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30 story wood high rise building

At least the scaffolding will be stronger than the building.

I can see already the steel workers picketing the construction site.
 
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.
 
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.
Click to expand...
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.
 
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. .
Click to expand...
Late and wrong.
 
brudgers said:
Late and wrong.
Click to expand...
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.
 
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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.
 
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.
 
Last edited by a moderator:
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.
Click to expand...
Rick, no matter how many seemingly relevant terms you dump into your post it is still wrong.
 
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 said:
Rick, no matter how many seemingly relevant terms you dump into your post it is still wrong.
Click to expand...
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.
 
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.
Click to expand...
Rick, Open your code book and review chapters 3, 4, 5, and 6. Then come back and explain why you are wrong.
 
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

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.
Click to expand...
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?
 
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?
Click to expand...
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?
 
Because the inspector would see the remnants of the wood and fail the project for not complying with the building code.
 
Coug Dad said:
The Tacoma Dome is the world's largest wood dome. Mark, are you Vancouver BC or WA?
Click to expand...
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
 
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?
Click to expand...
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.
 
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