ASHRAE 160 standard and fiberglass insulation

[Michael Hurd]

The ASHRAE 160 standard sets criteria for potential mold growth and degradation of materials. Would it be safe to say that a fiberglass insulation that exceeds this standard's criteria would not be a concern since this material should not grow mold or degrade just because the RH within the material is elevated? I'm looking at a situation with Architectural Precast with fiberglass batts pinned to the precast. The WUFI results indicate elevated RH at the interface of the insulation to the precast, but the RH is probably not so high as to indicate a potential condensation situation. The insulation does not gain water over time, it cycles up and down like a well performing wall would.

[Manfred Kehrer]

Hello Michael,
I am at ASHRAE meeting in Las Vegas right now and we had the SSPC 160 committee yesterday.

I think it is not safe to say that. The Criteria says the MGI shall stay below 3.0.

The fact that there is almost no mold growth on fiber glass is taken care of by the individual sensitivity classes and please be reminded that there is always dust and other stuff contamination to grow mold on mineral materials.

[Michael Hurd]

Forgive my ignorance, what is MGI? Mold Growth index? If this is correct how are those numbers derived?

[Manfred Kehrer]

Yes MGI is the Mold Growth Index according to the Viitanen model and SSPC 160 adopted this model in 2016 for their evaluation criteria.
SPC 160 , 2016 version shows how the MGI is derived, a little complicated, but an experienced programmer can do that within 2 days.
Part of my companies core services is do that for WUFI customers though.

[Michael Hurd]

I'd like to say thanks, but I think you just told me my life has become more difficult.

Thanks anyway!

[Manfred Kehrer]

Lol......I don't think so
I am not that expensive for these evaluations as I already have already programmed a neat WUFI postprocessor for this about 2 years ago.

Contact me on WUFI.us if you want to have a proposal.