# 30 story wood high rise building



## Coug Dad (Mar 8, 2011)

An interesting article on proposed wood high rises.  Should raise some interesting code issues.

http://www.winnipegfreepress.com/canada/bc-architect-touts-plans-for-first-timber-skyscraper-117569813.html


----------



## fatboy (Mar 8, 2011)

Holy crap.......say it ain't so........


----------



## FM William Burns (Mar 8, 2011)

Shaking head from side to side while flubbering the lips :0


----------



## permitguy (Mar 8, 2011)

Marshmallows and hot dogs are on me.  Bring your own cooking stick.


----------



## texasbo (Mar 8, 2011)

Christ.

Go for it, Canada.

Just keep it at least 30 stories north of the border.


----------



## texasbo (Mar 8, 2011)

permitguy said:
			
		

> Marshmallows and hot dogs are on me.  Bring your own cooking stick.


Cooking sticks are apparently supplied by the host. Just be careful to pick it up by the end that isn't cooking, if there is one.


----------



## fatboy (Mar 8, 2011)

http://www.structuremag.org/Archives/2006-6/D-Fex-Hi-Rise-wood-frame-const-June-06.pdf


----------



## brudgers (Mar 8, 2011)

Given the amount of technology already required in a traditional non-combustible tall building, it seems plausible with appropriate fire protection measures.  Keep in mind that when it comes to tall buildings, we are already talking about high performance systems.


----------



## texasbo (Mar 8, 2011)

Brudgers, most contractors can't build a complying Fire Wall in a two-story apartment complex in three tries.

Getting the equivalent of Type I protection for a 30 story wood structure might be possible on paper, but so is time travel.


----------



## dhengr (Mar 8, 2011)

And, they are working on high performance trees right now.  20ksi tension and compressive strength, modulus of elasticity of at least 30000ksi, non shrink.  And, to get extra LEED points they want the trees to grow to harvesting size in two years.  Just think of all the carbon they can sequester.  I wonder who financed this study?  It’ll be interesting reading to see how they tackle some of the real high rise problems.


----------



## FredK (Mar 8, 2011)

All I know is that I'm wouldn't be checking nail spacing for shear.  Can't get spacing right one story homes as it is now.  But then anything is possible.


----------



## Architect1281 (Mar 8, 2011)

Ah to be a termite in Vancouver if Only I had a jacket


----------



## texasbo (Mar 8, 2011)

That's easy; they'll throw some of that "high impact sheetrock" at the exit enclosures and call the whole sh!t'n thing not only green, but bombproof.

Anyone heard of Angry Birds?

Oh, and we used to have high performance forests that produced elements that exceeded the properties you described. They were forests that grew all along the Monongahela River in Western Pennsylvania.



			
				dhengr said:
			
		

> And, they are working on high performance trees right now.  20ksi tension and compressive strength, modulus of elasticity of at least 30000ksi, non shrink.  And, to get extra LEED points they want the trees to grow to harvesting size in two years.  Just think of all the carbon they can sequester.  I wonder who financed this study?  It’ll be interesting reading to see how they tackle some of the real high rise problems.


----------



## High Desert (Mar 9, 2011)

Don't worry. after all the wood shrinkage it'll only be a 15-story building.


----------



## FM William Burns (Mar 9, 2011)

Now that is real funny.....good one!


----------



## peach (Mar 9, 2011)

some Code Official somewhere is buying this?  having said that, I've seen 100 year old 11 story wood buildings.. brick exteriors, so they can be sneaky to classify...


----------



## Yikes (Mar 10, 2011)

I think I saw a 30 story tree once... in "Avatar".


----------



## sergoodo (Mar 10, 2011)

"30 storey" I can't find "storey" definition in the IBC...prolly gonna be built by Hobbits, Canadian Hobbits.


----------



## TJacobs (Mar 11, 2011)

Too bad Irwin Allen isn't around to make Towering Inferno 2.


----------



## Coug Dad (Mar 11, 2011)

sergoodo

I think I saw a "storey" once when I went to the theatre at the civic centre - eh!


----------



## Outside (Mar 23, 2011)

Do not get too excited!  The article only talks about conceptual possibility.  The devil is in the details.


----------



## Coug Dad (Mar 23, 2011)

It's Canada eh?  Anything is possible.  They allow a owner / design team to hire a consultant to perform the role of the building department and have the permit issued.


----------



## MarkRandall (Mar 23, 2011)

Who knows, maybe they can surprise us all with a cost effective green solution. It sounds too theoretical to me, though. On a side note, the Tacoma dome roof structure is all wood and IMHO a very nice space to be in. I think it was the first of it's kind and I'm not sure it's been duplicated since. There's also a wood roof truss dome in Moscow Id (The Kibbie Dome). Those don't really compare to a 30 story building, but I'm sure there were plenty of skeptics on both those projects.


----------



## Coug Dad (Mar 23, 2011)

The Tacoma Dome is the world's largest wood dome.  Mark, are you Vancouver BC or WA?


----------



## MarkRandall (Mar 23, 2011)

I'm in Vancouver, WA


----------



## BSSTG (Mar 24, 2011)

Greetings

sounds like we may have a remake of "Towering Inferno" pdq

BS


----------



## FyrBldgGuy (Mar 24, 2011)

At least the scaffolding will be stronger than the building.

I can see already the steel workers picketing the construction site.


----------



## Coug Dad (Mar 28, 2011)

More on the all wood high rise.  This article addresses safety and finding a city to allow it.

http://www.themarknews.com/articles/4493-are-wooden-skyscrapers-in-our-future


----------



## conarb (May 4, 2011)

So much for that idea.


----------



## FM William Burns (May 5, 2011)

Hummmmmmmmmm


----------



## brudgers (May 5, 2011)

conarb said:
			
		

> So much for that idea.


Large wood frame buildings under construction have the same issues - the height is pretty much irrelevant.

This one burned down the fire department across the street.

http://www.poynter.org/uncategorized/10629/forklift-accident-sparks-massive-fire-in-ybor-city/


----------



## jannypan (May 16, 2011)

Holy crap.......say it ain't so........


----------



## Coug Dad (May 17, 2011)

Welcome to the board, Jannypan.


----------



## RickAstoria (Aug 28, 2011)

I'm coming to this topic a tad late but it is doable to make a wood-frame building that meets Type I-A "non-combustable" assembly.

In other words, if the Built-up beams 7 columns are encapsulated in CMUs, bricks or other fire-resistant construction in such a manner

that literally prevent fire-spread into the wooden frame-work. Much the same way you deal with encapsulating steel frame which

would collapse under similar fire condition by melting instead of combusting into flame which isn't really helpful. Massive built-up and

Glu-lam would would have similar treatment as Heavy Timber in charring effect which helps protect the remaining members if they

are oversized. I do believe it is doable but it needs to be an assembly of fire-protection that meets or exceeds the fire-rating

requirements as well as be able to perform structurally for the load wait. If it were me, the fire-protection "shell" would need to be

like brick veneer and be quasi-load / non-load bearing in nature. The Timber (so to speak) needs to be sized to handle the load. Just

as you can have concrete or masonry encased steel frame where the steel is no more fire-resistant than the wood would be. So

why not if the timber themselves used in the primary structural frame that be encapsulated would be Heavy timber that is fire-resistant

to begin with but that should not matter any more then the shell that protects the timber.

In essence, such protective shell should not allow for any exposure zone. In essence, all sides would be protected by the required

level of fire-protective covering. Therefore the shell must meet the fire-rating.


----------



## RickAstoria (Aug 28, 2011)

texasbo said:
			
		

> Brudgers, most contractors can't build a complying Fire Wall in a two-story apartment complex in three tries. Getting the equivalent of Type I protection for a 30 story wood structure might be possible on paper, but so is time travel.


You say they can't build CMU walls or encapsulate the the wooden beams and columns and such with refractory clay/ceramic bricks

or CMUs or whatever else used for fire-protection meeting the fire-rating. I would require that the such timber/wooden frame would

include the fire rated protective shell. The timber column assembly for a Type 1 construction should have a fire-rated shell that

become part of the assembly and meet the requirements.

Such is easy enough to do. If the contractor can't do the job then he doesn't get the contract. PERIOD.


----------



## brudgers (Aug 29, 2011)

RickAstoria said:
			
		

> I'm coming to this topic a tad late but it is doable to make a wood-frame building that meets Type I-A "non-combustable" assembly. .


Late and wrong.


----------



## RickAstoria (Aug 29, 2011)

brudgers said:
			
		

> Late and wrong.


It is doable. Steel and Wood has a fire-rating of basically 0. Steel melts and becomes a collapse hazard just as wood would be burning.

It would be about equal for as far as anyone is concern. For Type I-A really just needs a complete fire-resistant assemble around the

combustable ( in the case of steel - bend & melt ) material. Hence why steel is coated with fire-rated coating. Just need to meet 3-hr

fire rating for the structural columns and beams. In addition, you make sure you have all the fire-block and draftstops and such that

the wood or steel is not exposed. Yes, there is some exceptions already in the code but wood is not really more prone to failure from

fire than steel. Steel will melt to liquid state while wood would char to ashes. In the end, it doesn't matter. Unprotected steel and

wood would be about zip in fire-resistance. In a Type I construction, I would argue that for fire-protection rating, unprotected steel

and wood be treated as 0-Hr. So the fire-protective shell should be considered part of the assembly. Just as you can coat steel or

wrap the steel in a shell of concrete, or Type-X drywall (3 to 4 layers thick) or some other assembly. The assembly as a whole

should be considered for determination as whether the Building Element (as an assembly) meets the non-combustability level for the

fire-rating. I think a wood structure protected in the same protective "shell" would be similarly performing to that of a steel frame

structure which would not meet the Type I-A unless it meets the fire-rating standard for the building element.

I know there is more nuances of exceptions and Hour rating reduction exceptions but I am not going there as that become verbose

more than I would think would be necessary.

If one uses a glu-lam column in lieu of an W-section steel column, it should be protected in the same protection shell as would a

steel W-section would have to meet the fire rating for the Primary Structural Frame - Building Element. All cases that I am aware of

it is 3 hours. Exposed steel does not have 3-hour rating and will collapse in a fire, easily within an hour.

It just requires a shell. The hardest challenge that I can think of is load-bearing capacity and possibly shear resistance.

A skyscraper would put considerable load conditions. I do believe it is doable but I would expect it to be in a protected assembly

similar to that used to protect Steel columns and beams. It is possible so it could possibly work. Steel was after all the metal

analogy to wood frame structure.


----------



## righter101 (Aug 29, 2011)

Finally, we can see the use of a wooden moment frame.

I've only heard about these.

I read more about this building.  It is going to be a unicorn research center, atleast on the first 2 floors.


----------



## RickAstoria (Aug 29, 2011)

In reply to righter101,

I do believe it is potentially possible to design a building using the wooden framing. Many of the common fire-protection

methods for steel frame can also be used for protect a wood column. What it takes to burn glulam, large built-ups or

Heavy Timber solid hewn to crisp would melt steel to point of collapse. In either case, necessary fire-protection would

be necessary to provide the same level of fire-protective assembly to not combust to comparable level as would be for

other non-combustable elements used in Type I structures.

There are other challenging issues to bear in mind. Fire-protection is easy enough to maintain. Wood beams can be

made with comparable performance to many of their steel counterparts. The challenge to supertall maybe doable with

structures primarily of wooden frame with reinforced concrete stair wells and elevator shafts where needed and ballistic

protection.


----------



## brudgers (Aug 29, 2011)

RickAstoria said:
			
		

> It is doable. Steel and Wood has a fire-rating of basically 0. Steel melts and becomes a collapse hazard just as wood would be burning. It would be about equal for as far as anyone is concern. For Type I-A really just needs a complete fire-resistant assemble around the  combustable ( in the case of steel - bend & melt ) material. Hence why steel is coated with fire-rated coating. Just need to meet 3-hr fire rating for the structural columns and beams. In addition, you make sure you have all the fire-block and draftstops and such that  the wood or steel is not exposed. Yes, there is some exceptions already in the code but wood is not really more prone to failure from  fire than steel. Steel will melt to liquid state while wood would char to ashes. In the end, it doesn't matter. Unprotected steel and  wood would be about zip in fire-resistance. In a Type I construction, I would argue that for fire-protection rating, unprotected steel  and wood be treated as 0-Hr. So the fire-protective shell should be considered part of the assembly. Just as you can coat steel or  wrap the steel in a shell of concrete, or Type-X drywall (3 to 4 layers thick) or some other assembly. The assembly as a whole  should be considered for determination as whether the Building Element (as an assembly) meets the non-combustability level for the fire-rating. I think a wood structure protected in the same protective "shell" would be similarly performing to that of a steel frame  structure which would not meet the Type I-A unless it meets the fire-rating standard for the building element.  I know there is more nuances of exceptions and Hour rating reduction exceptions but I am not going there as that become verbose  more than I would think would be necessary.   If one uses a glu-lam column in lieu of an W-section steel column, it should be protected in the same protection shell as would a  steel W-section would have to meet the fire rating for the Primary Structural Frame - Building Element. All cases that I am aware of it is 3 hours. Exposed steel does not have 3-hour rating and will collapse in a fire, easily within an hour.   It just requires a shell. The hardest challenge that I can think of is load-bearing capacity and possibly shear resistance.   A skyscraper would put considerable load conditions. I do believe it is doable but I would expect it to be in a protected assembly similar to that used to protect Steel columns and beams. It is possible so it could possibly work. Steel was after all the metal  analogy to wood frame structure.


