Hi my name is Joeziah and I recently (about a year ago) in architecture and engineering, I'm unemployed at the moment, not by choice, but I have a good family and never borrowed money...yada yada.
I made a quick model of an idea for a home I've been thinking about, but the main feature of the home is going to be a curved vault ceiling that spans approx 80'.
Its far from final obviously but one thing i've been trying to learn about is building most of the main structure of the home with cast in place concrete, 12" of it too on all the main walls.
What I'm wondering is how in the world I would achieve the ceiling with concrete.
How would I build those forms to get a smooth curvature of the roof?
Like I said I'm not really schooled in engineering at all but I would really like to get into concrete home architecture.
Any pointing to online resources would be great, I'm not familiar with the lingo in concrete engineering so I've been lost in trying to Google help on this.
Ok so I've been searching around and have figured out that the type of roof I want to build is a Catenary vault, thin shell concrete structure.
I learned some calculus on the beams and figured out that I could do a monolithic pour of the roof on some type of form work and it would easily span 80' and not only support it's own weight but be structurally sound to handle much more load (not that it would be a good idea to drive a truck over your roof).
the problem is figuring out a cost effective formwork, my initial plan was to use three steel i beams delivered in 3 pieces in the needed curvature of the span and connect them into place with a rented crane, the problem here is that the crane is expensive, as are the fees for having steel beams bent + the cost of the beams in the first place and delivery. But you would only need to use 2x4 arrays to span the 10-12 foot spans between said beams which would be way overkill to hold up the concrete roof, and one could even leave these in place along with the steel beams for even more safety.
The other idea is to go ahead and pour the main 80'x50' area including the drop etc before the roof is laid out. After that you would build a massive network of scaffolding to support the form work of the roof, and then disassemble the scaffolding when the roof cures and supports its own weight.
I think the scaffolding would be more expensive then using the steel i beams to span and create a form work webbing off of, another would be that the steel would provide a easy curvature to follow when building the actual structure and would allow the roof to go up before starting the form work on the main structure.
I just googled for a forum for help, so if this really isn't a forum focused on development or whatever let me know so I can go elsewhere for help etc.
ya it can actually be poured over a inflated balloon, but not this amount, total roof weight.
we're talking around 200,000lbs of reinforced concrete for the roof or about 100 short tons.
that is with a 4 inch thick shell, which is what would be needed to hold up its own weight plus a bit more.
If I were to use steel i beams every 12 feet they would each bear a total distributed load of about 54,600 lbs, once the concrete dries though in this arched formation it should be able to hold far above and beyond its own weight.
the beams just need to be strong enough to hold up as form work with the 2x4 arrays spaced every 24" to follow the curvature of the beam.
the project seems to be coming along well, its going to cost way too much for me to build for myself though *NOT a DIY project* but I mean I would be the home designer which should shave a decent amount of money off the cost.
I would just like to get some feedback from any bored engineers. ^_^
Nov 3, 11 4:01 am ·
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Advice for a Novice plz!
Hi my name is Joeziah and I recently (about a year ago) in architecture and engineering, I'm unemployed at the moment, not by choice, but I have a good family and never borrowed money...yada yada.
I made a quick model of an idea for a home I've been thinking about, but the main feature of the home is going to be a curved vault ceiling that spans approx 80'.
Its far from final obviously but one thing i've been trying to learn about is building most of the main structure of the home with cast in place concrete, 12" of it too on all the main walls.
What I'm wondering is how in the world I would achieve the ceiling with concrete.
How would I build those forms to get a smooth curvature of the roof?
Like I said I'm not really schooled in engineering at all but I would really like to get into concrete home architecture.
Any pointing to online resources would be great, I'm not familiar with the lingo in concrete engineering so I've been lost in trying to Google help on this.
Thanks in advance!
Ok so I've been searching around and have figured out that the type of roof I want to build is a Catenary vault, thin shell concrete structure.
I learned some calculus on the beams and figured out that I could do a monolithic pour of the roof on some type of form work and it would easily span 80' and not only support it's own weight but be structurally sound to handle much more load (not that it would be a good idea to drive a truck over your roof).
the problem is figuring out a cost effective formwork, my initial plan was to use three steel i beams delivered in 3 pieces in the needed curvature of the span and connect them into place with a rented crane, the problem here is that the crane is expensive, as are the fees for having steel beams bent + the cost of the beams in the first place and delivery. But you would only need to use 2x4 arrays to span the 10-12 foot spans between said beams which would be way overkill to hold up the concrete roof, and one could even leave these in place along with the steel beams for even more safety.
The other idea is to go ahead and pour the main 80'x50' area including the drop etc before the roof is laid out. After that you would build a massive network of scaffolding to support the form work of the roof, and then disassemble the scaffolding when the roof cures and supports its own weight.
I think the scaffolding would be more expensive then using the steel i beams to span and create a form work webbing off of, another would be that the steel would provide a easy curvature to follow when building the actual structure and would allow the roof to go up before starting the form work on the main structure.
I just googled for a forum for help, so if this really isn't a forum focused on development or whatever let me know so I can go elsewhere for help etc.
thx in advance for feedback.
80 ft? that is a gigantic house!
can concrete be poured over an inflated balloon?
ya it can actually be poured over a inflated balloon, but not this amount, total roof weight.
we're talking around 200,000lbs of reinforced concrete for the roof or about 100 short tons.
that is with a 4 inch thick shell, which is what would be needed to hold up its own weight plus a bit more.
If I were to use steel i beams every 12 feet they would each bear a total distributed load of about 54,600 lbs, once the concrete dries though in this arched formation it should be able to hold far above and beyond its own weight.
the beams just need to be strong enough to hold up as form work with the 2x4 arrays spaced every 24" to follow the curvature of the beam.
the project seems to be coming along well, its going to cost way too much for me to build for myself though *NOT a DIY project* but I mean I would be the home designer which should shave a decent amount of money off the cost.
I would just like to get some feedback from any bored engineers. ^_^
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