Crawl space stuff???

Anybody know what this is? I’ve seen it many times but do not know what it is. It’s a hard white crystal substance on the bottom & sides up about 3" on the floor joist.




It almost looks like it flooded that high----is that a possibility? I had one a while back with seaweed hanging down from the insulation.

This house has 5 different crawl spaces, 3 is all I could find access to. The 2 others had vapor barrier in this one did not. And this is the only 1 found with this on. Botttoms of joist are 8-10" above ground, impossible to flood that high at this location. Should have taken samples and sent to ProLab just so I would know what it is.

With the line being that level, I would imagine it was a flood line.

Whatever it is, it doesn’t appear to be a defect in the wood members.

I don’t think it is a defect either. There were no holes (insect infestation) or rot on the joist. Just the hard white crystal like deposits on the bottom & sides.

The 3rd picture is where I wiped the side off to check for any holes & rot.

What was the venitlation like?

Ventilation was minimal. 4 vents for the original 1800 sq. ft. house. But as I said this 1 of 3 sections of crawl I could get to is the only one that had it.

How old is the Home?

Is it possible that it filled up during construction? Or major plumbing leak? Sure looks like a flood line.

Saw this once before on a repo home. Had an electric sump pump in the crawl space; however, the bank being the intelligent people that they are, decided to save some money by shutting off the electricity. This was able to let the crawl space continue to fill up with spring time ground water. But they were able to save the monthly electric bill. :):):slight_smile:

Looks like mold to me (though I never use that word)!

It looks like the result of air stratification in the CS. The line of delineation is where the warmer air is stuck up between the floor joists. The warmer air is probably not conducive to this type of mold.

House is a 1959. I looked under 3/4 of the house, could not find last access, this was in only 1 of the sections I looked in. It was also the only 1 w/o vapor barrier. Possitive there was no way to flood this high as all the sections were interconnected by way of water would be able to go over the dividing walls, the water would have been level in all crawls. O/S grnd level is 8" below the joist and in flat country, Whole county would of had to go under water. Next time I see this I’m going to get a sample off to ProLab.

Maybe someone removed the floor insulation. The “mold” was under the insulated line.

No other signs of old insulation.

I was wondering if the crystals were hard. Sometimes the sap from the lumber comes to the surface over time.

Yes the crystals were hard. But this cut off line of were it starts & ends was on most of the joist in this section.

It appears that the wood is Douglas fir judging by the coiour. If I am correct then it is the pitch crystals that have solidified at the surface. This does not reduce the strength of the wood.
The line on the wood itself indicates the difference between the live (new) wood and the inner core of dead (heart) wood. We see that condition all the time here on the west coast of B.C.

Hello Mr. Figert:

We scientists have a technical term for that stuff on the wood - we call it “money.” People call me up, and ask: “Can you come out and tell me what this is?” and I answer: “How much (money) do you have?” When they say, I have lots of it (money), then I tell ‘em I will be there in half an hour and I will take care of it (the money) for them.

I love that stuff, it makes my accountant and mortgage company happy – and when they’re happy, I’m happy. :smiley:

Caoimhín P. Connell

(The post expressed here is a joke and does not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for fun only and does not reflect professional advice and is not intended to supercede the professional advice of others.)


Still seams odd that it was only it this 1 section of crawl. Did not suggest to the client that it maybe a defect in the strength just that I’ve seen it before but did not know what it is. Thanks Terry but I think it was SYP, as that is what is used most in this area, but it could have been. I did not even think to determine what type of wood it was. Thank for all the help guys.