INSULATED CONCRETE FORMS
|INSULATED CONCRETE FORMS
Daniel R. Gauthier Insulated Concrete Form Construction Consultant
What are insulated concrete forms (ICF’s)? This is the strongest and most thermal efficient method of construction
ICF walls are constructed of a stay-in-place insulating concrete forming system that consists of individual lightweight
blocks, available in different shapes and sizes to accommodate any size or shape of building and/or design
requirements, even round structures such as swimming pools and storage tanks. Each hollow block is made of two
pieces of expanded polystyrene (Styrofoam) held together with plastic ties. The foam blocks are stacked like (lego)
building blocks, aligned, braced, strengthened with steel reinforcement (1/2” rebar) and filled with concrete (3000
PSI). The resulting wall is a solid, continuous (monolithic pour), airtight, steel reinforced concrete wall surrounded by
several inches of insulation. The forms stay in place after the concrete cures, allowing the concrete to cure to a much
greater strength than the concrete in removable forms and providing interior and exterior insulation. The embedded
plastic ties (usually 6” or 8” on center) have flanges on both sides to create fastening strips (usually 1” wide) for the
installation of interior and exterior finishes. Drywall or other interior finishes can be alpplied directly to most ICF’s.
Brick, stone, vinyl or wood siding can be attached directly to the forms, as well as stucco finishes for the exterior.
ICF’s are excellent for residential and commercial construction. At first ICF’s were used primarily for basement walls
and foundations underneath wood frame construction. Gradually, as people began to understand the true benefits of
ICF construction, ICF’s were increasingly used for above-grade residential and light commercial buildings. Now ICF
construction is being used in the construction of high rise buildings, using ICF’s for in-fill exterior walls between the
floors and interior walls for safety, security, sound and humidity control in designated areas. With the increasing cost
of energy, ICF’s have become the #1 choice of builders that are interested in delivering the most energy conscious
structures available. These are the homes and buildings that will be worth the most in the future.
ICF’s possess the following benefits:
ENERGY EFFICIENCY: This is by far the greatest monetary benefit to building with ICF’s. While ICF walls provide
an excellent environment for basements, the full benefits of ICF walls are gained when used for the entire structure,
above and below grade. ICF walls create a solid, continuous wall that blocks air infiltration, drafts, cold spots and wide
temperature fluctuations. The ICF walls provide a high R-value, very low infiltration of air and thermal mass that keeps
temperature nearly constant throughout the year. As a result, heating and cooling units work far less to condition the
inside air. The savings realized on heating and cooling costs can be more than 50%.
CLEAN AIR: ICF construction is so tight that most manufacturers recommend using an air exchanger in conjunction
with the HVAC systems. In blower door tests conducted by Reward Wall Systems, an ICF home tested at 0.0379 air
changes per hour. Because so much unfiltered air leaks into a wood frame house, the interior air of a new wood frame
house changes completely .5 times per hour. Contrary to popular belief, it is easiestr to control indoor air quality in a
tight home. The air exchanger continually pumps fresh, filtered clean air into the heating and cooling system keeping
the interior environment clean and comfortable throughout the house. This also means that the interior air in an ICF
structure is virtually free of dust, pollen, and other allergens.
SOUND ABATEMENT: ICF’s are great to use in high-noise areas. Solid concrete walls with several inches of
Styrofoam insulation make for quiet buildings. Riverband Acoustical Laboratories of ITT Research Institute in Geneva,
Ill., conducted sound transmission loss tests on 11-inch thick ICF wall (5” of Styrofoam (2 ½ in. both sides) + 6” of
concrete and rebar) with ½“ drywall on both sides. A 7,400-pound sample wall was constructed in the lab’s test frame
and allowed to cure for 31 days. The test consisted of transmitting sound ranging from soft to loud in volume.
Instruments on one side of the wall then detected how much sound got through to the other side of the wall. The wall
measured a transmission loss of 49 dB according to the limits set by the ASTM Standard E90-7, thus giving the wall a
sound transmission class rating of 49. By comparison, a 2x6 wood frame wall filled with fiberglass insulation and with
½” drywall on both sides has a sound transmission class of 36. A sound transmission class of 50 is cannot be heard.
