This describes a whole class of systems that employ
modular insulated forms into which rebar is threaded and concrete is
poured to created an isulated monolithic wall structure. Contractors
love these systems because the forms are generally very fast and easy
to assemble, the concrete can be pumped into the forms virtually any
time of the year because the cement is insulated as is cures, and the
result is a very strong, durable, insect and fire proof, and fairly
well-insulated wall. This method of building is definitely gaining popularity,
judging by the multitude of systems that are on the market.
The various modules are assembled more or less like lego toys, where one units locks into the others around it in some way. Mostly they are made out of Expanded Polystyrene (EPS) reinforced with steel or plastic ties. Some are made of EPS that has been recycled and then glued back together with cement. Some of them are made out of mineralized sawdust or wood chips bound with cement. Most of these are in block form, but some are available as panels or planks. Many of them are billed as "green" or environmentally friendly, either because of the recycled content or because of the thermal properties of the wall. They definitely reduce the use of milled lumber in building a house, which is good.
My main objection to these approaches to building, besides the fact that they utilize massive amounts of manufactured insulation, steel and cement, is that the structure of the wall itself does not provide optimal placement of insulation and thermal mass. Ideally you want most of the thermal mass of the building to be on the inside where it can absorb the heat provided, and stabilize the interior temperature. This mass should then be well insulated from the outside air. With most ICF systems the mass (concrete and steel) is embedded within the insulation in the finished wall, where it helps stabilize the fluctuations of temperature somewhat, but also does bleed energy to the outside. A couple of inches of Styrofoam is not sufficient insulation for the thermal mass from the outside, and the insulation of the inside prevents the mass from doing its job efficiently. Reports of the the overall insulation of these ICF systems vary widely, but typical R values are right around R-20. When compared to the R-40 attained with straw bale or earthbag/volcanic rock walls, this is not so great.
I think the greatest value of these ICF systems might be in creating insulated foundations or stem walls for other methods of building that require such foundations.
Listed below are some links related to ICF systems
that I found when searching the web:
To see some photos of an interesting home designed for high energy efficiency built partly with SIPs see helios-homes.com
This system for forming concrete is a hybrid of standard forms and ICF's. It offers the tremendous advantage of placing the concrete mass on the inside of the building shell, where it can do the work of moderating temperatures effectively. The outside of the form is composed of 4 inches of EPS insulation, with ties that remain to attach to the exterior siding. The company that manufactures this system is in Canada. For more information, you can check out their website: thermalwall.com .
This unique wall system, manufactured by allwallsystem. CFIs are forms for poured concrete walls that stay in place as a permanent part of the wall assembly. The forms consist of concrete board on the inside and out held together by galvanized steel studs every 7.25 inches with 4" of rigid insulating material held by 1" spacers in the center. The forms have window and door openings pre-cut as well as electrical conduit and boxes installed. Red iron steel (rebar) runs vertically from every slab every 4' and horizontally in the tie beam area, then the form is braced and poured full of concrete. The poured concrete creates a "post and beam system" including a continuous tie beam along the top, as well as walls 1" thick solid concrete next to each concrete board surface.
Once the forms are poured, the walls are ready for conventional drywall finishing on the inside, and any conventional finish such as stucco or siding. Electrical conduit boxes are already in place for the electrician as well. This unique combination of steel studs, cement board, rebar and poured concrete creates a wall of great strength, reasonable insulation (R- 20), low air infiltration and good thermal mass.
The Concrete House: Building Solid, Safe & Efficient with Insulating Concrete Forms by Pieter VanderWerf, 2007. Prospective homeowners will welcome this introduction to a durable, energy-efficient new building technology: insulating concrete forms (ICFs). Written by a top expert in the field, and organized in an accessible question-and-answer form, it will help homebuyers decide whether an ICF is right for them and how to get the most for their money. Every aspect of planning and construction is covered, from exactly what an ICF is to the intricacies of building a concrete house, from choosing a contractor to selecting a suitable design for the system. There's crucial advice on how to make sure construction goes smoothly, diagrams and photos to illustrate every point, beautiful ICF homes on display, and explanations of how these homes differ from conventional ones and why they cost less to maintain.
