SD

ANADA

8230 Nessebar, District "Zapad-2", tel./fax 0554/ 46026, tel. 43135, e-mail: anada@abv.bg

Frequently Asked Questions on ECO-Block
(Insulating Concrete Forms Saving America's Energy)

Q: What are Insulating Concrete Forms?

A: Insulating Concrete Forms (ICFs) are hollow blocks or panels made of plastic foam that construction crews stack into the shape of the exterior walls of a home. Workers then add reinforcing steel and fill the gap (typically 4-8 inches) between the two layers of foam with concrete. This combination of concrete, steel, and foam creates a very strong and energy-efficient structure.

Q: How does the homeowner benefit from this type of construction?

A: Homes built with ICFs offer resistance to natural disasters such as tornadoes, hurricanes, earthquakes, fires, and floods. An ECO-Block home can dramatically reduce heating and cooling bills, as well as provide a comfortable and quiet indoor environment.

Q: What are the design possibilities and/or limitations with ECO-Block?

A: Today's concrete homes can be created with virtually any design or architectural feature. ECO-Block has furring strips every 8-inches imbedded in the panel to allow attachment of wood or aluminum siding, brick, stucco, and stone on the exterior, and drywall or plaster on the interior. The result is a home that looks like any other structure in the neighborhood but has all the benefits of solid concrete construction.

Q: Does it cost more to build this way?

A: Typically, a home built with ICFs will cost 2% to 5% more than a comparable wood-framed home. However, much or all of this up-front cost can be recouped through lower utility bills, insurance savings, and downsizing of heating and cooling equipment. An experienced ICF contractor may be able to further reduce the costs of construction. Resale is typically 10-15% higher.

Q: Is ECO-Block a difficult system for a builder to learn?

A: Conventional homebuilding crews adapt easily to ICF construction. Most of the work involved draws on standard carpentry skills and tools. The foam forms are lightweight, and power equipment moves the concrete.

Q: How much money can I expect to save on my utility bills?

A: A study commissioned by the Portland Cement Association concluded that homes built with ICF exterior walls require an estimated 44% less energy to heat and 32% less energy to cool than comparable wood-frame houses. This means that a typical 2,000-square-foot home in the U.S. will save approximately $200 in heating costs and $65 in air conditioning each year. The larger the house - the larger the potential savings. Some homes are realizing $1,000's per year in savings!

Q: How well do ECO-Block walls hold up in a fire?

A: Experience shows that concrete structures are far more likely to remain standing through fire than are structures built of other materials. Concrete does not break down until it is exposed to thousands of degrees Fahrenheit-far more than is present in the typical house fire. In "firewall" tests, ECO-Block walls were subjected to continuous gas flames and temperatures of up to 2,000 degrees Fahrenheit for as long as four hours.

None of the ICF walls ever failed structurally, in contrast to wood-frame walls, which typically collapse in an hour or less.

Q: What is the average R-value of ICF walls?

A: Walls made of ICFs perform, on an average, like a wood frame wall constructed for R-30 insulation. But that's not the whole story. The equivalent R-value performance of ICFs consists of three factors. First is the R-value of the expanded polystyrene. Second, the thermal stability of massive concrete walls reduces the temperature fluctuations, and, consequently, the heat load requirements, that are common to wood-frame buildings. Finally, air leakage (infiltration) can account for 20 to 40% of the heat load requirements of a wood-framed building. ICFs can reduce this air infiltration by 75%. As a result, with the combined performance of the R-Value of the expanded polystyrene, the stabilizing effects of the thermal mass of the concrete, and the reduced air infiltration, ICF walls actually perform as high as R-50 - or more in some areas of the country. 

Q: Won't the foam burn or give off harmful emissions?

A: The foams in ICFs are manufactured with flame-retardant additives. Tests using the "Steiner Tunnel Method" show that ICF foams allow only about one-fifth the flame spread of wood. The Southwest Research Institute reviewed the numerous existing studies of fire emissions and concluded that the emissions from polystyrene foams are no more toxic than those of wood.

Q: What about comfort?

A: Concrete walls built with ICFs effectively buffer a house's interior from the outdoors. The thick ICF sandwich of a massive material (concrete) with a light one (foam) sharply cuts fluctuations in temperature, air infiltration, and noise. ICFs keep the inside more comfortable and less drafty than ordinary wood-framed walls. With regard to noise, studies have shown that compared to a typical wood-frame house, only about one-third as much sound penetrates an ICF wall.

Q: How do ECO-Block homes resist tornado and hurricane-force winds?

A: Debris driven by high winds presents the greatest hazard to homeowners and their property during tornadoes and hurricanes. Recent laboratory testing at Texas Tech University compared the impact resistance of residential concrete wall construction to conventionally framed walls.

Only concrete wall systems, such as ICFs and concrete masonry, successfully demonstrated the strength and mass to resist the impact of wind-driven debris. The wood-frame walls failed to stop the penetration of airborne hazards.
Q: How popular is this building technique?

A: ICF construction continues to grow at an impressive rate. It is estimated that in 1998, nearly 20,000 homes in the U.S. were constructed with ICFs. It is anticipated that by the year 2003, more than 100,000 homes will be built annually with ICF exterior walls.

Q: Who can build ECO-Block homes in my area?