  Rick, no matter how many seemingly relevant terms you dump into your post it is still wrong.


----------



## RickAstoria (Aug 30, 2011)

I do believe it is potentially possible to design a building using the wooden framing. Many of the common fire-protection

methods for steel frame can also be used for protect a wood column. What it takes to burn glulam, large built-ups or

Heavy Timber solid hewn to crisp would melt steel to point of collapse. In either case, necessary fire-protection would

be necessary to provide the same level of fire-protective assembly to not combust to comparable level as would be for

other non-combustable elements used in Type I structures.

There are other challenging issues to bear in mind. Fire-protection is easy enough to maintain. Wood beams can be

made with comparable performance to many of their steel counterparts. The challenge to supertall maybe doable with

structures primarily of wooden frame with reinforced concrete stair wells and elevator shafts where needed and ballistic

protection.


----------



## RickAstoria (Aug 30, 2011)

brudgers said:
			
		

> Rick, no matter how many seemingly relevant terms you dump into your post it is still wrong.


It is simple to protect wood from fire. Ever heard of refractory brick. There is a few classified material that can

be used that even after being engulfed fire as hot as the surface of the sun, it won't transfer the heat through.

There is NO reason that a high rise / skyscraper building made of wood construction can't be built if provided by

a 3-hour rated protective covering over structural columns / beams, ceilings, floor decking and wall covering.

If you want a test proof, I'll be more than willing to encapsulate a 6x6 post 1-ft. high with fire bricks encapsulating

the around the wood with a 2" to 3" gap. (other then the metal ties to tie the fire-brick veneer. It just need the

gap to minimize heat transfer. Of course the 6x6 and the brick would be mounted onto a concrete  block pad.

It would be heavy due to the concrete. Then throw it in a kiln that is capable of 2000-3000 degrees such as an

Anagama kiln or a PMC Kiln. The standard temperature test is something like....1800-2200 degrees F. Basically, a kiln.

If the assembly is kiln tested to 3-hours then it would have the fire-rating as an assembly of "masonry encased

timber frame". It isn't rocket science. It is a matter of an "assembly". The point is the structural column assembly

is more then just a wood post but a "masonry-encased wood post". It is easy to deal with. Steel loses about half its

strength in the 650 degrees Celsius range (which is around 1200 degrees F.)

It is all about life-safety. If it is hot enough to burn through the fire-protected layer, I would say that the condition

would be hot enough to melt structural steel used in buildings - at least most of the typical alloys used. ( In the

matters of minutes the steel would begin to fail and in minutes it would become a melting situation ).

So think about it. The protective layer is what is important. If you can use steel, you can use wood for the very

purpose in similar protective covering used to protect the steel can be used to protect the wood.


----------



## brudgers (Aug 30, 2011)

RickAstoria said:
			
		

> It is simple to protect wood from fire. Ever heard of refractory brick. There is a few classified material that can  be used that even after being engulfed fire as hot as the surface of the sun, it won't transfer the heat through.  There is NO reason that a high rise / skyscraper building made of wood construction can't be built if provided by a 3-hour rated protective covering over structural columns / beams, ceilings, floor decking and wall covering.   If you want a test proof, I'll be more than willing to encapsulate a 6x6 post 1-ft. high with fire bricks encapsulating the around the wood with a 2" to 3" gap. (other then the metal ties to tie the fire-brick veneer. It just need the gap to minimize heat transfer. Of course the 6x6 and the brick would be mounted onto a concrete  block pad.  It would be heavy due to the concrete. Then throw it in a kiln that is capable of 2000-3000 degrees such as an  Anagama kiln or a PMC Kiln. The standard temperature test is something like....1800-2200 degrees F. Basically, a kiln.  If the assembly is kiln tested to 3-hours then it would have the fire-rating as an assembly of "masonry encased  timber frame". It isn't rocket science. It is a matter of an "assembly". The point is the structural column assembly is more then just a wood post but a "masonry-encased wood post". It is easy to deal with. Steel loses about half its strength in the 650 degrees Celsius range (which is around 1200 degrees F.)  It is all about life-safety. If it is hot enough to burn through the fire-protected layer, I would say that the condition  would be hot enough to melt structural steel used in buildings - at least most of the typical alloys used. ( In the matters of minutes the steel would begin to fail and in minutes it would become a melting situation ).  So think about it. The protective layer is what is important. If you can use steel, you can use wood for the very  purpose in similar protective covering used to protect the steel can be used to protect the wood.


   Rick, Open your code book and review chapters 3, 4, 5, and 6.   Then come back and explain why you are wrong.


----------



## texasbo (Aug 30, 2011)

RickAstoria said:
			
		

> I do believe it is potentially possible to design a building using the wooden framing. Many of the common fire-protectionmethods for steel frame can also be used for protect a wood column. What it takes to burn glulam, large built-ups or
> 
> Heavy Timber solid hewn to crisp would melt steel to point of collapse. In either case, necessary fire-protection would
> 
> ...


Rick, you might be on to something here. Consider the following: What if you built this 30 story tall building out of wood, then as you have suggested, you encapsulate the wood with cinder blocks, concrete, steel, refractory brick, space shuttle tiles, etc ? Build it such that it will give you a rated, and noncombustible structural frame, surrounding the wood. Then, you very carefully slide the wood out of the assembly, right before inspection. That might let you have your cake and eat it too, no?


----------



## brudgers (Aug 30, 2011)

texasbo said:
			
		

> Rick, you might be on to something here. Consider the following: What if you built this 30 story tall building out of wood, then as you have suggested, you encapsulate the wood with cinder blocks, concrete, steel, refractory brick, space shuttle tiles, etc ? Build it such that it will give you a rated, and noncombustible structural frame, surrounding the wood. Then, you very carefully slide the wood out of the assembly, right before inspection. That might let you have your cake and eat it too, no?


  Rather than going to the trouble to slide it all out, why not use in place destructive methods ... maybe he could just burn the wood off?


----------



## texasbo (Aug 30, 2011)

Because the inspector would see the remnants of the wood and fail the project for not complying with the building code.


----------



## KZQuixote (Aug 30, 2011)

Coug Dad said:
			
		

> The Tacoma Dome is the world's largest wood dome.  Mark, are you Vancouver BC or WA?


 In the 1980's I was one of the framing carpenters on the 305' diameter wood dome at the University of Portland. I believe it's called the Chiles Center.