SAFETY: Because the concrete in ICF steel-reinforced concrete walls cure to a strength much stronger than
conventionally poured concrete, ICF’s are the strongest walls available when it comes being assaulted by the
elements. In fact, ICF buildings have survived intact after being hit by tornadoes with winds up to 250 mph. They have
survived car crashes and are even BULLET PROOF! ICF’s are ideal to use in extreme climates of both HOT and
COLD and in most cases the cost is 2%-5% more than wood construction, but when the energy factor is considered
(50% savings over wood), it’s truly the best bargain available.
The greatest danger during a hurricane or tornado is flying debris. Researchers at the Wind Engineering Research
Center at Texas University, in conjunction with the Portland Cement Association, compared the impact resistance of
ICF walls to conventional wood frame walls. Testers used a compressed air cannon to shoot a 2x4 wood stud
traveling at 100 mph straight at the walls. This is equivalent to the weight and speed of debris generated during a
tornado with 250 mph winds. The missile easily passed through the wood frame wall, not slowing in speed and no
damage to the 2x4 missile. However, when shot at the ICF wall, the missile not only failed to penetrate the wall, it
completely shattered and did no damage to the concrete. If you live in a tornado prone area, there is no choice but to
build new or re-build with ICF’s.
Fire Safety is another benefit to ICF construction. Most ICF walls carry at least a 2 hour fire rating required by most
codes, but some ICF walls have been tested to 3 or even 4 hour ratings. I have seen pictures of ICF structures that
have survived wild fires with the super-structure still in tact.
During the past few years ICF’s have proven to be the wisest choice in reducing the future cost of energy. Many
homes are now being built as “zero-energy”, meaning that they produce enough of their own energy to stay off the
My name is Daniel R Gauthier. I am an insulated concrete form construction consultant. I have been in the building and
survey business for over 25 years (Registered Land Surveyor in R.I. from 1976-2002). I now live in West Hartford, CT.
in a home that I built in the year 2000. This house features handicap design and one-floor living with about 4000 S.F.
of living area including a 14' x 38' indoor pool built entirely of insulated concrete forms. My experience of living in this
home has led me to only one conclusion. I WILL NEVER LIVE IN ANY HOUSE NOT BUILT WITH INSULATED
This is the strongest, quietest, most thermal efficient method of construction available today, and all for about the same
price of wood frame construction. Below grade, above grade or multi-story, these block will conform to any size or
shape, even round walls. Any style of siding can be applied directly to the exterior of the block and sheetrock can be
applied directly to the face of the block on the inside. Structural integrity is unquestionable with 6” poured in place,
reinforced concrete walls, designed to withstand 140mph wind. 2 ½” of styrofoam on both the inside and outside wall
provide maximum thermal insulation. With the spiraling cost of energy today and the certain rise in cost in the future,
there is no alternative than to build the most energy efficient home possible. These are the homes that will be the most
valuable in the future.
As an insulated concrete form construction consultant I can be as involved or uninvolved with the project as the client
needs, therefore I offer the following schedule of options. If a client needs survey services, septic system design,
sewer design, plot plan or layout, I can make the arrangements. I offer a plan service, which may include handicap
design, one-floor living , maximum energy efficiency and walls dimensioned to fit the block. Existing plans can be
modified slightly to fit the block dimensions (for ease of insulation and less waste) or specific dimensions can be met,
but block will have to be cut in the field. Any floor plan or exterior design can be incorporated into the floor plans.
Trussed floor systems and trussed roof systems are recommended and typically used. Please visit the following
website for a gallery of recently completed job sites: https:.//picasaweb.google.com/m/viewer?
fgl=true&pli=1#album/688967777/543441451259910094 Please visit the following websites for general information:
http://concretehomes.com or http://greenbuildingtalk.com
For further information or if you have any questions or to arrange for a free estimate please call me (860) 416-3466.
Thank you for your consideration,Daniel R. Gauthier