Insulating Concrete Forms as a Control Layer
Control layers of the building envelope include any air barrier and vapor retarder that are used to control the movement of air in and out of a structure and that controls the amount of moisture entering and exiting the home or building. Insulating concrete forms are great as two types of control layers.
As highlighted in the 5-in-1 ICF wall system page the EPS foam has a PERM rating of under 1.0, meaning it is categorized as a “retarder”. By using insulating concrete forms (ICF) as the building envelope no weather resistive barrier or “housewrap” is needed to protect the walls.
EPS Foam with a monolithic wall of concrete is virtually the most airtight wall as you can make. The product has been tested to achieve measurements of only 0.03-0.09 air changes an hour. By creating an airtight environment, the control of the interior environment is given back to the occupants of the building.
Impact of Effective Air and Moisture Barriers
A study that sampled the impact of an effective air barrier system in multiple types and sizes of buildings showed the following:
- A reduction in air leakage by 83%
- Gas savings of 40%
- Electrical savings of 25%
Air permeability can lead to other moisture concerns within the building as well. Building science models show that air permeability has the greatest affect on structural integrity due to damage caused by moisture content. Also, as an added bonus, by insulating concrete forms being an effective air barrier they also serve as an inhibitor of the spread of fire.