Bill


----------



## RickAstoria (Aug 30, 2011)

texasbo said:
			
		

> Rick, you might be on to something here. Consider the following: What if you built this 30 story tall building out of wood, then as you have suggested, you encapsulate the wood with cinder blocks, concrete, steel, refractory brick, space shuttle tiles, etc ? Build it such that it will give you a rated, and noncombustible structural frame, surrounding the wood. Then, you very carefully slide the wood out of the assembly, right before inspection. That might let you have your cake and eat it too, no?


You do an inspection prior to any encapsulation, an inspection at partial encapsulation and after complete inspection as every floor is built before the next floor is built. It isn't rocket science.


----------



## mtlogcabin (Aug 30, 2011)

It could be done with CLT but it would not be classified as a Type I A construction. It would have to be done under the ICC Performance Code for Buildings and Facilities. It would not be possible under the current IBC

[h=2]Cross Laminated Timber (CLT) Benefits[/h][h=3]Strength[/h]


Allows wood to be used in never before seen buildings like 30 storey high rises

Cross lamination creates perfectly uniform strength properties like steel and concrete

Creates new possibilities in cantilevers and load bearing

Less

Due to its amazing strength properties, CLT can be utilized in applications such as high-rises that wood has previously never been adequate for. The high strength properties have more benefits than just being able to build higher and make longer spans, they are evident in all the other amazing advantages CLT has. Any weakness in the individual stick of lumber is cancelled out by the cross lamination with other pieces until there is a single timber panel with uniform strength properties closer to reinforced concrete than wood. Lastly, cantilevers and loads can be designed in any direction rather than just one, offering exciting new design possibilities.

[h=3]Fire[/h]


Low surface area doesn’t sustain a flame so fires burn themselves out

Airtight construction lowers the fires’ oxygen supply, gas does not travel through the panel

Heat does not conduct from side of the panel to the other

Less

The fire performance of CLT is better than any other wood building system. The low surface area and the airtight environment compared to standard wood construction also helps to inhibit fire growth in a contained space by limiting the available fuel. Even a normal installed panel does not allow fire to burn through which encapsulates the flame in a single area, suffocating it. Another great attribute is the solid thermal mass. This allows one side of the panel to be close to 1000 degrees Celsius while the other side is room temperature.

[h=3]Seismic[/h]


Combination of strength, ductility and light weight form the ideal earthquake-proof system

Shake table tests up to 7 storeys prove that CLT buildings have excellent performance

No loss of life or structural damage even against the strongest earthquakes

Less

CLT is immensely strong, ductile, and light; the perfect attributes for an earthquake-proof building system. Seismic tests prove that CLT buildings can handle the world’s strongest earthquakes with no loss of life or structural damage. The high strength-to-weight properties decrease the seismic forces acting against the structure, making these buildings extremely safe while simultaneously allowing for smaller foundations. A 7 storey CLT building was shaken by the world’s largest shake table in Japan by 10 earthquakes and survived perfectly intact. CLT floor spans in a theoretical 24 storey high-rise have shown to reduce seismic load by 50% compared to reinforced concrete.

[h=3]Acoustic and Vibration[/h]


Solid wood panels give excellent acoustic insulation

Vibration design can satisfy the strictest building codes

Construction process is nearly soundless, perfect for urban projects

More

When replacing stick-frame walls, solid timber gives a massive upgrade in acoustic performance. CLT construction gives the home an airtight enclosure of solid mass elements, and with the proper design can satisfy the strictest acoustic ratings even in multi-storey residential buildings.

[h=3]Thermal Insulation[/h]


Ideal building system for Passive Homes - that don’t require heating systems

Can trap 90% of the heated air that escapes from normal homes

High thermal mass of timber keeps home warm in the winter and cool in the summer

More

CLT is perfectly suited for passivhaus designs that are so efficient at insulating a home they don’t need any heating systems. The airtight environment doesn’t allow heat to leave through cracks, while the average home has cracks that add up to the size of a basketball. The high thermal mass of the timber also helps keep the interior temperature stable throughout the day – warm in the day, cool at night.

[h=3]Durability[/h]


Has the best long-term stability of any wood building system

CLT eliminates swelling , shrinkage, warp, and creep – main barriers to normal wood construction

The stability allows for precision building and new higher wood towers

More

Due to the cross laminated engineering, CLT has much better durability characteristics than solid wood. Long-term movement by the wood itself due to swelling, shrinkage, warp, and creep has been minimized to insignificant levels even for the tallest applications, opening up new frontiers for wood construction. Our product is tested constantly to ensure long-term lamination quality.

[h=3]Installation Efficiency[/h]


Manufacturing process minimizes on-site labour with off-site efficiency automation

Panel connections are based on simplified self-tapping screws

Can build a 9 storey building in 9 weeks instead of 27, even with a 4 person crew

More

CLT adds tremendous value to underutilized lumber components by assembling them into precisely-machined building components. The assembly line method of manufacture maximizes efficiency off-site and minimizes the steps necessary to build a structure. We minimize the amount of transportation and manipulation necessary to extract maximum efficiency from the construction process. We simplify the assembly by lowering each panel and screwing it in place with just a few labourers in just 20 minutes. Erecting the shell of an entire house can take as little as 8 hours! Not only is it much safer to do, but it eliminates the waste from fine-tuning, squaring, cutting, and garbage disposal. All this amounts to the major benefits of completing the project in a fraction of the time it would normally take, making it more profitable, easier to estimate, and less risky for the workers, developers, owners, and investors.


----------



## KZQuixote (Aug 30, 2011)

RickAstoria said:
			
		

> You do an inspection prior to any encapsulation, an inspection at partial encapsulation and after complete inspection as every floor is built before the next floor is built. It isn't rocket science.





			
				texasbo said:
			
		

> Rick, you might be on to something here. Consider the following: What if you built this 30 story tall building out of wood, then as you have suggested, you encapsulate the wood with cinder blocks, concrete, steel, refractory brick, space shuttle tiles, etc ? Build it such that it will give you a rated, and noncombustible structural frame, surrounding the wood. Then, you very carefully slide the wood out of the assembly, right before inspection. That might let you have your cake and eat it too, no?


Hey! if you recycled the wood from floor to floor you'd probably earn some additional LEEDs credits.


----------



## brudgers (Aug 30, 2011)

RickAstoria said:
			
		

> It isn't rocket science.


  Heck, it isn't even building science.


----------



## texasbo (Aug 30, 2011)

Exactly. Slide the wood out from the first floor noncombustible/fire rated structure cocoon, and move it up to the next floor. Kind of like slip forming. And kind of not.


----------



## Paul Sweet (Aug 30, 2011)

I agree with mtlogcabin.  Performance code, not IBC.


