| reply to IowaCowboy
Re: Tornados & House Structure Question.. I don't understand why they don't use steel roll-up shutters over windows in hurricane areas. It seems like it would pay for itself in time and money the first time you would normally put plywood over all your windows.
But then what would the news channels show to hype their hurricane coverage? People pushing a button and the shutters rolling down? |
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 panth1The Coyote
join:2000-12-11
Boca Raton, FL | Lots of houses and businesses have roll up shutters in Florida.
The main problem is they cost a lot more than the alternative wood or steel panels. Some people like the easy of closing them while others may balk at the look of tracks and a big box at the top of the window/door. Some opening may also not allow for a installation and electric runs.
Impact glass is also becoming more popular in new construction. |
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 49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | reply to John Galt
said by John Galt:For my projects I recommend dual mat #6 rebar on 12" centers with a 6" horz/vert offset per mat; walls, ceiling and floor, and a layer each of expanded metal on the facing sides of the rebar prior to the pour. Weld every other rod crossing and overlap.
Put that into a 10" thick 4,000 psi microfiber admixture concrete wall and you've got protection above ground. Sounds like some of the L-4 repeater buildings AT&T constructed during the cold war that where designed to withstand blast pressures up to 50 PSI.
Wayne
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| reply to Rob
A cement/concrete/cinder block house where the corners are just interlocked together like it seems the house in the picture was built won't cut it. Here in Puerto Rico most homes are built using concrete. Either by using a few parallel poured load-bearing walls with a poured slab roof and concrete block partitions, or the entire house built using blocks but all corners or places where wall meet are reinfored concrete columns. The entire thing has a poured reinforced concrete beam on the top portion of the walls (above the blocks and columns) and then on top of that the poured concrete slab. The finished structure is basically monolythic.
They work wonders for hurricanes but I wonder how they would fare in a tornado. I know the windows would not hold in a tornado but the structure would remain. |
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 mityfowlPremium
join:2000-11-06
Dallas, TX | said by printscreen:A cement/concrete/cinder block house where the corners are just interlocked together like it seems the house in the picture was built won't cut it. Here in Puerto Rico most homes are built using concrete. Either by using a few parallel poured load-bearing walls with a poured slab roof and concrete block partitions, or the entire house built using blocks but all corners or places where wall meet are reinfored concrete columns. The entire thing has a poured reinforced concrete beam on the top portion of the walls (above the blocks and columns) and then on top of that the poured concrete slab. The finished structure is basically monolythic.
They work wonders for hurricanes but I wonder how they would fare in a tornado. I know the windows would not hold in a tornado but the structure would remain.
I wonder which of my x wifes would like to live there? |
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mityfowlPremium
join:2000-11-06
Dallas, TX | reply to Rob
My dad told us "its time to move NOW"
we did. |
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 RobIn Deo speramus.Premium
join:2001-08-25
Kendall, FL
kudos:3 | reply to Rob
What i was trying to get at, is if the cinder block structure could withstand a tornado (even if the room is torn off and the house is gutted), wouldn't recovery be a little faster since the structure of the home is still there?
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mityfowlPremium
join:2000-11-06
Dallas, TX | said by Rob:What i was trying to get at, is if the cinder block structure could withstand a tornado (even if the room is torn off and the house is gutted), wouldn't recovery be a little faster since the structure of the home is still there?
Think of getting hit with 500 lbs dumb bombs |
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| reply to Rob
said by Rob:What i was trying to get at, is if the cinder block structure could withstand a tornado (even if the room is torn off and the house is gutted), wouldn't recovery be a little faster since the structure of the home is still there?
Replacing the roof and the windows should be faster and cheaper than replacing the whole thing, that's for sure.
However, I think even woodframe houses could be built to be much stronger with some simple enhancements. I do not know the building standards in Florida and other places in the south, but here pretty much everything is nailed together with a nailgun, and with enough force, it's not too difficult to pull those nails out. However, if screws were used instead, they would require a significantly bigger force. In addition glue could also be added for some additional strength and rigidity. Of course they would add quite a bit of labor cost, and make construction much slower. (Personally, I use screws as much as I can, but usually don't bother with glue since hurricanes and tornadoes are very rare around here)
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 marigoldsGainfully employed, finallyPremium,MVM
join:2002-05-13
Saint Louis, MO
kudos:2 | reply to Rob
said by Rob:What i was trying to get at, is if the cinder block structure could withstand a tornado (even if the room is torn off and the house is gutted), wouldn't recovery be a little faster since the structure of the home is still there?
Can the cinder block walls be reused once the roof is torn off and the house is gutted? If a full demolition is required before rebuild, then you have to deal with hauling off cinder blocks instead of wood.
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| said by marigolds:Can the cinder block walls be reused once the roof is torn off and the house is gutted? If a full demolition is required before rebuild, then you have to deal with hauling off cinder blocks instead of wood.
Why not? |
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| reply to mityfowl
said by mityfowl:I wonder which of my x wifes would like to live there?
Don't get it. |
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mityfowlPremium
join:2000-11-06
Dallas, TX | said by printscreen:said by mityfowl:I wonder which of my x wifes would like to live there?
Don't get it. No matter what you do an x wife won't be happy. |
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| reply to panth1
said by panth1:Lots of houses and businesses have roll up shutters in Florida.
