Random Floor Joist Damage?

In a basement yesterday there was like 3 random floor joists that had this rot/damage/decay? I never seen it in such a way that it resembles insect damage but yet it doesn’t resemble because I don’t see tunnels and in these areas it more like dry rot but I never seen it appear in this manner. What would cause a board to have this sort of spotting damage?

I didn’t know how to look up or describe this sort of damage so this is the first place I came.


Looks like cubicle brown rot. Results from moisture issues. Wood should be repalced if its soft or can be picked apart.
Some type of fungus eval should also be done. If other wood has the same fungus, the damage will continue.

Basement 1/2 finished (carpet and paneling). You can see spotting mold on the paneling and floor molding in places. There was a perimeter drain leading to a sump and the drain appeared recently serviced or cleaned and filled with gravel I assume to keep out debris and allow it to function. I believe this because the gravel was still bright white and clean looking. The block walls also appeared recently painted white where there was no paneling. The sump just replaced, old one sitting to the side and box for new there as well.

So I will google cubicle brown rot.


Old WDO damage and plain old wood rot often go hand-in-hand. Could be one, the other, or both. When I’m perplexed I say: “I observed old WDO damage and/or wood rot…”

Note my use of “and/or”

And I include a PIC.

Both weaken the structural integrity of wood, so I don’t think it horrible that I’m uncertain about the cause.

Brown rot. Because the surrounding wood looks sound, this problem may have started from an injury to the standing tree.

I don’t understand what kind of an answer you are looking for. This piece of wood has dry rot fungus, nothing more need be said.

All rot is caused by an organism of some sort.