I have a 70 yr old farm house located in South Coastal British Columbia. The house is cold and leaky but is in reasonably good shape for its age. I had air samples taken 2 years ago which came back showing a high mold spore count. I have not found any signs in the walls where I would suspect it to be so I have ripped up the floor in the master bedroom, thinking that it could be sandwiched in between the multiple layers of subflooring. This is giving me an opportunity to add insulation since most of the house is only 12-18 inches above grade, with some sections only 8″. My plan is to finish covering the bare ground with 6mm poly, then install 1/2″ OSB and 2 1/2″ of EPS in between the 2×8 joists using a cut and cobble approach. This would provide an extra vapour barrier between the cavity and the ground and give me approximately R-10. I would then fill the remainder of the cavity with blown-in fiberglass leaving a 1/2″air gap below the subfloor. This would give me R-20ish which seems excessive, however, I plan on renting the blown-in equipment so that I can insulate the laundry room walls at the same time so the cost to do the floor would be fairly negligible. Do you see any issues with this approach? Should I be concerned about trapping moisture in the cavities? Should I omit the blown in and just install the EPS? If so, should it be moved to the top of the cavity?