Concrete Pilings Pilings with oval Concrete Platform
for 40' Dome and 34' Screen Dome
faq foundations.htm
FOUNDATIONS FOR AMERICAN INGENUITY'S DOMES
CONCRETE PILINGS AND CONCRETE PLATFORM
Concrete Pilings Pilings with oval Concrete Platform
for 40' Dome and 34' Screen Dome
Concrete Dome with Cupola Built in Mid 80's
(Cupola's look different now...
not so tall and there are overhangs
that extend out from the top panels)
DOMES BUILT ON BASEMENTS
8" thick solid concrete First Floor wood joists
basement walls for set on top basement walls
34' Dome
Dome on Basement Wall Back view of same dome Front view of same dome
this side of the basement with basement entrance
is bermed with dirt Dome has cantilevered deck
and French Drain installed
Interior View of Basement Exterior View of the same
looking down into basement from basement showing 45' Dome
second floor of dome.
34' Dome on Basement
CONCRETE SLAB
Slabs poured for Concrete Dome Same Dome With
Dome and Screen Dome on Slab Screen Dome
Click on the question to read the answer.
Does A.I.'s geodesic domes have to be built on a special foundation?
Do you modify or design custom basement plans?
What materials can be used to build the basement walls?
Can you provide plans for a wood foundation or connections to existing buildings?
Are there any special requirements for the foundation?
Will the foundation for the dome cost more to build than a conventional shaped foundation?
How deep will the footings be?
How is the below ground basement built and how is the dome attached to the basement walls?
Can you provide basement plans using concrete block, poured walls or insulated concrete forms?
How thick are the basement walls?
Will my soil hold the weight of the dome?
If I build my dome on a basement, will I need to install a French drain?
Can I berm or backfill dirt up around the outside of my dome?
Q:
Do A.I.'s geodesic domes have to be
built on a special foundation?
A:
No, the
domes can be built utilizing the same foundation choices as conventional
housing. The foundation types that we design are a) a monolithic concrete slab
b) poured footing with a stem wall and then a poured slab on fill c) poured
footing with a stem wall and then a raised wood floor d) basement and e)
pilings and a platform. The type of foundation you build depends on
which is more advantageous for your area.
We can do a concrete wall to support the dome and a wood first floor.
We can replace a concrete slab with raised wood floor and design the first floor joist. The cost depends on the complexity from $50-$75 for the residence dome. The garage dome would need a concrete slab.
You can prepare and construct the foundation and later erect the dome.
Q:
Do you modify or design custom basement
plans?
A:
Yes, we can
design custom or modified basement plans for a reasonable cost. Fax or email
your sketch to us and we will call you back with questions and a price quote for
us to design your building plans.
Q:
Can you provide basement plans using
concrete block, poured walls or insulated concrete forms?
A:
Yes, we can
provide plans for most types of basement wall systems utilizing concrete or
block including insulated concrete forms or precast basement wall panels.
Q:
What materials can be used to build the
basement walls?
A:
A
company named, Superior Walls, supplies precast insulated concrete wall panels.
Their number is 800-452-9255 or go to their web site
www.superiorwalls.com
Foam Blocks filled with Concrete are referred to as ICF for Insulated Concrete Forms. These blocks are easy to use and provide insulation. Their high cost is offset by labor savings in the assembly. Some of the many manufacturers are listed below. Call and ask them for the nearest supplier to you.
Reward Wall System, 800-468-6344, www.rewardwalls.com
Eco Block, Dallas TX, 800-595-0820, www.eco.block.com
Poly Steel, Albuquerque NM, 800-977-3676, www.polysteel.com
Insul Deck, Florence KY, 800-475-6720, www.insul-deck.org
Arxx, Alexandria Bay NY, 315-482-5253, www.arxx.net
Q:
Can you provide plans for a wood
foundation or connections to existing buildings?
A:
No, we cannot
provide Building Plans for wood foundations, connections to existing buildings
or unusual designs that are beyond our knowledge.
Q:
Are there any special requirements for the
foundation?
A:
The only thing unusual about our foundation
is its shape. Because our dome is lighter than most other buildings, it has
less loading on the foundation. Reinforcing bars connect the riser walls to
the foundation at the vertical seams. Our stock building plans include drawings
for a concrete slab foundation. Plans for raised wood floors or basements are
available.
Q:
Will
the foundation for the dome cost more to build than a conventional shaped
foundation?
A:
Probably.
The multiple sided foundation for our dome is only slightly more difficult than
a conventional house and should not affect the cost more than 10% at most 20%.
If you would mark the corners of the foundation, this will help remove a lot of
the fear from the subcontractor. You will find that they will give you
a better price. The tolerance on the foundation is very forgiving. You can be
off one to two inches in any dimension without any significant consequences.
Q:
How deep will the footings be?
A:
The
footing depth is determined by the building department in each area.
Q:
How many yards of concrete is needed for
the foundation and how many bags of cement will be needed to concrete the seams?
A:
The number of bags of Portland cement needed to finish the shell varies
depending on the number of entryways and dormers and whether you have a cupola
or a link. The following is a bag estimate to concrete the seams.
DOME SIZE FOUNDATION CONCRETE PORTLAND CEMENT #94 FOR SEAMS
22' 9 Yds. 30 - 40 bags
25' 8.59 40- 45 all based on 4”slab
27' 10.00 40 -45 with 12” deep
30' 11.54 50- 55 perimeter footing
34' 14.31 60- 65
40' 19.00 70- 75
45' 23.39 80- 85
48' 26.26 90-100
60' 130-140
Q:
How is the below ground basement built
and how is the dome attached to the basement walls?