----------



## steveray (Aug 30, 2011)

I think we all know it is not allowable under current codes,  up for debate might be wether it could be allowable some day and what precautions would need to be taken with engineered wood products that now could physically be used to support a high rise wood framed structure...


----------



## RickAstoria (Aug 30, 2011)

steveray said:
			
		

> I think we all know it is not allowable under current codes,  up for debate might be wether it could be allowable some day and what precautions would need to be taken with engineered wood products that now could physically be used to support a high rise wood framed structure...


Read 703.3 and 703.4. Take not of 703.3 - Item #5.Then look at 104.11. Now, with that in mind, unprotected steel has no fire-resistance rating of any appreciable level under prescriptive methods. If you look at the Prescriptive table of Section 720 regarding Steel. The rating is entirely on the protection. The Steel is treated as having zip for fire protection. So a similar rating can be achieved very easily using the same methods.The attached pic is a concept for a fire-protected wood column. Do note that I did not specify the particular protective shell. They can be CMUs, bricks, multiple layers of Type X Gypsum wall board. The mechanism for adhering them to the wood structure should be similar to any mechanism normally required to adhere the type of protection chosen to the wood like brick veneer over wood studs or columns or whatever else provided the isolation buffer is maintained. 2" is based on the code requirements for wood separation from Chimneys. So the idea would be maintained. The adhering mechanism should be of material commonly allowed in the 2" space between wood studs and chimneys.
	

		
			
		

		
	

View attachment 473


View attachment 473


/monthly_2011_08/572953c13359d_Fire-protectedwoodcolumnsectioncut.jpg.1f851f9511dfac59c14de3b16960cf0a.jpg


----------



## RickAstoria (Aug 30, 2011)

Steveray,

There is ways to do this but we would certainly want to test the assembly. I do believe it is well doable and using an assembly like that already used to protect steel with 3 to 4 hour fire-resistance rating just in the protective "shell" before the steel becomes exposed to excessive heat. Similar systems would protect wood the same way as it does steel. We can amend the code text in the future to allow fire-resistance rated protective shell over wood structural components.

Prescriptive assemblies rates only the shell or coating on steel structure. The core steel member is not part of the fire-resistance rating - only the protective shell or coating.

In my opinion, Type I & II construction requiring non-combustible material (and assemblies) is about fire-resistance rating. In the past, it was not that wood could not be used. It was that you needed things like CMU / Brick or 4-6" of poured concrete shell just to protect the wood with 3-hours rating that it was not systematically practical in economic terms. At a point, you would be better of just using reinforced concrete. Now it is possible to use Type-X drywall in multiple layers to get 3-hr rating and drywall alone would not make for a load-bearing structural material but wood, steel, concrete would make for a load-bearing structural material. In past, we have not engineered wood or hewn wood products that would bear the load that could be encountered in high-rise construction.

In past 50-60 years, we do have members that are stout and strong enough in terms of glulam. However, we need column connections to achieve the goal and certainly other engineering factors to be considered for lateral and moment resistance for both seismic and wind. Sway control would be necessary in the world of high-rise construction with many neighboring buildings.

I think we still need to achieve the spirit of Type I & II by protective covering of the wood. If it means, we need to add 1 additional hour to the required rating in Table 601 for a particular building element to light non-fire resistant coated wood stud members (vs. Fire-resistant coated Heavy Timber / GluLam wood )

Example: 4-hours rated protective shell for non-fire resistant rated wood stud walls. 3-hrs. - if the studs already has a fire-resistant coating. 4-hours rated shell for a non-fire-rated glu-lam. 3-hours shell if the Glu-Lam column has a fire-resistant coating.

A number of strategies can be achieved.


----------



## mtlogcabin (Aug 30, 2011)

How do you get around

TABLE 503 requires all buildings over 11 stories to be Type I A

602.2 Types I and II.

Types I and II construction are those types of construction in which the building elements listed in Table 601 are of *noncombustible materials*,

It just can't be done under todays IBC no matter how much protection you put around combustible materials they are still combustible under the code

The protecion around steel is to limit the steel from reaching 1,200 degrees F where it starts to loose its structural strength and a catastaphic failure can occur. Wood starts to ignite around 572 degrees F so additional testing would have to be performed.


----------



## Coug Dad (Aug 30, 2011)

A 30 story wood high rise would require a code change or approval of an alternate method of design.


----------



## RickAstoria (Aug 30, 2011)

mtlogcabin said:
			
		

> How do you get around TABLE 503 requires all buildings over 11 stories to be Type I A
> 
> 602.2 Types I and II.
> 
> ...


What defines the material as "noncombustible" in code. If the material is injected and coated with 6" of gypsum. The trick in the scenario is that the material of building element is outright noncombustible.

Steel will actually combust if gets hot enough and that is what it would take to get through 8-16 inches of solid Concrete (CMU). Flat out, it is IMPOSSIBLE for normal materials used in a building to get that hot and last that long to cause the wood to combust. If it got that hot, the steel is a pool of hot liquid metal.

Let's look at Non-combustible membrane for a second. Obviously the term is somewhat used to refer to a composite assembly of components. Obviously the membrane is of some material that obviously a composite of a core material that is combustible but due to the manufacturing process, it is coated with elements that makes it non-combustible to Section 703.4 or NFPA 701 flame propagation performance criteria. If the assembly of the building element halts propagation of flame spread right where it is at.

If we need to change the code, that is only a text amendment because NONE of the states have to adopt the building codes exactly according to ICC standards.

I already have considered how the text can be amended. Since a rated construction in Type I can assume that a building can instantly collapse in 3 hours + 1 nanosecond. Any point after the 3-hour mark (where 3-hours is required), the building is potentially at the point of collapsing at an undeterminable amount of time. Steel can collapse in matter of minutes or more depending on the alloy mixture. The prescriptive part in Section 720 (regarding steel) only assumes steel with the same fire-resistance rating as wood. Basically, none. The fire-resistance is in the protective component. Concrete and ceramic clay and brick and some similar materials are the only ones basically non-combustible.

Technically, steel does combust. Get some very fine steel wool and light it with a candle. Wood does that and by-product is carbon (ash). While steel does it differently. Steel has a melting temperature and an ignition temperature. The latter is a little higher than the melting temperature. Wood doesn't melt but has an ignition temperature. Large timbers will ignite to a certain point and then char. However, another factor to bear in mind is that with draftstops and fire blocks, there would lack the air necessary to sustain a fire. Therefore the assembly would be non-combustible.

I think it is all doable. We would want to have some testing and stuff and amend the code appropriately before wood is used in Type I & II construction.


