How water gets into a house here
Ask what causes water damage in most of the country and the honest answer involves weather. Ask it here and, for most of the year, it does not. What follows are the six mechanisms that actually account for the calls across these cities — and the thing they have in common is that none of them announce themselves.
Why the list looks like this
Two regional facts shape all six. The first is that it does not rain from spring to late autumn, so nothing prompts anyone to check — a leak that would produce a damp corner and a phone call in April somewhere else runs quietly here until something structural moves. The second is that the housing has no basement, so the room where water would normally show up first, and where people keep things they look at, does not exist.
What replaces it depends on which of these cities you are in. Under the older houses through north Inglewood, Magnolia Park and Uptown Whittier there is a crawl space, which is the one place on this list that can actually be inspected — and almost never is. In the post-war tracts of Cerritos, Downey and Simi Valley there is a slab and an attached garage. In the stacked housing of Long Beach, Glendale, Hawthorne and Redondo there is a unit above, and the water arrives through a ceiling belonging to somebody else.
The six
What happens next
Whichever of the six it turns out to be, the sequence afterwards is the same: stop the source, measure how far the water went, dry the assembly to a reference reading, and only then put the building back. Water damage restoration across the Los Angeles basin covers what each stage involves. Where the water has been in place long enough to have consequences, mold inspection is the other half of the same job.