures can be extreme, maybe also make it energy efficient so you can survive a few days without power. Oh, and make it affordable 😂
OK, but this falls short. It's interesting, but continue the exploration. We build in California earthquake country, & I'm moving to the Florida coast with high humidity and hurricanes. Our projects are Net Zero Energy, Passiv Haus, kind of high-performance stuff. With what you propose, what's the energy profile here? Many of these structural systems kill energy performance. Look deeper. Solve this as a "system", not just a lowly turf war. Don't kill one in favor of another. A house is a system. Water condenses on steel surfaces. Make sure these ideas don't kill any of the 3 barriers (water, air, thermal). Otherwise, it's just jaw-boning.
After-all, if it doesn't last, it doesn't matter.
In norway we build houses with alot of reinforcwd concrete
What if instead of traditional studs and plywood sheathing you used cross laminated timber with exterior rigid insulation with metal siding then used extremely robust brackets to mount the panels to each other? I’m not an expert at all and don’t live in an area where I have to worry about high wind that often but it seems like it would be pretty resilient compared to a traditionally framed house.
I’m not sure if CLT has been tested against a projectile test but I could see that working
I think it would be cheaper to move to a nicer climate. With that being said would you consider wire reinforce stucco?😎
You know what…. I kind of agree with you lol. As far as stucco, I probably wouldn’t.
I need a building just to hold legacy cables, cords and connectors.
Hello, this sounds I guess sort of simplistic or unrealistic, but why can't the house have a roof that extends down to the ground in case of high winds or have the home partially descend into the ground in case a tornado is coming? Is this totally impractical? I wonder
We need someone to invent concrete paint!!
He forgot duck tape 😂
Ok so homes in Florida r made of concrete we had a hurricane with winds of 130 mph and the wall did not fall. So I don't know if a tornado would be any different I don't know that one, I've never been thru a tornado.
What about just having a room in the house that is tornado resistant instead of the whole house
@6:10 I would love to help build a model for you to test this.
Modeling will require "Non Dimensionalization" and without removing the unscalable dimensions you would only be playing with model toys.
Really I could use the practice.
Don’t forget Hurricane strapping - goes over the roof and has strong connects to the foundation. Required in Florida I believe. If you build to at least places that have the worst hurricanes and the worst tornados - you have a better chance. Now - some of the numbers I have seen and heard - it is more money up front but not that much. It’s my understanding you are talking $5-15,000 more depending on how over these top you go. Right now 2022 anything is ridiculously expensive. I would imagine if you live where much is standard code because of the billions of dollars of damage overall per event - it would be less than building somewhere that never sees a hurricane or rarely tornado. They just don’t build to that level so it’s just beyond understanding and see going to cost you big-time.
Look at the building codes of those seriously impacted multiple times over the last 10 years like Texas, Florida, Nebraska, etc. etc. They may help somewhat in what you want. For example in Florida’s high impact of by the ocean type facilities ie hurricane resistant windows and doors. They are heavy and feel like commercial but they must have proper framing. Doesn’t do any good to have this triple panel high impact glass with a 2x4 or 2x6 wood stud. The framework has to standup.
The other thing with tornado proof homes - they need to get the pressure issue right. The home might stand up to the winds but it’s the pressure of tornado that blows it apart.
The attached garage is a huge culprit in tornado damaged homes. The failure of the weakest point is the garage door, once it goes the wind has the ability to lift up on the roof and once the roof goes the structure is too far compromised and it collapses!
Let’s get into under ground bunker
Ive seen brick and concrete buildings completely leveled out right down to the foundation. It’s not just about impact resistance. It’s about Wind Shear as well.
Wood has an extremely high tensile strength but the way houses are built it will never be used because of nails attaching everything together.
You need metal brackets with bolts going though each 2x4 2x6 or 2x8 and the bottom of all that needs to have bolts going into concreate not nailed into a pressure treated 2x6.
I would rather have a wood house built for tornados than a concrete.
Yes, failure points are almost always at the connections with wood. Nails are easy and fast but limit the structures strength
Just make them out of masonry and concrete like every other tornado prone country in Asia.
This is how they build houses in Mexico
#PayOnceAndCryAboutThePriceOnlyOnce
Missiles are not ballistic the boards are
windows....
Just use ICF, guys. Lumber isn’t solution for tornado. Here, in Europe, we have home made from bricks and concrete. No problems for hundreds of years. Yes, lumber is more sustenable, but we build to last a looooong no time. Quality comes with a cost, that’s reality.
Yep more wood.. Better think of using more bricks and concrete in the future. Build it like an turtle shell design. Learn from the mod car in chasing tornadoes series.
well...seems a "tornado-resistant" ROOM would be, you know...AFFORDABLE. And, better-suited to Designs that most-folks would actually PAY-for to Own. Say...Jay, do YOU live in such a structure, hmmmmmmm??? :-)))
Useless, you can just build a reinforced concrete (RC) house. and that's all.
Or you could just use all level 3 build materials.
Also, concrete ain't shit. Underground bunkers are your only option.
ICFs would be quicker, cheaper, and more practical.