Replies

1. 
   Frozen | Aug 15, 2005 05:21pm | #1

   I doubt even civil engineers ever calculate this for the buiding as a whole, just point loads and bearing on walls. And those numbers include the estimated maximum loads added by the occupants and their stuff.

   Buckminster Fuller, the inventor of the geodesic dome, used to ask this question rhetorically, because nobody ever bothers to figure this out. Fuller, as a naval engineer, was constantly considering the weight of everything he designed because it would have an effect on ships' freeboard.

1. 
   rez | Aug 15, 2005 05:51pm | #2

   Frozen-

   Did Bucky really invent the geodesic or was he the one who furthered the thought into practicality?

   Reason I inquire is it seems I recall reading somewhere about an engineer in Germany that designed and built a dome before Buckminister did and somewhere there was an association between the two.

    

    

   A person with no sense of humor about themselves is fullashid 

1. 
   Frozen | Aug 15, 2005 06:05pm | #3

   You are right, according to the Fuller FAQ:[From Lloyd Kahn]Fuller did not invent the geodesic dome. It was invented by Walter Bauersfeld of the Zeiss Optical Works in Jena, Germany in 1922, and the first use of it was as a planetarium on the roof of Zeiss that year.I should have said "developed" or "popularized". Just thought it would be the easiest way to describe BF to anyone that didn't know who he was.

1. 
   LeeLamb | Aug 15, 2005 07:18pm | #4

   In the late '50s I watched this dome being built. It still gives me a thrill when I visit it. The building under it is fascinating. Its rainfall handling system relies on controlled waterfalls instead of downspouting. The water falls into stone filled circular cutouts in the pavement. The garden and mineral display is breathtaking.  This is northeast Ohio's best kept secret. 

   http://www.gardendome.com/asm/asm_dome.html

   or

   http://www.asminternational.org/Content/NavigationMenu/AboutASM/MaterialsPark/MaterialsPark.htm

    

    

    

2. 
   rez | Aug 15, 2005 07:21pm | #5

   Ya, regardless, the man was a real pioneer.

   Always liked his floating city concept and the global map sphere.

    

    

   A person with no sense of humor about themselves is fullashid 

3. 
   Pierre1 | Aug 16, 2005 07:11am | #18

   The USA pavilion at Montréal's world EXPO (1967) was designed by BM. Really cool building and exhibits. It was abandoned for many years, then restored and is still standing. Still looks super cool. 

1. 
   rez | Aug 16, 2005 11:11pm | #22

   Recalling the Expo67 USA Pavilion thru a 12 year old's eyes it was my first escalator ride, the  foreigners, the space crafts hanging, if I remember correctly, from the ceiling, huge indoor fish tanks and the big globe building.

   Still can't say the cap collection impressed me tho'. :o)

    

   Edited 8/16/2005 8:01 pm ET by rez

2. 
   Pierre1 | Aug 17, 2005 05:08am | #23

   Yeah, I think there was a Gemini capsule (big enough for two astronauts to squeeze into) hanging there...the escalator ride took us right past it. The blistering from re-entry was evident.

   I was a space exploration fan then - still am in some ways, even though NASA has unfortunately lost much of it's shine. They still do amazing work, esp. the interplanetary missions.

   The Ruskies had their pavilion directly across the mid-river channel, linked by a bridge. They had a spacecraft as well. Did you check it out?

   Those were the good old days when we knew who the bad guys were. The bad guys - commies - kept their population under surveillance. They arrested people on the basis of their neighbours' turning them in for contra-revolutionary thoughts. Citizens had to answer police questions and undergo arbitrary searches of their persons and their residences. Soviet armies solved problems by invading other countries. Citizens even had to produce ID upon demand, so their names could be checked against lists. Imagine that. What would our lives be if we hadn't won the Cold War?  ;)

    

3. 
   rez | Aug 18, 2005 03:43pm | #24

   Don't recall to much else but might have seen the russian craft. Lost in the mind of a 12 year old perhaps.

   Do recall a Japanese fella gesturing mime at me. He couldn't speak English and I looked at him like 'huh' till I realized he was trying to find out what time it was from my watch.

   Makes me wonder what the weight of that expo building came in at?

    

4. 
   Pierre1 | Aug 19, 2005 05:17am | #25

   Don't know about the weight. Do you recall hearing the Mexican brass band? High energy entertainment.

   What about the Italian pavilion? Remember the spooky tunnel entrance, a mock-up of the cellars in which hundreds perished at Pompei a couple thousand years ago? You'd walk along a mock archaeological excavation, with well preserved bodies partially exposed from under the ash layers. They were clothed and wore jewellery. You could see the skeleton bones.

   Edited 8/18/2005 10:22 pm ET by Pierre1

5. 
   rez | Aug 19, 2005 05:40am | #26

   Pierre-

   You gotta be older than me.

   My priorities over the Expo at 12 was more like raiding the campground trash cans in search of beer cans to add to my collection.

    

6. 
   Pierre1 | Aug 19, 2005 08:00am | #27

   Did the beer help you notice Montréal women? ;)

7. 
   rez | Aug 19, 2005 03:10pm | #28

   Back then was more like stealing an occasional sip 'cause I liked the bubbles.

    

   be a bubble dancer

    

8. 
   RickGreg | Aug 19, 2005 04:05pm | #29

   Now we can replace the "what's the cost per square foot" question with "How much per pound?" ; )

9. 
   rez | Aug 19, 2005 04:37pm | #30

   Ya, that was pretty poor. Sorry to all for the hijack of what should have been in the Shed.

