Mineral stone wool insulation batts are slightly better insulators ... while a standard fiberglass batt made to fit in a 2×4 wall has an R-value of 11 or 13. However, you can special-order ...

Scherger recommends trying BATT insulation (pre-cut rectangular insulation often made from mineral or glass wool), adding, 'iFOAM Fiberglass BATT insulation is an affordable option that provides ...