Welcome Home Buyers and Owners/Builders!
You have come to expect more from your new home. You want beauty, functionality, value, quality and security. Additionally you expect lower maintenance and utility bills while offering a healthier living environment for your family –these are all attainable, in fact, why not have them all?
What Are ICFs?
Insulated concrete forms are hollow polystyrene blocks that are stacked into the exterior walls of a building, reinforced with steel rebar and then filled with concrete. The resulting wall system provides exceptional strength, energy efficiency, noise reduction and an overall level of comfort you won’t find in a traditionally built structure.
Not All Homes Are Created Equal…
Homes built with Greenblock Insulated Concrete Forms may look like any other ordinary house from the outside, but look beneath the surface and you’ll see that our walls are far superior to conventional construction methods.
Extremely Energy Efficient
A Greenblock ICF wall provides a consistent R-24 Thermal Resistance over the life of the product. Coupled with the thermal mass characteristics of concrete, as well as the absence of air infiltration in an ICF wall, the Greenblock 6” ICF provides a wall system comparable to that of an R-50 wood-framed wall. Also, uncomfortable “cold spots” are reduced by eliminating thermal bridging. According to recent documented tests, ICFs are up to 70% less expensive to heat and 50% less expensive to cool than traditional wood frame construction. For more information on R-Values, click here.
Safe – Strength that Stands Up to Mother Nature
Greenblock walls offer protection from extreme weather events like hurricanes and tornadoes. They resist cracking and buckling because they are built with steel reinforced concrete, the strongest building materials you can use. They also provide a 4-hour fire rating, compared to only a 15-minute rating for homes built from wood.
Texas Tech University researchers tested Greenblock ICF walls against CMU (Concrete Block) and Stick (Wood Frame with Brick veneer) walls. They shot a 15 pound 2×4 at each wall. At 120 mph, the 2×4 shattered when shot at the ICF wall. The same 2×4 completely penetrated the CMU wall at 60 mph and the Stick wall at 65 mph.
In many areas of the country homeowners pay extra (12%-18%) for impact resistant glass capable of withstanding hits from debris at 110-140 mph. Does it make sense to put these high performance windows in a 60-65 mph wall? Of course not; combining the impact glass with ICF walls provides the safest environment for your family. To read more about the flying debris test, click here.
Click here to read how the US Marines and 50 pounds of military grade TNT could not destroy an ICF wall.
Homes built with Greenblock Insulated Concrete Forms resist mold and mildew. Because of the insulation and thickness of the solid concrete core, condensation cannot occur in the wall. This prevents mold growth that can be problematic with Stick and Concrete Block construction. For more information on this topic click here.
Building in a noisy area? Our structures achieve documented levels of Sound Transmission Classifications (STC) 50 (inaudible) or higher. Wood frame structures typically rate an average of STC 25, meaning that voices can be heard outside the structure.
For more information on sound attenuation, click here to read the article in ICF Magazine.
Reduce the negative impact on the environment – through sustainable site-planning, energy efficiency, conservation of natural resources, lower air conditioning and heating requirements and improved indoor environmental air quality. Greenblock’s materials are non-toxic, contain no CFCs, HCFCs or formaldehydes, are nonnutritive to insects and rodents and do not support the growth of mold and mildew. The absence of “off-gassing” eliminates the possibility of any air pollution or ozone depletion.
Insulating concrete forms cost a little more up front— about 3% on average — than traditional 2×6 stick wall construction or concrete block construction. However, that additional investment is quickly recouped by the tremendous monthly savings in energy, interest, and insurance costs. When you add in the reduced maintenance costs and higher resell value of an ICF home you can see why a Greenblock home is actually more affordable than wood or concrete block construction.
“The expandable Polystyrene Foam used to make Insulated Concrete Form products is highly inert. It is not considered toxic by U.S. government agencies. It does not contain any formaldehyde. It has not been linked to any respiratory problems or skin irritation, as have some fiber-based insulations. Attempts to find any emissions from polystyrene foams used in walls, failed. No emissions could be detected by the most sensitive instruments. The EPS used in ICFs are formulated so that they do not burn by themselves. Extensive research on the polystyrene concluded that when they were forced to burn, their emissions were “no more toxic” than the emissions of burning wood”. Source: “Insulated Concrete Form Association (ICFA)”
ICF vs Wood Frame and Concrete for Residential Construction: An Independent Assessment
Insulated concrete forms (ICF’s) are changing the face of home building and construction. It used to be that you had limited options if you were building a new house. Conventional wood frame wall construction dominated the home building market. All of the building trades almost reached a point where they didn’t know how to do anything but wood frame walls when it came to building a new house.
You could get a house with all brick walls if you wanted one but even that became little more than a masonry facade over a wood frame construction core. The need for high wall insulation for heating and cooling made it impractical to have an all brick house without insulation so the all brick house ended up evolving into a wood frame building with a brick veneer or facade.
All concrete houses were simply ugly 40 years ago. The building trades didn’t really have many cost effective options for finishing off the outside of a concrete wall so it ended up bare or painted. The look became popular with office and government buildings but it was terrible for homes. And of course the problem with insulation was just as bad with concrete walls as it was with brick walls.
All of that has now changed with the invention of ICF’s. The concept is really very simple. An ICF combines a conventional reinforced concrete wall with modern rigid foam insulation and does so in a way that is labor and material efficient and cost effective. Most ICF’s today are made up of 3 basic parts. The first part is the inner layer of rigid foam insulation. Each piece is usually 2 to 3 inches thick, 30 to 40 inches long and 12 to 16 inches high. You cut and interlock as many pieces as you need to form the inside of the wall. The second part is the outer layer of foam. Usually it is identical to the inner layer of foam but many companies now have provision on the outside for attaching vinyl or wood siding or some other outside house finish. The third part to the system are wire or plastic connectors that connect the outer foam to the inner foam with a 4 to 12 inch gap in between for pouring the reinforced concrete wall. So when the wall is done you end up with a sandwich of 3 layers; Rigid foam insulation, then reinforced concrete wall and then another layer of rigid foam insulation. Because of the connectors, the foam becomes a permanent part of the wall and building.
With old-fashioned concrete walls you had to construct a form to hold the concrete in place while it cured and then remove the form after the concrete was hard. A lot of work was involved and you ended up with a wall that was strong but had almost no insulation value. But with ICF’s the foam does four things all at once. It acts as the form for the concrete, insulates the wall, forms a vapor barrier for the wall and also acts as an excellent surface for attaching inside and outside final finishes. It goes in easy and you don’t remove it when the concrete is cured. You can use ICF’s from the footings of a building all the way up to the roof. You end up with a building wall that is superior in almost every way. Much stronger walls, magnificent sound barrier and thermal mass advantages, easier to heat and cool and no wood to rot and grow mold are all powerful advantages of ICF construction. Because the outside siding options are the same with either ICF’s or conventional wood frame construction your home will fit into the neighborhood perfectly. From the outside the only thing that would look different is the walls are thicker compared to a wood frame building.
Your Independent Building guide.