Insulating a suspended floor: Caulk the seams or not, and is cellulose okay?
A friend of mine is building a tiny house on a trailer in Austin, TX (Climate Zone 2A), and has questions about insulating the floor.
First, should the seams of the floor framing be sealed with acoustical sealant before installing the insulation, to prevent air infiltration and increase insulation performance, or is some air movement good to prevent moisture accumulation and mold?
Second, is loose-fill cellulose filled from above an acceptable insulation material? I’m concerned because my understanding is that the insulation must contact the bottom of the subfloor, and that might be hard to do with loose-fill. We could slightly over-fill and then the plywood subfloor panels could compress the loose-fill, but then I’d worry about settling. She could always go with rigid foamboard, but she prefers cellulose if possible because the material is greener and it’s a little cheaper.
Finally, if you approve of cellulose, is it acceptable to fluff it up in 5-gallon buckets with an beater paddle on a drill (in my test that about doubled the volume), or is it necessary to rent the blower machine?
Thank you very much for your help.
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