Hi everybody. I have a brother in law who is building a geodesic dome over a basement that was built using ICF's. I noticed that he was using 2 x 10 sill plates that came out flush with the outer edge of the icf's. This means that the inside edge of the 2 x 10 sill is flush with the inside face of his basement wall, but that the outer edge of the sill was extending over the actual concrete wall by about 1 1/2". My concern was that if he were going to set his rim joist flush with that outer edge that it would actually be setting over the ICF. Has anybody ever seen this done? There are sufficienct anchors on the sill that are embedded into the wall.
He chose the thickness of the forms that gave an acceptable r value. The sill width is a 2 x 10 because the wall is 9" thick, the forms 2.5", and because he wants to put on some type of decorative exterior. What he is doing I have found in the form manufacturer's manual as an optional sill plate configuration. Basically it is a cantilevered sill.