Concern of possible subsidence?

[pbooks]

I am concerned & require advice concerning problems that I have noticed in my house that have got worse over time, which may be possible subsidence problems.
The first problem I noticed was that the tiles built covering pipes in the bathroom had split from there square shape at the part where the tile is sealed(grouted).
Secondly I noticed that there was a slight movement of the squirting board (at top of squirting from wall & squirting) of approx 3 to 5 mm running down my staircase on each side.

I have felt that there seems to be a tremor each time a plane goes over. I do not live under the flight path but near it & have lived in this property for 13 years, but have noticed this slight tremor get worse/noticeable over the last 12 months.
I`d appreciate any comments. :?: