Building My Net Zero Energy Home: Floor Joists

Reader Contribution by Staff
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In this photo, one of my workers, Joy Coyle, is helping install the band joist from which we will hang the floor joists.  Because the band joist an area where a lot of energy moves in and out of a home by infiltration and exfiltration as well as conduction, we attached it directly to the inner surface of the ICF foundation wall.

With the foundation walls poured my two workers and I installed the steel beam and floor joists. Joists were attached to the steel center beam by hangers (shown in the center of the photo). The other ends of the floor joists were attached to the band joist. We suspended the joists by hangers. This design eliminated all bridging loss through the band joist, and, thanks to this choice and other design features, all air movement as well. 

Once the floor joists were installed, we began to install the subflooring, in this case ¾-inch OSB. I sealed all the joints with silicon to create an airtight seal and also to prevent water movement from the concrete and earthen floors we poured later during the project. I sealed the floors where earthen floors were installed with water-soluble, no-VOC, polyurethane knowing that it would take these floors much longer to dry that it would take the concrete to set up. 


Contributing editorDan Chirasis a renewable energy and green homes expert who has spent a lifetime learning life’s lessons, which he shares in his popular blog,Dan Chiras on Loving Life. He’s the founder and director of The Evergreen Institute and president of Sustainable Systems Design. Contact him by visitinghis websiteor finding him on.