Insulating Concrete Forms for Residential Design and Construction by Pieter A. Vanderwerf , Stephen J. Feige , Paula Chammas , Lionel A. Lemay, 1997. Insulating concrete forms (ICFs) are hollow units made of plastic foam, assembled into the shape of a building's exterior, and filled with reinforced concrete to create structural walls. This step-by-step guide will introduce you to the advantages of ICFs, and show you how to incorporate them successfully into your homebuilding projects. Featuring a helpful eight-page color insert, the book offers you full coverage of ICF components, design issues, engineering, assembly, and much more.
Insulating Concrete Forms Construction : Demand, Evaluation, & Technical Practice by Ivan S Panushev, Pieter A. Vanderwerf, 2004. Guide to construction methods, providing the business and technical facts needed to make pro or con decisions about ICFs. Covers construction process details, including plumbing and electricity; comparisons of ICFs in commercial and residential construction; getting a good ICF crew; and more. Supported by the Insulating Concrete Form Association. For construction contractors.
Insulating Concrete Forms Construction Manual by Peter A. Vanderwerf, W. Keith Munsell, 1995. Insulated concrete forming systems (ICFs) provide many benefits to both contractors and homeowners. Hidden from view under sheetrock and siding, ICFs offer low labor costs; are easy to install; and are durable, energy-efficient, fire-safe, and virtually soundproof. Homes built with these systems look like any other, but under the standard covering lie solid, built-to-last concrete walls. Endorsed by the Portland Cement Association, this concise handbook gives contractors the hands-on information they need to use ICFs in the field. Authors Peter A. VanderWerf and W. Keith Munsell describe how these systems work, how to train crews to install them cost-effectively, and where to order product.
Making Better Concrete: Guidelines to Using Fly Ash for Higher Quality, Eco-Friendly Structures, by Bruce King, 2005. "This is the best and most readable 'how to' guide for using high fly ash concrete -- highly recommended. Using high fly ash concrete is a win-win-win solution: It makes better concrete, costs less, and has a greater environmental benefit than almost any other primary building material out there."-- Scott Shell, Architect, EHDD Architects
"At last, a practical guide on HVFAC written for engineers and contractors alike. When it's available, our company will want to buy 25 copies or so to distruibute to our Foremen, Superintendents and Project Managers. While we have been placing HVFAC almost exclusively for the last five years on all of our projects, we have had to rely on our leadership in the field to educate and to pass on their experience by word of mouth and by their example. Now, if they read the book, our men will also understand why HVFAC is such a great technology now and for the future of our planet."-- Deva Rajan, Founder, Canyon Construction
"This is an excellent and informative primer on recent developments in high performance fly ash concrete. The "win-win" use of a plentiful man-made waste product to economically obtain better concrete benefits clients, engineers, and the global environment."-- Mason Walters, Structural Engineer and Principal, Forell/Elsesser
romanconcrete.com links to an article about "Roman concrete" and its similarity to concrete with fly ash.
Concrete Systems for Homes and Low-Rise Construction by Portland Cement Association, 2005. Fast gaining on more traditional homebuilding materials, concrete systems save builders time, money, and headaches. Offering durability, cost savings, energy efficiency, and eye-pleasing aesthetics, concrete systems now account for large shares of the walls, floors, roofs, finishes, and landscape products in small buildings in the United States. But are concrete systems right for you and your construction crew? And if so, which ones? This is the place to find out. Written by experts from the Portland Cement Association, Concrete Systems for Homes & Low-Rise Construction provides expert, straightforward answers on concrete systems. Open these pages for everything you want to know about availability of products, evaluating concrete systems for homes and low-rise buildings, requirements for application, managing projects, and much more. Based on case histories, field research, and hands-on-the-hammer experience, and with more than 325 photos and illustrations, this one-stop resource shows and tells what you want to know. It's a huge time and money saver!
Solar Hybrid Home
Basement: 603 s.f.
Rooms include: Master bedroom, bath, second bedroom , sundeck, gallery/hall, and open lofted space that could be converted to an additional room.
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