A: Virtually every part of the country now boasts ICF homebuilders. For information on finding a contractor in your area, contact your ECO-Block Regional Manager, the ECO-Block corporate office at 1-800-595-0820, or your local concrete promotion association.

Q: Is this building technique approved by code organizations?

A: Yes. Every major code organization in the U.S. and Canada has accepted this construction technique. ICF homebuilding has proven successful in every region and climate. The 2000 International Residential Code has a section on ICF construction.

Q: Can ECO-Block homes be built in earthquake areas?

A: Yes. If properly reinforced, an ICF home can provide significant protection during earthquakes. If you live in an earthquake zone, you should consult a structural engineer to determine what the reinforcement requirements are in your area.

Q: Why is ECO-Block considered an environmentally friendly method of building?

A: An average-size home built in the U.S. can save up to 41 trees if concrete products-such as ICF exterior walls-are used in place of wood products. Concrete is inert, non-toxic, and produced from abundant natural and recycled materials. A concrete home is durable and offers a significant reduction in energy usage.

Q: Is it difficult for subcontractors to work with this material?

A: No. Subcontractors-such as electricians, plumbers, and drywallers-can easily adapt to working in a house with ICF walls. Once they are familiar with the product, many trades people actually find it easier than working on a wood-frame home.

Q: Can ECO-Block be used for Tilt-Up applications?

A: Yes. The ECO-Block system for insulating tilt-up concrete panels offers the speed of tilt-up construction with the benefits of an ICF wall. After setting the panels in the form, install reinforcing and embeds, and place the concrete. Once the concrete achieves the specified strength, the wall is lifted in place and screw ties directly to the web system on the panel. For additional inch of concrete penetration, attach 1" extensions to the web.

Q: Can termites eat through the foam in an ECO-Block wall?

A: Expanded polystyrene (EPS) has no nutritive value to insects, including termites. If left exposed, and untreated they may attempt to nest in the EPS foam. Foam is approved for use below grade, as well as above grade by all building codes as long as "an approved method" of protecting the foam plastic and structure from termite damage is provided. Deciding what constitutes an approved method however is left to local code officials.

One measure agreed upon by all parties is the need for a minimum 6- inch bare concrete inspection strip at grade level. This is required if foam is used below grade or only above grade. This is extremely easy to accomplish with ECO-Block, since it is a panelized system. A six-inch horizontal strip of EPS is cut out to allow the formation of a solid concrete barrier at grade, see page 84 of the ECO-Block installation manual. This creates a solid concrete barrier, forcing the termite to the outside of the foam, where it is visible.

Additional steps together or separately, may meet the "approved method" requirements:

- Treat the foam with borate or termiticides prior to backfilling or covering.

- Install "bait systems" or treat the soil as usual.

- Treat footings and backfill with termiticides.

Eliminate as much wood in the structure as possible by using, steel, and plastic replacements, or treat with termiticides.

Remember, in a solid concrete home there is little to eat. The concrete also acts as a solid barrier to termite infestation inside the home. 

Q: Will it take longer to build my home with ECO-Block?

A: Experienced ICF crews report that building ICF homes can actually take less time than using wood-frame construction. The ICF construction method eliminates several steps-such as sheathing and insulating the exterior walls-that are necessary with wood-frame construction.

Q: Do I need an engineer to review my building plans?

A: It is always a good idea to have a qualified engineer review your final building plans. They will ensure that your construction project meets with local code requirements as well as ensuring proper design loads for hurricanes, earthquakes and other natural environmental conditions.

Q: Can radius and angled walls be constructed ECO-Block ICFs?

A: Radius walls are easily constructed by removing sections from the inside side panel and bending the ICF into the required shape. Similarly, any angle can be made by miter cutting the form at the proper angle and using foam to join the edges. Ninety-degree corners are manufactured to speed construction since they are the most commonly used corner angle.

Q: Can I leave ECO-Block exposed to ultraviolet rays for extended periods of time?

A: Exposure of up to a year should not pose a serious problem. However, a light oxidation layer will develop on the surface of the forms after extended periods of exposure. This oxidation does not indicate any detrimental effects to the wall form, however, if the proposed finish is to be a stucco (or other hard coat material), it is recommended that the oxidized layer be brushed away to provide a clean bonding surface for the stucco materials.

Q: When building with ECO-Block will mold and mildew in my new building be a problem?

A: Mold and mildew are not a problem when building with ECO-Block ICFs. Mold and mildew are fungi that grow in a moist atmosphere. They tend to form on the interior/exterior of walls where moisture condenses as a result of surface/air temperature differences. For example, interior warm air contacting relatively cool spots on a surface becomes colder, increases in relative humidity and condenses. Once the fungi forms, it can discolor the materials beneath it, deteriorate the materials' structures, and emit particles that cause unpleasant odors or affect the health of the building occupants.

The ECO-Block system will not allow condensation and resultant mold or mildew growth on either side of a wall as there are no thermal breaks in the wall; the inside wall remains at room temperature and the outside wall remains at the outside ambient temperature. The ECO-Block ICF forms the perfect air and thermal barrier.

Q: How can I obtain more information on the ECO-Block ICF building system?

A: Simply call us at our toll-free number, 1-800-595-0820 (in United States), 1-800-473-1066 (in Canada), or e-mail us at info@eco-block.com. You can also request information via our website, http://www.eco-block.com.

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