----------



## texasbo (Aug 30, 2011)

RickAstoria said:
			
		

> Some pretty deep thoughts, then: "I think it is all doable. We would want to have some testing and stuff and amend the code appropriately before wood is used in Type I & II construction."


I just want to say that I think it's very sporting of you to require some testing and stuff before we allow wood structural elements in Type I and Type II high-rise construction.


----------



## brudgers (Aug 30, 2011)

RickAstoria said:
			
		

> What defines the material as "noncombustible" in code.


  That would be 703.4, Rick. When you get a code book, you will discover that it has an index.   Then you may discover that two hours typing will save you 45 seconds of code research.


----------



## mtlogcabin (Aug 30, 2011)

> What defines the material as "noncombustible" in code.


703.4 Noncombustibility tests.

The tests indicated in Sections 703.4.1 and 703.4.2 shall serve as criteria for acceptance of building materials as set forth in Sections 602.2, 602.3 and 602.4 in Type I, II, III and IV construction. The term "noncombustible" does not apply to the flame spread characteristics of interior finish or trim materials. A material shall not be classified as a noncombustible building construction material if it is subject to an increase in combustibility or flame spread beyond the limitations herein established through the effects of age, moisture or other atmospheric conditions.

703.4.1 Elementary materials.

Materials required to be noncombustible shall be tested in accordance with ASTM E 136.


----------



## RickAstoria (Aug 30, 2011)

mtlogcabin said:
			
		

> 703.4 Noncombustibility tests.The tests indicated in Sections 703.4.1 and 703.4.2 shall serve as criteria for acceptance of building materials as set forth in Sections 602.2, 602.3 and 602.4 in Type I, II, III and IV construction. The term "noncombustible" does not apply to the flame spread characteristics of interior finish or trim materials. A material shall not be classified as a noncombustible building construction material if it is subject to an increase in combustibility or flame spread beyond the limitations herein established through the effects of age, moisture or other atmospheric conditions.
> 
> 703.4.1 Elementary materials.
> 
> Materials required to be noncombustible shall be tested in accordance with ASTM E 136.


Here is a simple amendment:

603.1 "Allowable Materials." Combustible materials shall be permitted in buildings of Type I or Type II construction in..... in accordance with Sections 603.1.1 through 603.1.3

1. Fire retardant-treated wood shall be permitted in:

1.1 ...

1.2 ...

1.3 ... Exception: ...

1.4 Any other building element, provided all exposed surfaces are protected by passive fire-resistant assemblies that meets the minimum fire-rating required for that building element as required for the Construction Type classification as denoted in Table 601 and elsewhere in this code as required or permitted. All such assemblies shall be tested or approved to meet the required fire-rating in accordance with Section 703.

This would basically address the allowance. This is simply a "draft" language. I think the idea is pretty straight-forward.

I would recommend testing assemblies prior to actual amendment of code.


----------



## RickAstoria (Aug 30, 2011)

texasbo said:
			
		

> I just want to say that I think it's very sporting of you to require some testing and stuff before we allow wood structural elements in Type I and Type II high-rise construction.


That for one could also be something that if tested to provide the required level of protection and safety that it can be outlined prescriptively and if lucky, calculated method can be determined. Sizing the wood structural member and such would be something requiring engineering. I don't necessarily want to rule out wood for tall high-rises but we surely need to take prudent steps. Wood isn't a bad material for something like a 30 story high-rise. We need to consider proper connection ties just as you would with steel I-sections. We also need appropriate connectors and proper bracing. I would doubt the structure would be entirely out of wood. Even a wood frame house is hardly ever entirely made of wood in most cases.

I would expect stair wells (and the stairs themselves & landings) and possibly the elevator shafts to be of concrete / steel. It would allow for another material to be used in such. I wouldn't want someone to just erect a wood high-rise of 30 floors without there being some code guideline to ensure utmost safety.


----------



## texasbo (Aug 31, 2011)

RickAstoria said:
			
		

> I would expect stair wells (and the stairs themselves & landings) and possibly the elevator shafts to be of concrete / steel. It would allow for another material to be used in such. I wouldn't want someone to just erect a wood high-rise of 30 floors without there being some code guideline to ensure utmost safety.


If the structural system of the 30 story highrise is wood, why would you not expect to see stairwell/stairs of wood?


----------



## RickAstoria (Aug 31, 2011)

texasbo said:
			
		

> If the structural system of the 30 story highrise is wood, why would you not expect to see stairwell/stairs of wood?


That is a good point. The stairwell walls could very well use wood structural with the required fire-resistant rated protective shell.

The stair system itself might be a challenge to coat with 3-hour rated protective assembly and such. Perhaps that be possible too. I would probably

expect (for the time being) to have these stair system to be concrete as it would also help as a sort of mass-dampening. Like a spinal chord.

If one can come up with a 1" thick tread plate and kickplate of 3-hour fire rated it could very well work. From my understanding, stairways must be of 2 to 3-hour rated construction but I haven't noticed one way or the other what fire-resistance rating stairs themselves needs to be in Type I. I would almost treat them withe same rating as the floors for the stairs and landings while the vertical enclosure being treated Interior Bearing walls.

As I skim through the other sections, I see 2-hours for the enclosure but the stairs themselves...?

Currently, the economy of using concrete for the stairs themselves is currently the effective method to meet 3-hrs is still part of the challenge. I would be resistant to using Type-X Drywall in multiple layers for the stairs themselves to cover wood.


----------



## TJacobs (Sep 1, 2011)

This is one thread that brudgers has nailed.


----------



## RickAstoria (Sep 1, 2011)

brudgers said:
			
		

> That would be 703.4, Rick. When you get a code book, you will discover that it has an index.   Then you may discover that two hours typing will save you 45 seconds of code research.


Ok. Good. What defined material.

I know it has an index. When words are not defined: Read 201.4.

When we are also talking about building materials and the dictionary definition is broad to apply to context that the definition isn't purely literal.

Material has a wide array of use and scope of meaning both in code but also in practice of use as ORDINARILY accepted and as context applies.

Therefore, we are talking about NON-COMBUSTIBLE (defined within code) building materials.

Are materials strictly limited to natural elementary elements OR does it include a composite assembly as a whole is to function accordingly.

Break down a non-combustible roof membrane into its own sub-parts, are all the sub-parts inflammable. The membrane in itself an assembly of parts.

Lets look at Composite Material. With any research, the topic is deep.

http://en.wikipedia.org/wiki/Composite_material

Now, an assembly of materials can very well become the building element. The assembly of materials are a composite. Therefore a composition. Say a layered composition of brick and wood. It need not be microscopic but can also be macroscopic.

When the definition is to be determine, the unit as a whole much function as a unit. An engineered solution, it may be. I would favor code amendment to minimize stretching the definition to the proverbial limit and simply make it clear and approved in approved assembly where it is protected by a fire-resistant protective shell.


