radial rib support.htm
RADIAL AND RIB
TEMPORARY SUPPORT SYSTEMS
What supports are used to hold up
the component panels until the dome shell kit is assembled?
A: Our Dome Building Kits are erected using a system to temporarily hold the panels in place until the all the seam concrete and options' concrete has cured. The systems (Radial or Rib) are dismantled upon completion of the dome and the 2x4s are recycled as part of the interior framing.
The Radial System is most suitable for a small construction crew and is usually used on our smaller domes, 22', 27’, 30’ and 34’ because the panels weight less and the center height is less. As each panel is placed, a measurement is taken from the panel point to the center of the dome to assure correct positioning. The panel is then held by 2x4s braced against the floor while the seams are concreted.
The advantages to the Radial System over using the Rib System Option are:
Panels can be raised using a rolling scaffold and a winch rather than having to rent a crane.
The Radial System saves the time of cutting and drilling holes in the 2x4 ribs.
The Radial System saves the time of erecting and dismantling the Rib System.
It also uses fewer materials.
Click on the photo to enlarge it.
This is a 34' dome being built on a Some triangle panels are
Basement utilizing the being supported with 2x4's.
radial support method. Some of
the entryway panels are
being supported with 2x4's.
The riser wall and the first row Some second row triangles
of hexagons and pentagon panels are being installed next to some
have been installed using the radial entryway panels using the
support method. radial support method.
The Rib System is most suitable for a large crew and a fast paced construction. The Rib System is preferable on the larger domes 40, 45, 48 and 60'. The Rib System consists of using your own 2x4s and 46 steel hubs on loan from America Ingenuity to erect a free standing framework matching the geometry of the dome. The geometry of the dome consists of five rows of panels....the first row is the riser wall, then four rows of triangles with the fourth row consisting of the top five panels.
The Rib System is bolted together from 2x4’s and color-keyed hubs. The Rib System is usually assembled on the ground working from the top to the bottom and hoisted up as you add each row below the last.
This means the first row that is assembled is the top row. Once assembled this row is hoisted up and the fourth row of 2x4's and hubs are added to this row. This continues until the third and second rows of 2x4's and hubs are assembled and hoisted up. The last row that is assembled is the 2x4's and hubs for the riser panels. See the Rib System pictures below.
A scaffold tower (which we illustrate in our Assembly Manual) or a long reach lifting device can be used to lift the rib system.
Tools and Materials needed:
· Set of steel scaffolding to reach at least the dome height plus three feet
· Five cable hoists (come-a-longs)
· 9/16” Wrenches and ratchet
· 46 hubs, 255 bolts, nuts, and washers
· 15 diagonal braces-2x4x8’ studs
· 100’ plus of rope, 500 lb. test
· Precut and color-coded wood ribs
· Two pounds 12d or 16d common nails
With a Rib System in place, a crane or hoisting mechanism can be used to set as many as two rows of panels in one day. Since the Rib System reflects the dome geometry, a panel cannot be inadvertently positioned incorrectly.
Once all the concrete cures in the seams and on the entryways, dormers, link, cupola, etc. the rib system is disassembled, the hubs are returned to American Ingenuity and the 2x4s are recycled as interior framing.
Click on the photo to enlarge it.
The center scaffold with cable Three rows of the rib system
hoists is in the center of the slab. have been assembled and
Two rows of the rib system have lifted up.
been assembled and lifted up by
First row of the rib system 27' Dome being assembled 34' Dome being assembled
being assembled. with rib system on top of full basement
The rib system has been The riser wall and one
assembled using the steel hubs row of triangles has been
and 2x4's. installed onto the rib system
What is the rental charge for the steel
hubs? Once I am finished with the steel hubs, how do I get a refund?
A: The rental charge is a $500 deposit for the steel hubs, bolts, nuts, washers, etc. to be kept for 4 months. After that the rental fee is $10 per month. The deposit is placed when you purchase the Building Kit.
If the hubs/bolts are returned to us intact within the four month period, the complete $500 deposit is returned. Thereafter, we subtract $10 for each additional month the hubs are kept and return the deposit difference to the client.
The dome owner pays the UPS shipping costs to return the steel hubs, bolts, nuts, etc. to us.
Can I purchase the 2x4's for the rib
system precut and the holes drilled in them?
A: Yes. Due to fluctuating prices on the 2x4's please call us for pricing.
The pricing will be for the 2x4’s precut to the proper length with a predrilled hole. Add $60 for a second drilled hole for use with a second dome. The 2x4's that are used are lightweight wood, not pressure treated. We ship the precut, predrilled 2x4's on the truck with your building kit. Remember these "supports" are temporary there is no wood in the shell to interrupt the insulation or to rot or for termites to eat.
DOME SIZE Please call us for STRUT PRICING
I would like to have the rib system
assembled by the working consultant. Will the working consultant cut the
2x4's to length, drill the holes and assemble the wood skeleton?
A: Yes but he will need laborers to assist him. Click on Kit Assembly Consultant for more info.
Q: How many 2x4's are needed for the rib system?
A: The 22’ & 27’ need 75 - 2x4’s. The 30', 34', 40', 45', 48' require 135 - 2x4's. The 60' needs approximately 200 - 2x4's.
Q: What length 2x4's are needed for the rib system?
A: The 27', 30', 34' and 40' domes use eight foot long 2x4's. The 45' and 48' need ten foot long 2x4's.
Q: Can I remove the temporary supports too soon?
A: Yes you can. The dome shell is not self supporting until all the panel seams are concreted and all the building options have been concreted. This means "Do not remove the rib system until the concrete on the dormers, entryways, link, cupola and seams has cured."
Q: Why can the dome shell be self supporting with no need for interior load bearing walls to support it?
A: Manufactured geodesic dome home kits are constructed using a triangular network to form a spherical shape. The triangle shape is the strongest shape known to man. The geodesic dome construction method using triangles, provides for a free-span, self-supporting structure requiring no internal supports such as roof load bearing partition walls. This allows for maximum flexibility of floor plan design and utilization of interior space.
As an architectural form, the dome is one of the strongest structural forms devised and built by man. Domes that were built centuries ago enclose many of the great cathedrals of Europe. Domes are structurally superior to rectilinear enclosures. The partial sphere is an aerodynamic shape that is very stable in high winds and can withstand heavy snow loads. For these reasons, residential domes greatly exceed the structural requirements of the major building codes in the United States.
The dome, or partial sphere, is a geometric form that encloses the greatest amount of volume with the least amount of surface area. Historically, massive domes constructed of stones, brick or concrete were common in ancient Greece and Rome. In modern times, Buckminster Fuller was the first to formulate geodesic principles for constructing a spherical surface by triangular subdivision.
Q: What methods are used to lift the panels?
A: The methods used for lifting the panels includes; Small cranes, Highlifts (all terrain scissors forklifts often used by roofers), and A steel scaffold rigged with wheels and winch. Other lifting devices successfully employed by our dome owners include: a boom added to a tractor, a block & tackle, & a hoist fastened to the top of the framework with wood ramps up the side of the dome. Click on Hoisting Mechanisms to learn more.
Monthly rentals on transverse lifts also called Boom Lifts, Horizontal Boom Fork Lifts, Roofing Lifts, Shooters are available from National Rental Chains like US Rentals, Hertz Equipment Rentals, United Rentals, etc. The companies can be found in the telephone book.