Concrete Slab - Standard for Ai Dome

Concrete Slab - Standard for Ai Dome

45′ dome home linked to 34′ dome garage formed up slab being poured

Poured slab for 34′ dome linked to 45′ dome.

American Ingenuity’s stock building plans include drawings for a concrete slab foundation. Plans for raised wood floors or basements or pilings with platforms are available.  For a complete summary of the foundations that can be utilized with the American Ingenuity dome, click on Foundation Summary.

The dome’s standard footing size is 20″ tall by 16″ wide with slab 4″. Foundation should be built on undisturbed native soil or fill – with soil compacted to 98% density for a minimum of 2,000 psf of bearing pressure. If your bearing capacity is less, then the engineer can increase your footer size and slab thickness. For example the soil for a dome being built in California was 1,500 psf. Its footer was increased to  20’x20″ and slab was increased to 6″.

Ai can design a concrete stem 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, please call our office for pricing.  The garage dome would need a concrete slab.

How is the concrete slab insulated? As far as insulating the slab, it is the customer’s choice with some building departments not allowing the slab perimeter to be insulated. For example in Florida due to termites most areas will not allow perimeter insulation.. The insulating of the slab is listed on the building plans as an option. If the earth is cold then using 2″ thick E.P.S. would be beneficial.

Q: Are there any special requirements for the foundation?
A: The only thing unusual about Ai’s dome foundation is its shape. The multiple sided foundation is made up of flat sides to match the riser panels. Because Ai’s dome is lighter than most other buildings, it has less loading on the foundation. Reinforcing rebars connect the riser walls, entryway and first floor door dormer base panels to the foundation at the vertical seams.

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 15% at most 25%. 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.

Q: How deep will the footings be?
A: Ai’s standard footing for monolithic slab is 20″ tall by 16″ wide with 4″ concrete slab.  If there is a frost line, the footing depth is determined by the building department.   Also if your soil does not compact to 2,000 lbs per psf then your footer and slab thickness will be enlarged.

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 Portland Cement bag estimate to concrete the seams.