Strange substance on floor structure

Can anyone give me an idea of what they think the susbstance might be on these floor joists? It seems to be somewhat crystalized. The joist on the left is cut and sistered so it makes me wonder if whatever it is, was or is causing a problem. Both joists seems completely sound. Some of the substance is also on the foundation wall. Any thoughts?

floor joists.jpg

Dirt? I don’t see anything unusual.

Let me give you a closer look at some of what i was looking at. It is clearly not dirt.




It appears that the subfloor was also replaced at one time. Can you tell us what was above this area?

The bathroom is above it. There is some moisture staining near the drain of the tub, but nothing too significant. But this doesn’t look anything like normal moisture stains.

That’s definitely moisture stains, but it looks like they tried to stain it afterwards, with all that splattering of brown liquid.

Did you probe this with your moisture meter?

The stain does not bother me nearly as much as the piss poor job of sistering or scabbing. There is not an adequate amount of overlap on that joint nor any form of support underneath it. Often we find crystallized sap from large knots in the lumber, especially in hot attics but occasionally in crawl spaces as well. From the photos it looks like some kind of stain material that slopped off onto the wood. Some of the stains look like plain old water stains that result from on an ongoing leak (very common under bathrooms and kitchens).

OOOH! maybe it’s BLOOD.

The brownish color reminds me of this:

Thanks. Have you seen that stuff applied? Does it leave a bit of a crystallized look once it’s on? It would make sense with the location and the fact that they cut the one joist.
And yes Doug, it is a piss poor sistering job. I knew that was bad, but what would be the proper way to do that if let’s say the last 24" of a joist needed to be removed?

Replace with a joist that spans the entire original length.
I’ve never run into an engineer that allowed scab/sistering on floor joists of the type depicted.

Definitely an unacceptable joining method, but back the question in the post. If the wood is sound and the moisture level was not elevated, I would not worry about the stains nor would I try to determine what caused them.

How about purple primer for cpvc or pvc. Bathroom remodel above?

I had the same thought. Did the bathtub have a garbage disposol attached to the drain?

Something wrong with the picture I am seeing on my end here.

The first picture posted, you see stains on the joist, and boards on the floor joist at a 45 degree angle and boards that are perpendicular to the joist closer to the wall.

Is it possible that some of those boards were changed in the past to create whatever and stained for appearance and dripped down in the basement onto the foundation wall and some of the joist. ?

Just a thought.

Oh, the sistered joist is only a half sister and not part of the family approved by the elders. ha. ha.

Marcel :slight_smile:

Yeah…they had rotted joists,then tried to stain after which they cut out the rot.
Crappy…(double meaning intended).