Category: TJI insulation cavity

We are thrilled at the success and completion of our first Foam-Free, (near) Net Zero, Passive House in Western Maryland.  The home is currently in the final stages of testing, certification and interior finishing. Most of the progress can be followed on their website, it’s nicely detailed and as such might offer good inspiration to those DIY types. It has been an educational process with material usage, system selection and install, air sealing and insulation, window install and team collaboration.

The views and placement of the house are extraordinary and achieve the homeowner’s goal of a comfortable, accessible, high performance home designed to view the meadow, marsh and forest.

For more photos of the final walk-thru, visit the project page.

Upon hanging the TJI insulation cavity, the vapor open Weather Resistant Barrier (WRB) was installed and all seams were taped.  Given the pressure of the cellulose that will be blown-in behind this WRB, we decided to use Solitex Mento 1000 and taped with our favorite Tescon Vana tape.

The next layer is the ventilation cavity / rainscreen / furring strips.  We decided on horizontal with vertical furring strips to keep the cellulose bulge in check and maintain an acceptable ventilation cavity as well as provide a more substantial nailing surface for our engineered wood siding.

We have built our structural 2×6 wall, installed and taped the plywood air barrier, and have created all of the window boxes.  It is now time to attach the 11 7/8″ vertical TJIs to our wall.  This TJI cavity will be filled with cellulose and serve as our main insulation layer in our Climate Zone 5 project location.  The TJIs are non-bearing and their vertical installation is addressed by Weyerhaeuser TrusJoist TB-821-2014 (comes up on a google search).

Per the advisement of our structural engineer, in the areas where the TJI is not resting on the concrete foundation wall (with a bit of mineral wool sandwiched between), but is instead ‘floating’ we used a light 40 series joist hanger at the base of each TJI.  He also called for blocking top, bottom and mid-height.