Suspected mold from cellulose insulation

[Ernie Simpson]

Had not one but two inspections in last couple of weeks where the attics were blown off with cellulose. In one attic in particular, the cellulose was blown onto the roof sheathing and rafters. When you look at the pictures, it appears that the cellulose (which after all, is organic) is causing mold accumulations.
Who else has seen this? Should this home have a mold remediation? I did say I thought this would be necessary on one home; on the other home the degree of the insulation overshoot and suspected mold was so slight I noted it but did not think it rose to the level of a mold remediation, but am I being insufficiently cautious?

[Ernie Simpson]

Note: these photos were all from the 'bad' home. No photos from the other home.

[Billy Stephens]

Had not one but two inspections in last couple of weeks where the attics were blown off with cellulose. In one attic in particular, the cellulose was blown onto the roof sheathing and rafters. When you look at the pictures, it appears that the cellulose (which after all, is organic) is causing mold accumulations.
Who else has seen this? Should this home have a mold remediation? I did say I thought this would be necessary on one home; on the other home the degree of the insulation overshoot and suspected mold was so slight I noted it but did not think it rose to the level of a mold remediation, but am I being insufficiently cautious?
.
Ernie,

Blown in Cellulose contains boric acid , I think this is what your seeing as" mold accumulations " and not an active mold growth. see attached http://www.nationalfiber.com/docs/SprayAppliedCelluloseInsulationandMoistureFacts090 9.pdf for further insight about moisture or lack of in Blown in Cellulose. No Moisture = No Active Mold Growth.
.

[Benjamin Thompson]

Unless you are a mold expert and / or certified, I would be hesitant to call for remediation. I think I would say something like evaluation by a mold expert with remediation if needed. Like Billy said, cellulose has mold inhibitors. Doesn't mean there isn't a moisture / mold issue but it probably doesn't have anything to do with the cellulose.

[Raymond Wand]

Looks like sap staining/ooze.

In my opinion if there is mould it would be on the decking, also the nails don't appear to be rusting.

[Scott Patterson]

Had not one but two inspections in last couple of weeks where the attics were blown off with cellulose. In one attic in particular, the cellulose was blown onto the roof sheathing and rafters. When you look at the pictures, it appears that the cellulose (which after all, is organic) is causing mold accumulations.
Who else has seen this? Should this home have a mold remediation? I did say I thought this would be necessary on one home; on the other home the degree of the insulation overshoot and suspected mold was so slight I noted it but did not think it rose to the level of a mold remediation, but am I being insufficiently cautious?

To say the insulation is the cause, is a big statement that I would not make. I have seen mold growth like you are showing in many attics over the years and it is usually related to poor ventilation of the attic.

Based on the photos it looks like this is an older home. Older homes were never designed for our modern energy savings ideas and products.... It could be that the insulation has compounded the problem by sealing off the the attic even more, this I do not know for sure as it is based on the photos but it is very possible.

[Markus Keller]

Not seeing any mold like substance in any of those pics. The insulation doesn't look to be affecting anything. "Age typical" conditions.

[Mark Fisher]

I've never seen cellulose grow mold, even wet patches. Looks like a ventilation issue from what I see. And I agree with Scott that insulation retrofits change attic conditions which affects when and on what surface condensation occurs.

If that is indeed mold on the rafters, it is interesting that there is none on the roof deck.