WHAT ARE ICF’S (Insulating Concrete Forms)

ICFs are hollow blocks or panels made of plastic foam that construction crews stack into the shape of the walls of a building. The workers then fill the center with reinforced concrete to create the structure.

The forms, made of foam insulation, are either pre-formed interlocking blocks or separate panels connected with plastic ties. The left-in-place forms not only provide a continuous insulation and sound barrier, but also a backing for drywall on the inside, and stucco, lap siding, or brick on the outside.

Although all ICFs are identical in principle, the various brands differ widely in the details of their shapes, cavities and component parts.

Block systems have the smallest individual units, ranging from 8" x 1'4" (height X length) to 1'4" x 4'. A typical ICF block is 10" in overall width, with a 6" cavity for the concrete. The units are factory-molded with special interlocking edges that allow them to fit together much like plastic children's blocks.

Panel systems have the largest units, ranging from roughly 1' x 8' to 4' x 12'. Their foam edges are flat, and interconnection requires attachment of a separate connector or "tie." Panels are assembled into units before setting in place - either on-site or by the local distributor prior to delivery.

Plank systems are similar to panel systems, but generally use smaller faces of foam, ranging in height from 8" to 12"and in width from 4' to 8' . The major difference between planks and panels is assembly. The foam planks are outfitted with ties as part of the setting sequence, rather than being pre-assembled into units.

Within these broad categories of ICFs, individual brands vary in their cavity design. "Flat wall" systems yield a continuous thickness of concrete, like a conventional poured wall. "Grid wall" systems have a waffle pattern where the concrete is thicker at some points than others. "Post and beam" systems have widely spaced horizontal and vertical columns of concrete which are completely encapsulated in foam. Whatever the differences among ICF brands, all major ICF systems are engineer-designed, code-accepted, and field-proven.

BENEFITS TO HOME OWNERS

Comfort - Houses built with ICF walls have a much more even temperature throughout the day and night. They have virtually no “cold spots”, and sharply fewer drafts.

Solidity - The rigidity of concrete construction reduces the flex in floors and cuts shifting and vibration from the force of the wind or the slamming of a door. Concrete houses survive high-force winds like hurricanes far better than wood homes. And when properly reinforced, they should also withstand earthquakes well.

Quietness - About one-sixth as much sound gets through an ICF wall compared with an ordinary frame wall. This sharply cuts the intrusion of noise from outside.

Energy efficiency - The superior insulation, air tightness, and mass of the walls cut the amount of energy needed for heating and cooling by 30-40%. This can save $200-300 per year in a typical home. In addition, it allows the installation of smaller heating and cooling equipment. That can reduce the initial cost of a house by over a thousand dollars.

Design flexibility - ICF houses can be completed with almost any interior and exterior finishes and can take any shape as easily as wood frame. In fact, some interesting effects, such as curved walls and frequent corners, can be less expensive to build into an ICF home.

BENEFITS TO BUILDERS

Versatile System - Flexible Designs
ICF homes can be designed in any style, and will accept any traditional exterior finish including vinyl or wood siding, stucco and brick. Because custom angles and curves are easily created, it's simple to build in bows, bays and radiuses. ICF systems accommodate any of today's most popular design features, such as tall walls, large openings, long floor spans, and cathedral ceilings.

Internationally Proven & Code-Accepted
Originally developed in Europe (where concrete home building is standard) ICF Systems have been used successfully around the world for more than 30 years. Thousands of ICF homes have been built in recent years throughout the United States and Canada. They have proven successful in every region and climate, from Orlando to Calgary. ICF systems are accepted by all the major model codes in the U.S., and by the R-2000 program in Canada.

Fast to Learn & Easy to Use
Although it looks new and different, anyone with construction experience can quickly get up to speed with ICF’s. An ideal crew has a mix of concrete placement and carpentry experience. Once the crew has some practice, each ICF built home requires less skilled labor and less total labor than a wood-framed home. ICF’s are very lightweight, so crews stay fresh through the day. Likewise, ICF’s present no problem for the sub-contractors who come after the walls are poured. Since holes, chases, and rectangles are easily cut into ICF’s with a knife or saw, installation of mechanical systems is a snap. The fastening of drywall and lap siding is just as fast and easy. And mid-course corrections, such as moving an opening, are no big deal - just saw it out and reform. It’s not more difficult to make changes to an ICF wall - it’s just different.

Cost Competitive
Over the last ten years, concrete priced have been remarkably stable. Recent price increases in other materials have generated interest in concrete building systems as never before. Labor savings and readily available materials make ICF’s, feature for feature, one of the most cost competitive wall systems in U.S. and Canadian housing markets.

Information on this page obtained from the Insulating Concrete Form Association.