Howdy,

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