hi,

I built a house that is supported by helicoidal piers. I need to insulate the floor and would like to know what is best practice and what it is to avoid.

Some told me to insulate the cavity with fiberglass batt that touch the underside of the floor (higher position) and secure those batts in place and then close the system with sheating. I can probably put some fiberglass batt than XPS and then sheating.

Some told me to insulate the cavity with fiberglass batt and then place a vapor barrier to the outside and finish with sheating. I wonder of a vapour barrier on the cold side of the assembly? is this good?

What would best partice to insulate that assembly.

Best regards,

Pierre