Weird foam coming from crack in garage floor

[andrewket]

This is lime salts leaching from underneath your slab. It is due to excess moisture underneath your slab, and/or improper moisture barrier applied underneath it. It has nothing to do with your car! In the summertime see if you can improve the drainage away from your house to keep the soil drier.

Perhaps the weight of the Tesla compounds the issue? Forces the moisture up?

 

[AMPd]

or put a bit of acid on it and see if it bubbles.

or not since aluminum oxide will react w/ both acid and base...bad test

 

[Chipper]

This is lime salts leaching from underneath your slab. It is due to excess moisture underneath your slab, and/or improper moisture barrier applied underneath it. It has nothing to do with your car! In the summertime see if you can improve the drainage away from your house to keep the soil drier.

Doesn't seem to be "weird foam dripping from the car" if that is the case.

 

[ZipByICE]

You can try to test it to see if it is aluminum oxide. Aluminon is used for this:Aluminon for Qualitative Analysis ACS Reagent 30g GN | eBay.
No, I am not the one selling this.

 

[huntjo]

Yeah that and stripper glitter keep building up in on the back seat of my P85.

Glad I'm not the only one!

 

[AoneOne]

Noticed this dried up foamy stuff under the car, like it dripped off and crystallized. Not salt (bay area).

Maybe residual car wash soap? I go to Foster City touchless, but it has been weeks since I last went. Or something else I picked up from the road?

View attachment 43091

Looking at the photo, the powder seems to divide the floor into lighter and darker areas. Wildly guessing, I'd agree with other posters that the car's weight and/or moisture dripping from it has cause an accumulation of efflorescence or something similar.

 

[Kipernicus]

Yes the thread was not accurately titled due to my cluelessness

It is possible that the cars weight is a factor, maybe even cracking the cement. I don't recall if it was cracked before getting the car or not, but the location is right under the wheel.

Right back wheel.

Under the car

PS - I put some lemon juice on it and it did not bubble.

 

[GDH]

What I see is moisture and a crack so my guess is that whomever said it might be under the floor right. I also googled it and found this:

Removing Floors

 

[Doug_G]

View attachment 43367

Well, there you have it. It's definitely coming out of the crack in the concrete.

 

[MikeL]

Whew, that's a relief! Yours is a very special Model S, Kip. . . the first Tesla I ever drove!

 

[tezco]

Yes, definitely efflorescence. Water is getting into the concrete, either from up top or from underneath. Since it appears localized to the crack, I suspect it's coming from above. An application of a water sealer might help.

 

[birdsaresmarter]

+1 to soil moisture. Coincidentally, today, FWIW, I saw this exact same "foam" collect when I was watering by slow soaks (due to having no rain this year). Specifically where the soil was heavier/granitic. If you don't think water is getting in from above surface, if there is persistent sub-surface water, I suppose it could be why the crack appeared in the first place. Being at the base of a slope, doing a lot of landscape watering or having a leaky pipe are all possibilities for moisture to persist where you did not first suspect.