The message
from Mark contains these words:

I know this is a difficult question to answer but can anyone tell me
how I find out if this is a serious problem and what can be done about
it. The house is a 1960's semi if that's any use.

Every house I've ever lived in has had pipes fitted like that.

Do you have any particular concerns that lead you to think there might
be a problem with it?

--
Skipweasel
Pay no attention to that man behind the curtain.