Insulating Concrete Forms (ICFs) in Tropical Climates

Whereas many people in developing countries can see the benefits of using insulating concrete forms (ICFs) in new construction, the issue comes to the effectiveness of ICFs in tropical climates. Ghana is a tropical country with temperatures ranging from about 21 degrees Celsius to 32 degrees Celsius (70 to 90 degrees Fahrenheit) and high humidity. There is little difference between the day and night temperatures. ICFs, proven to perform well in seasonal climates, also perform well in tropical climates.

Insulating concrete forms (ICFs) are a stay in place foam block that stacks to form foundation and structural walls. Once rebar is placed, concrete is poured into the cavity creating a 10.16 cm (4 inch) solid concrete wall with 6.35 cm (2.5 inches) of insulation on each side. This creates a building that is sturdy and energy efficient (R-value 22).

The 10.16 cm (4 inch) solid concrete wall forms a thermal mass for the home. It takes a long time for thermal mass to heat up. Concrete makes a good thermal mass material because it is a slow conductor of heat. If shaded from the sun, the concrete in the walls effectively prevent the heat of the climate from entering the interior space of the building. The shade is produce by the 6.35 cm (2.5 inches) of insulation on each side of the concrete wall. Once the home or building is constructed, the ICF block stays in place allowing the expanded polystyrene (EPS) panels to serve as building insulation.

Ghanaian builders normally build homes out of concrete blocks with no insulation. ICF concrete homes would be surrounded in expanded polystyrene (EPS) insulation. EPS is used in cold storage facilities, mobile refrigerated containers, and commercial grade coolers. Foods placed inside of coolers stay cool for extended periods of time, especially with the addition of an ice pack. Like the items in the cooler, people in ICF homes and buildings would remain relatively cooler than in conventional built homes and buildings.

Some Ghanaian builders resort to simply applying EPS panels to the walls of concrete block buildings. Whereas this construction method does produce a better building than concrete block alone, it still uses the same labor intensive method of concrete block construction and reduces the benefits of having a solid concrete wall.

ICFs are much lighter than concrete blocks, weighing only 6.5 pounds per ICF block. Because of the weight, it requires less muscle endurance or strength to become valuable laborers. A crew used to building with concrete blocks can make the transition easily to ICF blocks. Each ICF block covers 0.495 square meters (5.33 sq ft) of exterior wall space. Homes are built in half the time as with concrete blocks and a building is produced that is structurally sound.

Owners of ICF homes experience cooler, even temperatures in tropical climate areas. If the home owner chooses to install a cooling system, the home owner will experience a reduction in the need to operate it. Because of the resistance to heat transfer found in ICF block construction, ICFs are beneficial in all Ghanaian new construction.

Lakisha David
Light Ready Construction, LLC
www.lightreadyghana.com