What is ICF?

icf_block_graphicConceived by engineers as a “perfect” building material

ICFs combine simplicity, strength, and energy efficiency

ICFs are basically stay-in-place forms for pouring concrete wall

ICF System Basics

  1. ICF Form System
  2. Wall Structure
  3. Insulation
  4. Air Barrier
  5. Vapor Barrier
  6. Interior and Exterior Finish Anchorage

History of Concrete Use and Development of ICF Technology

Historical Use of Concrete


pantheon_concrete_constructionThe Pantheon (125 AD)

One of Rome’s original structures used cast-in-place concrete. It has been in continuous use since the 7th century and is still the world’s largest un-reinforced concrete dome.

The Pantheon obviously did not have insulated forms, but has proven the strength and durability of poured-in-place concrete and that is the basis behind ICF.

 

lelandstanfordmuseumThe Leland Standford Jr. Museum (1894 AD)

The Leland Stanford Jr. Museum was one of the first projects in the U.S. to use “new” technology of cast-in-place concrete with reinforced steel as designed by Ernest L. Ransome, structural engineer.

Utilizing this innovative approach, the building was completed in two-thirds the time and at half the cost of an equivalent masonry building.

 

Development of Insulated Concrete Form Technology

  • Early ICFs first appeared in the late 1960s, with growth of concrete construction.
  • Imported from Europe in late 1970s to Canada.
  • The 1980s saw a number of different forming systems enter the market.
  • The 1990s saw a significant increase in ICF manufacturer’s bringing new systems to the market in the United States.
  • Increasing energy costs over the past ten years have encouraged rapid growth of ICFs in the United States.
  • The new millennium ushered in the next generation of insulated concrete forms.
  • ICFs have grown steadily in popularity as an alternative building system.

Broad Use of ICFs

  • ICF systems are in now in use worldwide
  • 45 current suppliers of ICF systems in the USA with 10 of these companies combine for over 90% of the total sales within the ICF industry.
  • Commercial use includes offices, hotels, schools, churches, hospitals, etc.
  • Used commonly in single and multi-family homes.

Basics of ICF Construction

ICF Wall Assembly

icf_wall_assembly_graphic

Insulated concrete forms consist of two panels of foam insulation made of expanded (EPS)  or extruded (XPS) polystyrene.

icf_stack_wallThe lego-like Styrofoam forms are easily assembled and lock together to create the wall.


Steel Reinforcing

icf_webThe reinforcing steel (rebar) is held in place by “webs”, usually manufactured from recycled plastic, nylon, or metal inserts, and becomes a permanent reinforcement of the wall.

icf_form_web_rebarHorizontal rebar is added as the blocks are stacked; vertical rebar is added pre-pour.


Window and Door Bucks

window_door_bucks2Window, door or other openings in the wall are pre-assembled using treated wood. The most common buck is built slightly larger than the actual door or window to allow for leveling and adjustments.

This type of bucking system holds securely to the wall when concrete is vibrated into the dovetail grooves. This system also prevents air and water infiltration.

idt_treated_wood_buck_2idt_treated_wood_buck_1

icf_midland_jail_2Custom metal frames are available to be set and poured into the concrete prepped and ready for door and glazing installations.


Concrete Placement

pump_truckConcrete is poured into the forms using a pump truck.

icf_concrete_consolidationConcrete vibrators are a must to consolidate concrete properly and eliminate voids.


Structural Integration

icf_vidor_1ICF walls are load-bearing, supporting beams and eliminate the need for steel columns. In some cases the amount of columns, light gauge metal framing and insulation that is replaced by an ICF wall is enough to pay for the wall.

icf_bar_joists_integrationBar joist with metal decking is the most common commercial floor and roof system and easily integrates with ICF walls.

icf_hig_poolThe Angelo State University project used hollow core planks on eight floors. Each floor averaged 11,000 SF with a three to four day installation schedule.

holiday_inn_galleriaWood and concrete are easily integrated.


Multi-Story Applications

leed_platinum_projectIn comparison to structural steel, ICF is very competitive in mid to high rise structures.

West Village Suites located in Hamilton, Ontario received LEED® Canada’s highest honor by attaining a Platinum Rating. The Student Housing Complex used a variety of green building products to meet its extraordinary goal, including NUDURA Insulated Concrete Forms.