The main problem is they cost a lot more than the alternative wood or steel panels. Some people like the easy of closing them while others may balk at the look of tracks and a big box at the top of the window/door. Some opening may also not allow for a installation and electric runs. I visited a town in France where roll-up shutters are required by code (although they're vinyl, not steel). The mechanism is installed entirely within the wall of the structure and you can't even tell it's there. Push one button, and all the shutters roll down in seconds. They even have big ones that cover sliding doors, and you can't tell they're there.
The houses in France are made using some type of building block. They love them. They can't burn. They laugh at us for the number of house fires we have.
Every window and glass door in the above photos is protected by a roll-up shutter. You can't even see them. And the house is constructed of a material which cannot burn. |
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iknowPremium
join:2012-03-25 | reply to aurgathor
said by aurgathor:said by Rob:What i was trying to get at, is if the cinder block structure could withstand a tornado (even if the room is torn off and the house is gutted), wouldn't recovery be a little faster since the structure of the home is still there?
Replacing the roof and the windows should be faster and cheaper than replacing the whole thing, that's for sure. However, I think even woodframe houses could be built to be much stronger with some simple enhancements. I do not know the building standards in Florida and other places in the south, but here pretty much everything is nailed together with a nailgun, and with enough force, it's not too difficult to pull those nails out. However, if screws were used instead, they would require a significantly bigger force. In addition glue could also be added for some additional strength and rigidity. Of course they would add quite a bit of labor cost, and make construction much slower. (Personally, I use screws as much as I can, but usually don't bother with glue since hurricanes and tornadoes are very rare around here) screws can't be used instead of nails because they aren't rated for shear strength, they are hardened, and can snap, where a nail will bend. they CAN be used in addition to the required amount of nails, though. |
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marigoldsGainfully employed, finallyPremium,MVM
join:2002-05-13
Saint Louis, MO
kudos:2 | reply to printscreen
said by printscreen:said by marigolds:Can the cinder block walls be reused once the roof is torn off and the house is gutted? If a full demolition is required before rebuild, then you have to deal with hauling off cinder blocks instead of wood.
Why not? Well, at a certain level of placard, mandatory demotion comes into play. But after doing some research, missing roof and interior walls gutted is only a mandatory yellow placard at the highest level.
As long as no more than 2 rooms are destroyed, it could still avoid red placard and potential mandatory demolition (red by itself is not a mandatory demolition, but some cities will automatically issue a demolition order on a red placard house).
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| reply to iknow
said by iknow:screws can't be used instead of nails because they aren't rated for shear strength, they are hardened, and can snap, where a nail will bend. they CAN be used in addition to the required amount of nails, though.
References?
The screws I normally use for framing (#9 x 3.5") has a somewhat higher diameter than the comparable nails, and if they're subjected to a force sufficient to snap them, then I think all bets are off and an equivalent nailed structure would fail earlier than that.
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| reply to marigolds
said by marigolds:Well, at a certain level of placard, mandatory demotion comes into play. But after doing some research, missing roof and interior walls gutted is only a mandatory yellow placard at the highest level.
As long as no more than 2 rooms are destroyed, it could still avoid red placard and potential mandatory demolition (red by itself is not a mandatory demolition, but some cities will automatically issue a demolition order on a red placard house).
I am not familiar with the placard thing you mention but I was based on that if the block structure was not damaged and its structural integrity was kept why not reuse the same structure with a new roof and interior walls? A house could be damaged with a missing or badly destroyed roof but still have the exterior walls intact. |
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| reply to iknow
Based on my own testing, it takes about 25X the force to pull screws out, versus nails of the same size. I put larger screws about an inch apart on the roofing, ext walls, etc. Use lag bolts to hold structural members together, with the addition of screws in between for extra bonding. I can assure anyone that the wood will shred apart before the screws give way.
I see new construction using large staples now and flakeboard (OSB) for sheathing. Houses in the 60s used to use Cleotite on 2x4 studs. My first house was nearly destroyed in an F1 tornado in the early 60s because of this shoddy contractor construction. When I built my own house, I decided to build to withstand a 30KT blast at 1 mile, or 300MPH gusts. Contractor built homes are dangerous. I don't feel secure in them. I can kick a hole in the wall easily. How would that keep a burglar out, much less a tornado? |
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marigoldsGainfully employed, finallyPremium,MVM
join:2002-05-13
Saint Louis, MO
kudos:2 | reply to printscreen
said by printscreen:said by marigolds:Well, at a certain level of placard, mandatory demotion comes into play. But after doing some research, missing roof and interior walls gutted is only a mandatory yellow placard at the highest level.
As long as no more than 2 rooms are destroyed, it could still avoid red placard and potential mandatory demolition (red by itself is not a mandatory demolition, but some cities will automatically issue a demolition order on a red placard house).
I am not familiar with the placard thing you mention but I was based on that if the block structure was not damaged and its structural integrity was kept why not reuse the same structure with a new roof and interior walls? A house could be damaged with a missing or badly destroyed roof but still have the exterior walls intact. In a disaster, a damaged house receives a placard ranging from green to red. Green are safe to occupy. Yellow can be entered but have restrictions on occupancy. Red cannot be entered except for emergency operations. The rule of thumb is green can be repaired in 30 days, yellow can be repaired but in more than 30 days, red is not economically feasible to repair.
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