"iamaran" wrote in message
. 1.4...
After some cajoling, the company sent a plumber over. He found that this
was indeed the case, and that all the water from the kitchen sink has been
going straight down. We have no basement or cellar.

Where on earth has the water been going, so that you weren't aware of it?
What sort of floor do you have in the kitchen, do you have floorboards with
an air gap beneath? Has the water been pooling under there, and/or soaking
timbers or something?

David