----------



## brudgers (Sep 1, 2011)

RickAstoria said:
			
		

> Ok. Good. What defined material.   I know it has an index. When words are not defined: Read 201.4.   When we are also talking about building materials and the dictionary definition is broad to apply to context that the definition isn't purely literal.  Material has a wide array of use and scope of meaning both in code but also in practice of use as ORDINARILY accepted and as context applies.   Therefore, we are talking about NON-COMBUSTIBLE (defined within code) building materials.  Are materials strictly limited to natural elementary elements OR does it include a composite assembly as a whole is to function accordingly.  Break down a non-combustible roof membrane into its own sub-parts, are all the sub-parts inflammable. The membrane in itself an assembly of parts.  Lets look at Composite Material. With any research, the topic is deep. http://en.wikipedia.org/wiki/Composite_material  Now, an assembly of materials can very well become the building element. The assembly of materials are a composite. Therefore a composition. Say a layered composition of brick and wood. It need not be microscopic but can also be macroscopic.  When the definition is to be determine, the unit as a whole much function as a unit. An engineered solution, it may be. I would favor code amendment to minimize stretching the definition to the proverbial limit and simply make it clear and approved in approved assembly where it is protected by a fire-resistant protective shell.


  Ricopedia is not a reference for the IBC.


----------



## mtlogcabin (Sep 1, 2011)

Ricopedia    LMAO


----------



## RickAstoria (Sep 1, 2011)

brudgers said:
			
		

> Ricopedia is not a reference for the IBC.


Then open your eyes and look around. Most materials in this world is a composite of materials. Very few things are purely their natural elementary material as found in nature.

This can be proven with facts that can be should with over 1 BILLION sheets of documentations including the patent documents as well.

I don't think a B.O. is going to refute that fact. Encyclopedias or Wikipedia is just convenient facts that is more in-depth than a dictionary definition which can be broad but not as in-depth as every documentation of something.

Lets take the question, WHY does Type I & II want non-combustible materials/assemblies used. What level of fire-resistance are they wanting for the material/assemblies before they expect potential failure. This would need a review of commentaries of the I-code and UBC when the requirements were initially enacted. Then review ICC interpretations.

Is it that they don't want building elements that is readibly combustible. Most fire-resistant coated lumber is only 1-hour rated coating. However, they want 3-hours so the issue then is what is wrong with using wood that is protected by a protective shell cladding that is at least 3-hours rated.

It isn't like it'll burn and collapse any faster than a steel frame building with same or similar cladding. Large glu-lam columns that are oversized for the load conditions will char over like heavy timber and then the charing will protect the wood from further combustion as long as the ash char coating stays on the wood - of course. That can be a helpful trait. Another factor to consider is, if the assembly is enclosed, the air would be limited. Therefore, fire would not be sustainable unless there is a continuous supply of oxygen. That would be something a proper assembly would not have unless a hole burns through the protective cladding to supply new air. However, you still have draft stops and fire blocks and that kind of stifles the fire propagation. There has to be a whole in the cladding for new supply of oxygen unless you have a magnesium fire. Which you would know your screwed because that is like Thermite which steel, concrete, and wood is not going to protect against. It will be consumed.


----------



## TJacobs (Sep 1, 2011)

I hope I don't live long enough to see this perversion of construction types.  Type III has already been perverted so as to be meaningless.


----------



## brudgers (Sep 2, 2011)

RickAstoria said:
			
		

> This can be proven with facts that can be should with over 1 BILLION sheets of documentations including the patent documents as well.


  And that's as far as I got.... http://www.youtube.com/watch?v=HY-03vYYAjA


----------



## tmurray (Sep 2, 2011)

I think this conversation might have gotten slightly out of hand. This structure being above three storeys would fall under part 3 of the NBCC. There isn't a whole lot of more information, but as for the fire separations it wouldn't be any problem to get the necessary rating.


----------



## texasbo (Sep 2, 2011)

tmurray said:
			
		

> I think this conversation might have gotten slightly out of hand. This structure being above three storeys would fall under part 3 of the NBCC. There isn't a whole lot of more information, but as for the fire separations it wouldn't be any problem to get the necessary rating.


Well, I'm glad to see we got over the major hurdle of fire separations.

All we have to do now is solve the minor issue of that 30 storey thingy.

However, with each post that Rick Astoria makes, I feel us getting closer.

Welcome to the board, tmurray!


----------



## TJacobs (Sep 2, 2011)

Maybe...just maybe...egg straps?


----------



## steveray (Sep 2, 2011)

Baling wire and duct tape.....but seriously....I like the fact that people think outside the box and look for new ways to do things....do I think it will become a reality any time soon, no, but why shouldn't you be able to protect a wood structure to the point it will last at least as long as a steel one......if the intent is known and met, great...might not be cost effective for the protection, but that is not my problem...


----------



## tmurray (Sep 2, 2011)

texasbo said:
			
		

> Well, I'm glad to see we got over the major hurdle of fire separations. All we have to do now is solve the minor issue of that 30 storey thingy.
> 
> However, with each post that Rick Astoria makes, I feel us getting closer.
> 
> Welcome to the board, tmurray!


I'm assuming you're referring to the structural design.

4.3.1.1.Design Basis for Wood

1)Buildings and their structural members made of wood shall conform to CAN/CSA-O86, “Engineering Design in Wood.”

Assuming a office occupancy our specified loading would be 2.4 kPa, so depending on the actual building layout is do-able.

At this point there isn't really a question of whether or not it is possible, just if the architect can be creative enough to give the structural engineer a place to hide columns.


----------



## RickAstoria (Sep 2, 2011)

tmurray said:
			
		

> I think this conversation might have gotten slightly out of hand. This structure being above three storeys would fall under part 3 of the NBCC. There isn't a whole lot of more information, but as for the fire separations it wouldn't be any problem to get the necessary rating.


Well... I'm not looking at the National Building Code of Canada. Just looking at how to deal with such matter in the United States. What needs to be done and so on.


----------



## RickAstoria (Sep 3, 2011)

Here is the easiest method of getting a wood frame Type I/II structure in the U.S.

104.11 which you determine by Section 703.3 & 703.4 and by general rule to meet the non-combustibility

standard of the code to meet Table 601 and Section 602.2

This quote is from the OSSC 2007. (I know, they have an update and just have to track down the current edition.)

