Robert11 wrote:
Hello,

Just curious-

Water leaking on plaster wallboard always seem to stain a brownish color.

Doubt that the brown is from anything in the water directly, but perhaps ?

More likely it's some chemical reaction.

Anyone know what actually causes the brown color ?
....

Precisely what, no I don't. But, a piece of white typing paper tends to
discolor in similar fashion. I think it's more than likely salts
dissolved by the water, perhaps w/ some iron, but as noted exactly
who/what I'm not certain (and not inclined to really go digging altho I
suspect one could come up w/ some reasonable candidates w/ a little
digging).

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