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Old 10-30-2008, 01:27 PM
1 posts, read 10,372 times
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[FONT=Arial]Your help would be appreciated.[/FONT]
[FONT=Arial] [/FONT]
[FONT=Arial]Under the house in the crawlspace are white streaks that seem to have a pattern. The photos are from in the crawlspace looking up towards the floor joists. Above the joists is the subfloor, then hardwood flooring on the top. The while areas are under a bedroom and in the living room. There are no water sources in these rooms.

It does not look like the streaks have changed in almost two years, yet the bedroom does have a damp smell to it.

It looks like the streaks come down from the area in between the subfloor panels and cascade down the side of the joists. Also, in the picture, you can see the white streaks running in the gap between the subfloor panels.

A home inspector said it looks like [FONT=Arial]effervescence[/FONT] where there was moisture at one time and it left the minerals behind when the moisture evaporated. That may be, yet the white streak areas cover a 10x10 bedroom and about 5x10 of a living room. The pattern of white areas does not look like the random cloud formations of mold (where mold seems to grow out in all directions). Also, the white streak areas are not fuzzy. It feels like a dry hard powder.

This is from a typically warm climate in California.

Any ideas?

Attached Thumbnails
Mold, mineral deposits, or what???-dscf2762.jpg   Mold, mineral deposits, or what???-dscf2759.jpg  
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Old 10-30-2008, 01:59 PM
Location: Visitation between Wal-Mart & Home Depot
8,309 posts, read 33,322,966 times
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It looks like there are actually spatter marks in the first picture so I think that this is the result of a lot of fluid at once rather than a gradual exposure. I suppose that could be mold, but I think I agree with the inspector about deposits left after evaporation of some fluid.

Is there a bathroom adjoining/adjacent to either of the rooms with these marks? It could be that there was a major water leak at some point in the history (or construction) of the house. A big spill can run underneath hardwood floors, I saw a house in Houston that had an inch of water under about 200 square feet of hardwood floors from a (badly) leaking shower pan.

Maybe soap deposits from a cleaning prior to the installation of the hardwoods?

Are these marks on the joists uniform throughout the affected area of the crawlspace or are they larger/more severe in certain areas?

Last edited by jimboburnsy; 10-30-2008 at 02:08 PM..
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Old 10-30-2008, 02:05 PM
Location: Montrose, CA
3,031 posts, read 7,862,833 times
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Huh. Looks like something leaked down between the joints of the floor and stained the beams. Like someone got really enthusiastic when mopping the floor, and poured buckets of soapy water onto it.
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Old 10-31-2008, 07:55 AM
27,903 posts, read 33,414,651 times
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Looks like residue from gypsum floor boarding that got wet. Do you have proper ventilation in the summer in the crawl space? If (and a big if at that) it's a very high humidity level in the crawl space and you keep your home rather cool there is a slight chance you are getting condensation forming on the underside of the floor. (That's a big if as it would have to be pretty wet underneath the house. In the winter time it should not happen as the outside air is much more dry.

Edit: Never mind I see the splatter marks now. It would have had to been a flood of some type for that to have happened.
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Old 10-31-2008, 11:13 AM
Location: Grosse Ile Michigan
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Ectoplasm. You house is haunted and ghosts are squeezing up throguht the floorbards and leaving some ectoplasm behind when they brush against the floor joists.

That might also be the residue from radioactive waste buried under your house.

It is very unlikely that it is mold. Looks nothing like mold.
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Old 10-31-2008, 08:32 PM
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Looks like dust from the concrete and other things and that they have gotten wet and dripped some from moisture.
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Old 11-01-2008, 04:24 AM
Location: Grosse Ile Michigan
24,717 posts, read 59,563,864 times
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It is clearly something that leeaked through the flooboards from above. Loot at the location pattern and shape of each stain. It starts at each joint in the subfloor and widens out. Something leaked through.

Do you have hardwood floors? Could be wax

Carpet? Could be soap from steam cleaners
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Old 11-01-2008, 09:22 AM
Location: South Dakota
733 posts, read 4,079,599 times
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When your house was sheetrocked or plastered, as the case may be, materials were mixed, tools were cleaned, etc. and water and gypsum/plaster/etc. got sloshed all over. That was done while the subfloor was in place but before the underlayment and finish floor were installed. The subfloor got swept up, underlayment placed, and the site of the "sloshing" was covered up forever - except when you see from below where it leaked through.
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