104.11 Alternative materials, design and methods of construction

and equipment.The provisions of this code are not intended to prevent

the installation of any material or to prohibit any design or method

of construction not specifically prescribed by this code, provided

that any such alternative has been approved. An alternative material,

design or method of construction shall be approved where the building

official finds that the proposed design is satisfactory and complies

with the intent of the provisions of this code, and that the material,

method or work offered is, for the purpose intended, at least the

equivalent of that prescribed in this code in quality, strength,

effectiveness, fire resistance, durability and safety.

104.11.1 Research reports. Supporting data, where necessary

to assist in the approval of materials or assemblies not

specifically provided for in this code, shall consist of valid

research reports from approved sources.

104.11.2 Tests. Whenever there is insufficient evidence of

compliance with the provisions of this code, or evidence

that a material or method does not conform to the requirements

of this code, or in order to substantiate claims for

alternative materials or methods, the building official shall

have the authority to require tests as evidence of compliance

to be made at no expense to the jurisdiction. Test methods

shall be as specified in this code or by other recognized test

standards. In the absence of recognized and accepted test

methods, the building official shall approve the testing procedures.

Tests shall be performed by an approved agency.

Reports of such tests shall be retained by the building official

for the period required for retention of public records.

104.12 Request for ruling. ORS 455.060 provides for state rulings

on acceptable materials, designs and methods of construction.

When a ruling has been issued, ORS 455.060(4) applies.

ORS 455.060 is not a part of this code but is reproduced here for the

reader's convenience:

455.060 Rulings on acceptability of material, design or method

of construction; effect of approval.

(1) Any person who desires to use or furnish any material, design

or method of construction or installation in the state, or any building

official, may request the Director of the Department of Consumer

and Business Services to issue a ruling with respect to the

acceptability of any material, design or method of construction

about which there is a question under any provision of the state

building code. Requests shall be in writing and, if made by anyone

other than a building official, shall be made and the ruling issued

prior to the use or attempted use of such questioned material, design

or method.

(2) In making rulings, the director shall obtain the approval of the

appropriate advisory board as to technical and scientific facts and

shall consider the standards and interpretations published by the

body that promulgated any nationally recognized model code

adopted as a specialty code of this state.

(3) A copy of the ruling issued by the director shall be certified to

the person making the request. Additional copies shall be transmitted

to all building officials in the state. The director shall keep a permanent

record ofall such rulings, and'shall furnish copies thereof to

any interested person upon payment of such fees as the director

may prescribe.

(4) A building official or inspector shall approve the use of any material,

design or method of construction approved by the director

pursuant to this section if the requirements of all otherlocal ordinances

are satisfied.


----------



## ICE (Sep 3, 2011)

2,319 views has got to be a record.


----------



## RickAstoria (Sep 3, 2011)

Really with only 5 pages of ramblings on the subject.


----------



## texasbo (Sep 6, 2011)

I see this as perhaps the strongest argument that combustible structural elements are an acceptable alternate material to noncombustible structural elements.

However, I stand fast on my idea of slipping the wood out of the assembly when nobody is looking.



			
				RickAstoria said:
			
		

> Here is the easiest method of getting a wood frame Type I/II structure in the U.S.104.11 which you determine by Section 703.3 & 703.4 and by general rule to meet the non-combustibility
> 
> standard of the code to meet Table 601 and Section 602.2
> 
> ...


----------



## permitguy (Sep 7, 2011)

> Maybe...just maybe...egg straps?


Well done, sir!


----------



## Phil (Sep 7, 2011)

texasbo said:
			
		

> . . . However, I stand fast on my idea of slipping the wood out of the assembly when nobody is looking.


Once you slide the wood members out, the structural challenges could be simplified if you slid in a reinforcing cages with concrete or some steel section. Designing an economical  30 story wood framed building has other challenges besides the fire protection dilemmas.


----------



## texasbo (Sep 7, 2011)

Phil said:
			
		

> Once you slide the wood members out, the structural challenges could be simplified if you slid in a reinforcing cages with concrete or some steel section.


Well there you go; I think we just found the last piece of this puzzle. And as other members have hinted, those elements could very likely be....Tor-Eggs....

See what we can do, when we all put our minds together?


----------



## RickAstoria (Sep 9, 2011)

texasbo said:
			
		

> I see this as perhaps the strongest argument that combustible structural elements are an acceptable alternate material to noncombustible structural elements. However, I stand fast on my idea of slipping the wood out of the assembly when nobody is looking.


I wouldn't worry about the sliding the wood out. Since we can have 3-hr rated assemblies that may not be structural bearing but provide the level of fire-protection necessary to protect the combustible structure that gives us the dual benefit of lightness of the wood (which reduces the weight of the building) but also the long duration and durability wood has with seismic. Steel like many metals have a fatigue factor that can be an issue if bend back and forth (which technically happens in loading condition). Wood does not have quite the same issue.

Another factor, wood is a renewable resource. I do believe we can have a structurally sound wooden "skyscraper" (30-100 stories high) that also provides a great deal of fire protection. It is a feat that needs to be done with DILIGENT care. In the past, we had issues with manufacturing engineered wooden elements large enough to support the load. Fire "proofing" (well it is resistance not true fire proof as nothing exists that is) is the easy part. We already built the "fire-proof" wooden frame houses that had brick or clay tile cladding or other such.

Other considerations needs to be looked at and addressed before we just start making these buildings.

I am not against the use of wood as a structural bearing element of skyscrapers. We have engineered wood columns as strong a steel H-sections of similar size. So it may work if we addressed all the same issues for Life/Safety and Structural.


----------



## Coug Dad (Mar 16, 2012)

The idea marches on

http://www.cnn.com/2012/03/15/tech/eco-wood-skyscrapers/index.html.


----------



## Big Mac (Mar 16, 2012)

I agree - let's build a CONCRETE WOOD AND STEEL structure.  Hold the wood.


----------



## gbhammer (Mar 16, 2012)

Its a Green thing. :banghd green :banghd


----------



## Architect1281 (Mar 16, 2012)

Uh Huh its a marketing thing


----------



## Architect1281 (Mar 16, 2012)

Maybe it could be NET ZERO too


----------



## gbhammer (Mar 16, 2012)

Maybe the white house can push for the tax payer to give a few billion to Mr. Green to develop the idea for us here in America, and when it fails we :banghd with some congressional investigations. I'm sure the tax payer will net zero


----------



## ewenme (Mar 16, 2012)

A note to Brudgers:  Why do you delight in telling people they are WRONG, when you could be just as wrong. Why tell them you 'patently disagree with their position.' Wouldn't that promote civility and a much livlier discussion.  IMHO, you are not perfect and not right 100% of the time. Neither is anyone else. That's why this forum is so valuable. :butt


----------



## Architect1281 (Mar 18, 2012)

because brugers like myself revel in being right once in a while in an area that perhaps our partners cannot -----

Yes dear I'll be there in a min. ... bye guys


----------

