A. Paul Fisette, director of Building Materials and Wood Technology at the University of Massachusetts Amherst and a JLC contributing editor, responds: I would be concerned about the moisture trapped in the floor system and would take active steps to dry things out. When there are very low rates of air exchange, the primary drying mechanism is diffusion, which is pretty slow, particularly with relatively impermeable materials like OSB or plywood decking capping the floor system. Furthermore, not only is the wet fiberglass loading the joist bays with moisture, but so is the recently poured concrete slab — and it will continue to do so until the concrete fully cures.
Although the floor system will eventually dry out, there is considerable potential for mold and mildew growth in the meantime. Also, the OSB web material in the I-joists could swell irreversibly, possibly compromising the critical web-flange connections. Whether you go in through the top (through the OSB) or through the side (through the rim...
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