Shallow Insulated Footer
International Residential Code
Notes: in the picture above, 6" should be found between grade and bottom of wall to prevent splashing. This means that the footer would need to be a minimum of 12" or gravel layer should be lower unless there is another specific way to address water infiltration.
Floyd H. has been involved in CEB construction for the last 15 years. For foundations - he uses a shallow insulated footer. According to Floyd, this is sufficient to prevent frost heave - without using foundations that go below the frost line. This works only for heated structures. The theory is that the insulation allows the soil below the building walls to stay above freezing. Floyd has been using this in Missouri, where temperatures may go down to a minimum of -20F for about 1 week during the coldest winter time. This area of Missouri is in Zone 4, continental climate of the USA.
- Shallow insulated footer technique. Works for heated structures to prevent frost heave.
- Inside - poly goes under footer
- Outside - poly goes up footer and under insulation