    

    

   be I'm headin' for the shed on my own so momma cut a short switch this time please

    

2. 
   Piffin | Aug 16, 2005 03:49am | #12

   didn'tchjaknow? all good engineering comes from germany 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

2. 
   BobKovacs | Aug 15, 2005 07:37pm | #6

   You don't need to calculate the total weight of the building materials, furniture, etc.  The building code gives you required dead loads, live loadsand snow loads per SF.  You then determine how much load is being transfered to the exterior walls and interior posts based on the areas contributing load to each member. 

   For example, if you have a single story house that's 24' deep and the total live and dead loads for the floor system is 75#/SF, in a conventional center bearing wall layout, there would be 6 LF of floor system load being transfered to each LF of exterior bearing wall.  This equates to 450#/LF.  You do the same calcs for the ceilings, roof, etc., and that determines the total load on the exterior wall.  Divide that by the allowable bearing capacity of the soil, and you get the footing width required.  The same analysis is done for interior posts, etc.

   Bob

1. 
   brownbagg | Aug 15, 2005 08:10pm | #7

   my house weighs 1013 lbs per lineral foot, remember to weigh the footer too.

1. 
   Piffin | Aug 16, 2005 03:53am | #13

   that footer is going to be my ankle anchor. I better make that footer 9" wide;) 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   brownbagg | Aug 16, 2005 04:33am | #14

   but minimum width of a footer is 12 inches due to a cmu is 8 inches and a block can only use 2/3 of the footer.

1. 
   Piffin | Aug 16, 2005 05:39am | #15

   I know, I'm speaking theoreticly on the one issue with one example soil only 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

2. 
   brownbagg | Aug 16, 2005 06:25am | #16

   well from the soil point of view, if you have a sand that capable of 2000lb sq foot, we like to go 75% of that so you would have a safety factor. that would be 1500 ibs or just widen the footer to about 18 inches. but then right now I,m just making conversation.

3. 
   Piffin | Aug 16, 2005 06:31am | #17

   I believe I've seen figures as low as 600 - 800#/ft on our clay here. That sound right? 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

3. 
   JohnSprung | Aug 15, 2005 08:54pm | #8

   I've done the detailed arithmetic for actual dead load on two buildings.  One was a 4 story 30 room brick hotel, 1500 tons.  The other a 3100 sq. ft. two story stucco house, 175 tons.  Going by book values will give you something higher than the actual weight.  The book values are intended to be worst case, so if you design for them, you're more than well covered.

    

    

   -- J.S.

    

1. 
   Pierre1 | Aug 16, 2005 07:17am | #19

   Was talking about this with a house mover last week. He showed me a 2½ storey he'd jacked up. Wood frame, 80 y.o., 1000-1100 s.f. Mover guy said it weighed approx. 50 tons. He's been doing this for 40 years so I believed him.

   This is in line with your 175 ton, 3100 s.f. 2 storey stucco home example.

1. 
   BillBrennen | Aug 16, 2005 08:07am | #20

   What I am seeing is an approximate value of 100 pounds mass per square foot for conventional frame houses. Rule of thumb?Bill

4. 
   CloudHidden | Aug 15, 2005 10:21pm | #9

   I calc the weight for buildings I design. I can get pretty close on the concrete and steel, which will tend to overwhelm other stuff. We do use that, along with snow loads, etc to size footers. Be/c of our construction we're much more focused on overall loads than point loads, and usually have smaller footers than traditional houses.

5. 
   constantin | Aug 16, 2005 02:49am | #10

   I suppose that the architects and statics professionals have some pretty good lists that are based on lb/sq ft for different schedules of floors, walls, etc. However, if you really want to find out, the only way to really know is to weight the thing when it's done, full of toys, etc.

   Our home weighed about 56 tons when it was empty, gutted, the back 20% missing, and it was 5 feet in the air.

6. 
   Piffin | Aug 16, 2005 03:47am | #11

   Dead loads are presumed at up to fifteen pounds per sq ft and live loads at thirty to fifty depending on room intended use, plus 25 to 110/ft for live loads on roof, depending on snow zones. A foundation needs to handle not only the dead load of what the buiolding itself weighs, but it bears the live loads also.

   So for sale of simplicity, a rectangular two story structure with a flat roof in a sniow zone requiring roof load capacity of 50#/ft, when said structure is 1000 sq ft;

   first floor - fifteen dead plus fifty live = 65 #/sf x 1000 = 65000
   second floor - fifteen dead plus forty live = 55#/sf x 1000 = 55000
   roof - fifteen dead plus fifty live = 65#/sf x 1000 = 65000
   total 185000 pounds max potential.

   unless the occupant collects books, tools and gold, and sleeps in a waterbed, he/she is likely to never actually approach this maximum, so it is reasonable to design footings for less. What that standard is, i don't know, but presume that info is given in code references.

   but let's suppose that we must design our footing to the max potential. Imagine that ourt soils engineer tells us that the soil we have can be compacted to bear a load of 2000#/sf. That 185K# must be deistributed over enough footing so that the soil can resist the load. If I divide 185K by 2000, I find that I need around 92.5 square feet of sole for my feet.

   Given my 140 lineal feet of foundation, it looks like the footer only needs to be 8" wide to support that structure on that soil.

   if this structure sits on a rectangular 20 x 50 foundation, it bears on aprox 140 lineal feet of footing.

    

    

   Welcome to the
   Taunton University of Knowledge FHB Campus at Breaktime.
    where ...
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1. 
   JohnSprung | Aug 16, 2005 09:19pm | #21

   > unless the occupant collects books, tools and gold, and sleeps in a waterbed, he/she is likely to never actually approach this maximum, ....

   Back in my Venice Beach days, I had a geologist tenant.  Nice guy, but he had a scary amount of rocks in that apartment.  ;-)

    

   -- J.S.

     

    

   -- J.S.