Friday, September 4, 2009

ICF - Insulated Concrete Forms - Method of Building Walls

There are several different methods used to build walls. This article will discuss the ICF method. We will look at the materials used in this method and then list the conclusions reached based on these materials. If you are standing inside the house, we will talk about the materials from the inside of the house to the outside of the house.

Gypsum Wall Board - this material absorbs water. The moist Gypsum wallboard can contribute to mold and mildew.

EPS foam - very good insulation properties. It is 'continuous and touching' which provides excellent energy savings.

Concrete - this material is poured in what is known as a 'continuous pour'. Even if the concrete is poured in lifts, the adhesive properties of concrete to itself allow the pour to be considered continuous. This material that goes from free flowing to rock solid is what provides the best-sealed envelope of a home.

EPS foam - very good insulation properties. It is 'continuous and touching' which provides excellent energy savings.

Cementious Finish - typically a fiber mesh wrap is applied to the walls and synthetic stucco materials are installed in two applications to get the requested look by the homebuyer.

Windows and Door openings - typically the openings are formed with 2x12's cut down to the width of the foam blocks and braced to accept the concrete pour. The 2x's are fastened with J-bolts that are placed prior to the concrete pour. An issue with the openings is that they have wood in the exterior walls in the areas where water has the highest possibility to enter the house. This creates the possibility, and likelihood, of water entering at these locations (the same as a wood framed house.) Remember, when the air is flowing thru the return air it is pressurizing the air which means 'additional air' has to come in the house. The window and door areas are where this air will come from, which allows water to get further into the wall, into the wood 2x bucks and farther away from the edges. This makes it take longer for the moisture to get out. When this occurs this will lead to the formation of mold and mildew.

Ease of construction - the trained skill level to build the walls of a custom home are similar to the skill level needed to build a concrete block home, or for a skilled carpenter to build a wood framed home.

Issues during construction - typical issues are proper bracing to minimize/eliminate concrete spills (blowouts) and bracing to keep the walls plumb (vertically aligned) and straight along the top of the forms.

The ORNL (Oak Ridge National Laboratory, contracted by the United States Department of Energy) after testing all 16 methods of construction proves the method of construction that Insulated Concrete Forms (ICF) utilizes is the second best method of building a home (by approximately 9% less savings) in regards to energy savings. To confirm please view: http://www.ornl.gov/roofs+walls/research/detailed_papers/thermal/index.html

The ICF method exceeds all building codes for high wind resistance due to the use of poured-in-place concrete in the forms.

This article has discussed the ICF method of building walls. It has described the various materials that are used. This article has also shown the problems and benefits that each of these materials can cause when building a house. The use of the ICF method of building walls only fails in 2 areas of building a home to prevent mold and mildew issues, which is the use of wood around openings and the use of a gypsum product (drywall) on the interior of the exterior wall. The 2 inches of foam and the drywall board on the interior is what accounts for the 9% higher use of energy than a wall with concrete in direct contact with the interior, such as the most energy efficient wall that utilizes the method referenced by the ORNL as concrete- insulation - concrete (CIC).

Are you getting ready to build a new home? Are you trying to build an energy efficient home? To get more information about building your next energy efficient home, visit http://www.allwallsystem.com, a "CIC" method of building.

1 comment:

Smaug the Golden said...

Hi, I just came across your article on ICF insulated concrete and I wanted to get your input on "spray foam insulation" versus "ICF."