A:
The below
ground basement can have the slab poured first with the exterior basement walls
built on top of the slab or the footings can be poured separate with the
exterior basement wall built on top of the footings and then the slab poured
inside the basement wall. Basement walls are usually 8" thick when made of
poured concrete but will likely increase depending on the height of the basement
wall and the height of the backfill.
We have basement plans available that explain how the dome is attached to the basement, etc. for example rebars need to come out of the basement wall to connect into the dome riser walls, etc.
When the dome is built on a basement, the first floor framing of the dome is typically built with wood 2x10’s which are supported by the concrete basement walls. You can use wood, steel or manufactured trusses for the floor joists. The E.P.S. insulation of the riser panels rests on the wood floor. Concrete is placed between the basement wall and extends up to join with the concrete of the panels. At the corners of the basement wall a column of concrete is formed that will extend up to the reinforced seams between the riser panels. Rebars are anchored in the basement concrete wall corners and are positioned to extend up through this concrete column into the riser wall vertical seams. When the concrete is in place the entire load of the dome bears on the concrete and not on the wood framing.
Q:
How thick are the basement walls?
A:
Basement
walls are usually 8" thick when made of poured concrete but will likely increase
depending on the height of the basement wall and the height of the backfill.
Q:
If I build my dome on a basement, will I
need to install a French drain?
A:
Yes. Included in the basement building plans will be a French drain sheet.
The
steps to install the French drain are:
1) Cover any part of the basement wall that will be in touch with soil with a tar emulsion (designed for this purpose). This waterproof coat should extend down to (and if possible, under) the polyethylene vapor barrier.
2) If you wish, you may add additional waterproofing. Apply roofing felt over the tar emulsion, overlapping the edges 6” and sealing the felt with more tar. Place the roofing paper over the outside of the vapor barrier to shed water. Then, give the whole wall one more coat of tar. This extra investment will provide a superior measure of protection against moisture. Please, don’t cut corners.
3) Place a perforated drainpipe (at least 3” in diameter. - 4” diameter. For long lengths), holes down, into the gravel bed. The pipe should be below the floor level and drop 1” for every 8’ of length. This discharges water into an area lower than the dome itself and allows quick drainage away from the building. Lay pipe in the gravel bed and cover gravel with two layers of roofing felt to prevent dirt from penetrating into the gravel.
4) Backfill the entire area.
Q:
Will my soil hold the weight of the
dome?
A:
If you
have any question about your soil’s suitability, you would need to consult with
someone locally possibly your building department or a soil’s engineer. Our
foundation does not require anything more than 2,000 lbs. per sq.ft. soil bearing
capacity. Basically if you can build a regular house on your soil, you can
certainly build a dome.
Because of the reduced surface area of a dome and its thin shell construction, our domes weigh less than the average house, but are remarkably stronger than other types of structures. Our domes are considerably lighter than a concrete block house. A 30’ about 31,000 lbs, 34’ about 33,000 lbs, 40’ about 39,000 lbs, a 45’ about 44,000 lbs, a 48’ about 46,000 lbs. You do not have to build the dome on a certain type foundation. If your neighbors needed a soil sample before they could build their conventional house then you may need it too. Or unless you feel something abnormal, ask your Builder or neighbors if need be. Domes require no more than a conventional house.
Q:
In my area I have to deal with the
possibility of a wave surge, can I build my dome on "break away basement walls"?
A:
Yes. If you
have to design with the possibility of a wave surge, you may be able to enclose
the first floor pilings with breakaway walls. Breakaway walls are nonstructural
walls that will break-a-way in the event of a wave surge. Pilings (columns)
would support the structure and the breakaway walls could be installed between
the pilings to enclose the ground floor. The purpose is to enclose the ground
floor but preserve the house if a wave tears down the walls.
Q:
In my area I have to build on pilings
and a platform. Can the dome be built on pilings and still maintain its
structural integrity?
A:
Yes, building our dome upon pilings does not effect the dome's structural
integrity. We
can design the pilings, but you will need an engineer licensed for your state to
seal the Piling Blueprints. For example, the Building Plans Cost for the pilings and concrete
platform for a 45' dome would be about $800-$1,000. We know of a Florida
engineer who charges from $1,000 to $2,000 to seal the pilings and platform
plan. If you built the dome on the ground the plans would only be about $500
and the engineering would be about $500. All the costs associated with
elevating any house onto pilings is considerable more and worth considering
other options.
Q:
Can I berm or backfill dirt up
around the outside of my dome?
A:
Our dome lends itself very well to berming because of the strength of the dome
shape and the totally concrete exterior wall, with no materials to rot. Our
domes have been bermed with as much as eight feet of backfill. However, if you
earth berm your dome, we recommend a drain system to drain the water away from
the foundation. Plans for this drain system are included with our basement plans.
Our dome can be bermed higher, but we do not recommend it because of the additional expense of labor and the extra concrete required. A dome or a structure that is not buried would never have to withstand loads greater than 100 lbs. per sq.ft. If a structure is buried, the earth could put loads in excess of 500 lbs. per sq.ft. We do not design our standard dome for these extreme conditions that would not normally occur. If you plan to earth-berm your dome advise us when ordering your plans so we can advise you if there are any modifications needed on the dome.
We have not had any of our domes completely earth covered. What do you want to accomplish by covering the dome with earth? There may be a better way than covering the dome.
Q:
If I use the Shell Consultant to
supervise the assembly of my dome shell, when will he arrive at my construction site?
A:
Typically after the foundation is finished. It
has been our experience due to delays with building departments and slab
subcontractors, no project ever starts on time. As a result, at the point when
you have the building permit and the slab is formed up and ready to be poured
within a few days, we will determine which consultant is available.
