Rim Joist Rescheck Insulation Question

Rim Joist Rescheck Insulation Question

Today on the Reschexper blog we wanted to discuss a question and case study of Rim Joist Insulation on a Rescheck with interesting results. A Reschexpert blog reader chimed in with an instance of how they were being asked to insulate a rim joist. A case of a Rescheck and an insulated Rim Joist turned from a simple answer to an interesting Rescheck that should be shared with other on the Reschexpert blog.

This particular story begins on a home that was constructed according to the Rescheck that passed by well over 15%. The builder and the inspector were at odds over whether the rim joist was insulated correctly.

If you take a look at the first picture you can see R13 walls, an R19 subfloor, and R13 walls in the foundation. The gap between the R19 subfloor and the R13 walls is what the inspector wanted insulated.

If you look at the second picture. The red and blue arrows indicate where hot and cold air would infiltrate the main floor of the home. That one rim joist band around the perimeter of the home is effectively R-0 so the inspector says to insulate.

Here is where the interesting Rescheck dilemma ensues. I took that approximately 100 feet of R0 wall area and added as a line item into Rescheck. So basically, the Rescheck no included the 100 foot band of wall area without any insulation. To my surprise the project still passed by 10%.

What does this mean? Well the Rescheck passes, but that does not absolutely mean that the building inspector will accept it. When it comes down to fine details in local jurisdictions the building inspectors and officials have the final say as to what they will accept on the Rescheck. In this instance the deficiency could be fixed with only 100′ of R13. So you have a choice. Do you go to battle with the inspector of $200 dollars worth of insulation or do you install it in an area that would probably help the home be more efficient even if the Rescheck says it passes.

There is no right or wrong answer here and I see building inspectors requiring things that Rescheck does not suggest all the time. In the end your local inspector should be seen as a resource and in this instance he has found a significant area of the home with R-0 insulation. They would like to see it insulated. The Rescheck says it will pass either way.

If you need a Rescheck on an interesting New Construction, Addition, or Alteration simply email PDF plans, jobsite address, and square footage to service@rescheck.info and we will get you taken care of.