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Basics of Insulated Concrete Form Construction

I found this information at while researching alternative construction for housing... it kinda breaks down different types with basic info. I edited it a little. This first deals with Insulated Concrete Forms (foam blocks):

Insulated Concrete Forms
This increasingly popular construction method relies on concrete and recycled plastic for its structural integrity and excellent insulation values. It is most popular in areas where lumber prices are high, due to the absence of big local forests - areas such as the desert Southwest, the Great Plains and southern California. But it's readily adaptable to just about any terrain, climate and location. Moreover, it offers an alternative building method with few practical disadvantages. Each manufacturer of concrete-filled foam blocks has its own method of making the basic building material. But to one extent or another, they all make their blocks out of a high percentage of recycled polystyrene, which is an excellent insulator against heat, cold, sound and critters. The blocks are reminiscent of old-fashioned cinder blocks because they are hollowed out in the center. But because the basic building material is so light, the blocks can be, and often are, much bigger than cinder blocks, sometimes several feet in length and width. They are either glued together or manufactured so that they interlock. Once together, the blocks create a honeycomb of tunnel-like air spaces inside a wall cavity. The spaces usually run both vertically and horizontally. Steel reinforcing bars are then located in the vertical floor-to-ceiling cavity. Then a special mixture of concrete is pumped into wall cavities, where a vibrating tool drives out all the excess air, making certain the cavities are filled to capacity. When the concrete hardens, the wall is essentially complete, with concrete and iron on the inside and polystyrene on the outside, offering an insulating R-value of about 32. The R-value of the standard 2x6-stud wall filled with fiberglass batting is 19. The nearly waterproof polystyrene surface is easily cut with a special knife, saw or router for the plumbing and wiring raceways. Obviously, window and door openings would be created before pouring the concrete. The rough openings usually include a wooden nailing surface for the finished doors and windows themselves. Interior walls are either plaster or standard drywall panels glued in place and finished as desired. Exterior walls are either stucco or siding glued in place. The biggest shortcoming in this construction method is cost. Even in areas of the country where plasterers and stucco masons are plentiful, a foam-block home will cost around 15 percent more to build than a comparable balloon-framed house. Where plasterers and stucco masons are scarce, the cost goes up even more. And if you opt for a siding like clapboards, cedar shingles and the like, the cost goes up even more because of the laborious preparations needed to give the rough exterior a reliable nailing surface. Of course, foam block advocates argue that energy savings over the years will compensate for the higher initial costs. But that's little comfort when you're writing those big monthly checks to cover the mortgage. Also, in rainy climates, the permeability of the foam blocks could allow water penetration or water buildup in the walls over time. Design considerations and more costly exterior siding options generally prevent the water problem from developing but again drive up costs.

Next: Straw Bale Construction

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