Attic Inspection Questions

Hi Everyone!
I’m studying the “How to inspect attics…” course and writing an essay on my own attic. I have two questions. Is the white stuff on the rafters white mold? It almost looks like it’s painted on. Very thin layer of powder that’s not easily rubbed off with glove. If it is mold, I’m assuming I need to have it remediated. Second question. The other picture is of the end of my house where an outside porch with a ceiling connects to the main. It’s open to the rest of the house and is not insulated. So it’s kind of like a giant soffit. Is this correct? Thank you!

Hey Daniel,

I believe the white stuff you’re seeing is from the board being used as a form board (for concrete) and then reused as a rafter. So my guess is no, the white stuff is not mold.

The dark grey/black spots on the plywood however does appear to be mold.

The only way to know for certain is lab testing.

Good luck man.

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Hard to tell from a picture, it could be some crystalline deposit or other form, but what it is not is concrete residue. I scraped too much concrete on lumber as a kid so it could be reused to know what concrete residue looks like. Only way to know for sure is to have it tested.
Here is a picture of concrete residue to compare.


Attic Observation:
Stained roof sheathing and rafters.
White powdery substance on rafters. Smudges when wiped with glove.Suspect: White mold.
Fastener corrosion.
Poor attic circulation.


Patrick, would that residue be kinda uniform?

I agree with @mcyr. If it was concrete residue it would be grey not white on the rafters as in the picture he provided. The black however is indicative of moisture and wood rot. In your first picture a rotted nail hole is pretty evident. The white appeared to have “washed” off somewhat closer to the sheathing. I would say it was some sort of primer/white wash or mineral based product that was applied once upon a time IMO. That could explain why it is hard to remove with just your hand.

As far as the porch area, if it is not in direct contact with the living space (over the living room for example) and not insulated it should have plenty of ventilation to allow for airflow through the attic opening shown in your 2nd picture. So depending on the overall construction and ventilation, one could think of it as a “giant soffit” as you put it. Better pictures would be needed though of that area… I have a very large covered front porch that is open to the attic (over the garage) but it is insulated on the ceiling and along 2nd story walls, and has 8 soffit vents for ventilation…

Thank you! I appreciate the input!

Great info! I really appreciate your time.

Thank you, Patrick. I really appreciate it!

Thank you Kenton! I enjoy your videos! I’m getting a lot out of them!

I was wondering the same thing as you and @mcyr said. I thought it was too white to be concrete (I know it’s hard for everyone to tell from the pic). In one of the pics, it looks almost like it had run over the edges like a liquid. I really appreciate your help.

I hate looking around my own house always find something thats been wrong for the last 80 years

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The white power could be chemical residue from botched mold remediation?

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I’ve seen this before also with dead mold or remediation the dead mold has to be scrubbed off.
Search on older posts on forums here.

What sticks out in the picture is the hacked rafters sitting with little bearing or blocking or anything to prevent rotation.

What prevents rotation?

You must not understand what rotation means or you would put a 3 inch pipe through the top plate. I don’t think that is a 3 inch pipe but if that is a 2x4 wall I think it would equal roughly 3 inches. What the rafters are sitting on looks to be the same thickness as the joists and rafters. The OP would know better but it looks like they are sitting on a joist.

You must be reading too many books, you definitely don’t know what you are talking about.

Nope don’t know anything I’m just trolling. Picture is deceiving because if that’s a 2x4 wall it doesn’t look like it at the angle taken. So I may have jumped on saying little bearing.
Now I am really curious what the rafters are sitting on. Because it doesn’t look like a wall.

Happy inspecting

NOOOOOOOOOO :upside_down_face: