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 effervescence 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.
Photos at
Any ideas?
Thanks.