ICF's vs. Thermomass

A closer look at modern foundation systems:

Planning a home's construction comes with a multitude of considerations.  Choosing a foundation insulation system is one of the most important first decisions to be made.

There are a number of foundation insulation options, but no matter what, your end goals remain the same: sound foundation construction with thermal benefits that keep the home dry and comfortable.  In cold northern climates, this is particularly critical due to extreme annual temperature fluctuations.

As you select a foundation insulation system, remember that below ground, heat moves out since the indoor temperature is always warmer than the soil temperature, even during the summer.  Vapor and moisture move in the opposite direction below grade, transferring inwardly.  Proper insulation and moisture barriers will eliminate any concerns.

Two modern foundation insulation systems are changing the way builders and architects are approaching the process.  Let's take a closer look at Insulated Concrete Form and Thermomass.

Insulated Concrete Forms (ICF)

ICF's resemble foam Lego blocks that make assembly simple for either professional or savy do-it-yourselfers.  The light blocks feature an internal molded web which locks rebar in place, so no steel tying is required.  Molded lines on the form indicate proper location for construction processes, and cutting can be easily done with a hand saw - no special tools are required for this system.

Once the foam blocks are assembled, installers pour concrete between the forms, providing a secure, insulated foundation wall.  When the process is complete, the builder needs to cover external surfaces with appropriate materials to protect the foam form from UV and other potential damage.  On the inside, it's necessary to install a fire retardant material like drywall.  Ultimately ICF's can save time and provide excellent thermal ratings and soundproofing. 


This sandwich-wall system features rigid insulation centered within the foundation walls rather than on the outside.  Fiberglass rods keep the foam insulation in place and centered within the wall panels. The concrete is then poured on either side of the foam insulation.  Because this system is more complex, it's more suitable for the profession builders rather than the DIY homeowner.

Using the Thermomass system provides a long-term high R-value.  When the project is complete, the insulation is not exposed, unlike ICF's.  Buidlers simply have to waterproof the outside, there are no additional steps.  This system steamlines the process and eliminates the need for drywall in an unfinished space.

These are two systems that Braden Construction uses when building homes and commercial properties.  Give us a call to discuss what options are best for your project.