We've lived in this house for about 6 months, it's in the Sunset District of San Francisco. The sunset if you don't know, was once sand dunes, all the way to the ocean.
The house was built in 1939, and looks to have the original cast iron drain pipes in the basement.
The house has a center patio. That is, a room in the middle of the house, which is outside. The patio drain / kitchen sink drain were clogged about a month ago. Plungers, et cetera didn't work (I didn't try a snake/auger, haven't bought one yet), but a shop vac in reverse (blow) did work (blew crap all over the ceiling from the kitchen sink drain which is adjacent to the patio). One thing I noticed when clearing out the drain in the patio, there was a bunch of what looked like beach sand backing out of the drain.
Now, our shower and bathtub are clogged. The shower drain was starting to slow down, I decided to plunge it last night, and that maneuver only made things worse. Now, both the shower and tub are completely clogged, and not draining, and again, I've got sand coming up from the drains. I've tried having my girlfriend hold one plunger in the tub while I plunge the shower and vise versa, but to no avail. I'm going to try my shop vac method tonight. If that doesn't work, a snake. Unless someone tells me using a shop vac for this is bad for some reason. It really surprised me when it worked.
I'm wondering if anyone has ever heard of beach sand getting in the drain pipes of a house. How could it get there? Is it backing up from the city sewer, or coming in from the vents? If from the vents, which are simply open at the top, is there anything I can do to stop the sand from blowing in? Could the sand be the cause of my drain problems?
Thanks very much, John