After quite a lot of research I have decided I am going with Roxul Comfortbatt residential stone wool insulation for my go to insulation. While I don’t think you can say one single type of insulation is the best for all application I feel Roxul is good for the core of an insulation system. Any place you would use fiber glass I feel Roxul stone wool is a better choose. You can get Roxul in batts of 3.5 inch (2×4) R15, 5.5 inch (2×6) R23 and 7.5 inch (2×8) R30 with all size in both 16 and 24 inches. So why Roxul vs fiber glass.
- It matches or exceed fiber glass R value for the same thickness.
- It performs better in a fire than fiberglass insulation.
- It is denser so is has less airflow than fiberglass.
- It is water resistant
- has low moisture sorption.
- Better sound absorption.
- Easy to cut to get around wires, electrical boxes, pipes, etc. and shape for optimal fit.
Another point I would like to make is that whether you go with Roxul or fiberglass use batts not loose fill/blown in. Loose file loose R-Value as the temperature drops where as batt tend to actually gain R-value. This is do to higher air flow in loose fill and blown fiber glass special convective looping than in batts.
I will be writing a more detailed review later but I just want people to know about the Roxul option.