ICF General Design Guidance
ICF General Design Guidance
(OP)
Looking to get into ICF construction design; looking for any recommendations on good books, design guides, websites/organizations for design & detailing. Also interested in any advice in this area i.e. pro's/con's, pitfalls, etc. Thank you






RE: ICF General Design Guidance
Dik
RE: ICF General Design Guidance
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: ICF General Design Guidance
Structural Design of Insulating Concrete Form Walls in Residential Construction, and
Prescriptive Method for Insulating Concrete Forms in Residential Construction
They are published by NAHB Research Centre, Inc. Upper Marlboro Maryland.
Dik
RE: ICF General Design Guidance
RE: ICF General Design Guidance
In PDF: http://members.cement.org/EBiz50/ProductCatalog/Pr...
or print: http://members.cement.org/EBiz50/ProductCatalog/Pr...
ACI 560 is looking to have their design guide ready for public comment by Spring 2013. We will have training sessions once that is in print. ACI 560 will also have sessions at next fall's ACI convention in Phoenix.
http://www.cement.org/homes/
As far as pitfalls, the main one is trying to construct these without having proper training. Most manufacturers offer training at low or no cost. My first ICF course was as a builder and designer about 12 years ago, from ARXX. Each ICF brand has its quirks and tricks, so best to pick one to start and stick with it until you understand it thoroughly. That said, I have chastised several ICF industry representatives for proclaiming the differences in using their product. With flat wall ICFs, there are differences, and attending to these in the design phase will improve economy, but ignoring them with an experienced builder on the project is not a real problem. The biggest issue is to find out before design which system you plan to use, so you account for block sizes and things like foam thickness. Otherwise, you may end up with inefficient use of ICF blocks (like having to cut 8 inches off the height) or need to revise cladding and other details (particularly around windows and doors.)
Contact local contractors (look on manufacturer's website for these) and identify one or two brands and builders. Then, get familiar with the mfg design instructions, which cover things like block sizes, coursing, corners, and concrete and foam thickness. Stick with flat wall systems for now. The waffle and screen grid systems are more complicated for design and construction, and the amount of concrete you will save is usually of little importance on most small buildings, everything else considered. Don't be afraid to use more reinforcement (what did you expect me to say) located in the middle of the block. Don't over economize concrete and steel when doing so complicates the layout or design. The formwork is the place to economize. Also, keep in mind that the cost of conventional concrete building frames is 50% formwork (including labor), and about half of the remaining portion is labor. ICF's shift that equation toward less labor, since setting forms and placing reinforcement is much easier and faster.
RE: ICF General Design Guidance
RE: ICF General Design Guidance
If the wall just has horizontal form ties between the foam forms - no problems with the analysis both for bearing, bending and shear.
However, if the wall section is a honeycomb structure, approaching a Vierendiel (sp... sorry) truss configuration, as a couple I have seen, the analysis is not so straight forward, mostly in shear. In this circumstance, I had to be conservative and use an unreinforced concrete section for shear as there is really no shear reinforcing in the wall. A tested wall would probably have given much greater shear capacity.
It is also an interesting fact here that between the honeycombs, the form material has to permanently span between the vertical nd horizintal concrete sections to resist any lateral soil loads, and the form material, as previously mentioned, is NOT a recognized structural material, in either the IRC or IBC. Go figure...
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: ICF General Design Guidance
Did two designs: The first was in reinforced mud! There are actually some pretty good designs and construction of these structures in the old Zone 4 areas. The execution of the project really depended upon the specialty contractor. But he decided to go to Africa and we did the project again with the Arxx system.
I like the old W-Panels (or Impact or Insteel or wire mesh welded cages with an inch of foam and 7/8" of high strength stucco on each side) Our firm first came across these in Nigeria but found out that they were being manufactured in Chino, California. Apparently you could design them as folded plates and span long distances or, we understand, they were used on high walls on a project in Saudi Arabia, providing the folding design with the panels about three inches thick. Very easy to install and we used plastering pumps instead of shotcrete.
RE: ICF General Design Guidance
RE: ICF General Design Guidance
Some of the earlier systems had block with foam exterior faces and some portions that formed partial height webs, so the block was an total rigid foam block made from EPS foam.
The volume and bulk of the block including the voids made shipping costly and pests/vermin could tunnel through the foam connection portions eventually.
Since then, the flat plate faced systems with different type ties of varying lengths (for different wall thicknesses) have become more common and are more popular as long as they are braced adequately to prevent "blow-outs" when placing the concrete. The use of pumps to economically pour an entire foundation in lifts over time to decrease pressures, shifting and deflecting around openings or at corners.
Someday, they will universally use more the rigid and better insulation available with XPS foam.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
RE: ICF General Design Guidance
RE: ICF General Design Guidance