White substance on attic rafters

[James E. Braun, CMI]

Thats not mold because mold growths will not have a sharp line edge. Also if the type of mold is considered toxic in the livingspace, it will be considered toxic in the attic. I have found, when tested that most molds in attic are not considered toxic. Most of your roof leals will test considered toxic though.

[Darin Redding]

Thread revival but it seems appropriate. Attached are some photos of a white substance that I found recently on home inspection. The substance appeared primarily on the wall where the fan is located, however it appeared in a few other locations as well. It is a white, soft, chalky material that looks a lot like drywall dust.

Any ideas? Could it be some type of chemical for pest control?

[James E. Braun, CMI]

Somebody killed the Pillsbury Doughboy in the attic?

No, that is not it. Sorry, I really have no idea

[Joseph W. Keresztury]

From the pattern
it's obviously a spray of some sort.
Very possibly for pest control as you mentioned.

[ROBERT V. YOUNG]

Same whitish staining.
Suspect: Plaster of Paris for damaged drywall repair in the commode.
Look at the Attic view of the venting can and hose.
They must have had an air handler moving the air out the gable venting.
Pour repairs everywhere.
Owner stated it was his nephew.

Pics in thread.
I agree with construction lumber.
Somewhat common in attics.
Seen lots of foundation by 6 or 8" s for flat decking or slope to the drain on pre 60's homes in my area..

[ROBERT V. YOUNG]

Originally Posted by sfogarty

Was there any white stuff on the exterior of the roof? Sniff it and see what happens.

I think you are thinking of the lick test Mr. Fogarty.
Also works for electrical conductivity testing.

[Kenton H. Shepard, CMI]

Originally Posted by jbraun

Somebody killed the Pillsbury Doughboy in the attic?

[Pete Campbell]

looks like stains from other materials found on a job site. The 2x6s may have even been slab edge forms in their previous life.