Thread: Large amount of white substance in crawl space

Hello,
I am looking to purchase a home in southern california. It was built over a crawspace in 1962. I had a great general inspector but he was too big to go to the far end of the crawlspace. So, I went back a second time to check back there. I was surprised to see about 200+ sqft of the ground covered with white stuff (see pictures). There really was a lot of it, but none (or not nearly as much) near the crawl space entrance on the other side of the house.

From googling, my best guess is that it's efflorescence rather than mold (it does crumble like salt). Is this guess correct? Either way, should I be concerned about this? For what it's worth, the wood in this area of the crawlspace seemed to be in pretty good shape--not rotten or anything like that.

Thanks for your help!

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Is that on dirt, not concrete? Did you rotate the camera for that shot?

Efflorescence indicates moisture is rising up from below or in from the sides. It usually can be controlled by installing a vapor barrier on the ground, or seal coating the outer wall of the foundation wall.

Thanks for the quick reply, John. Yes, it is on the dirt. I rotated the picture so that I could include more of it within the website's picture limitations. Sorry for the confusion.

So, this does indicate a pretty serious moisture problem that should be addressed? Do you have a ballpark idea on how much those remedies would cost?

Thanks again.

Originally Posted by Rob Radtke

Thanks for the quick reply, John. Yes, it is on the dirt. I rotated the picture so that I could include more of it within the website's picture limitations. Sorry for the confusion.

So, this does indicate a pretty serious moisture problem that should be addressed? Do you have a ballpark idea on how much those remedies would cost?

Thanks again.

Were your clothes muddy when you came out of the crawl space?

Hello James,
Thank you for your reply. My first reaction to your question was "no, my clothes weren't muddy, but they were very dirty" and it just didn't feel that wet to me down there. Upon thinking about it more, I'm not exactly sure where the line is between getting dirty and muddy.

I attached some pictures of the clothes/shoes I wore down there. They haven't been washed, but I did knock a fair amount of dirt off with my hands when I got out. My hands/arms were pretty dirty too and I had to wash them to get all the dirt (or mud) off.

What do you think? Would these clothes meet your definition of muddy? Does that indicate that there is too much moisture down there?

Thanks again for your help.

Rob

Nope, that's not muddy like I know muddy. Did you rotated those pics, too?

Sometimes there will be a moist area, like a low patch, in an otherwise relatively dry crawlspace. Just cover all the exposed earth with a polyethylene vapor barrier. That will take care of most of the concern right there, and is the most cost-effective thing you can do..
You can upgrade from there to sealing all the edges of the poly with tape or goop. Cheap, but strenuous exercise.
You can upgrade to heavy mil poly like pool liner material. That is for the wet holes, extreme cases.
You can upgrade from the thin poly by spreading a concrete slurry over the entire floor. That would make me the happiest. I love a concrete floor.

Originally Posted by John Kogel

Nope, that's not muddy like I know muddy. Did you rotated those pics, too?

Sometimes there will be a moist area, like a low patch, in an otherwise relatively dry crawlspace. Just cover all the exposed earth with a polyethylene vapor barrier. That will take care of most of the concern right there, and is the most cost-effective thing you can do..
You can upgrade from there to sealing all the edges of the poly with tape or goop. Cheap, but strenuous exercise.
You can upgrade to heavy mil poly like pool liner material. That is for the wet holes, extreme cases.
You can upgrade from the thin poly by spreading a concrete slurry over the entire floor. That would make me the happiest. I love a concrete floor.

I agree....that ain;t muddy!

James and John,
Thank you very much for helping me get a handle on all of this. I'm glad to hear that the problem isn't extremely severe and that the remedy is fairly straightforward.

Sincerely,
Rob