On Tuesday, 13 April 2021 at 12:17:14 UTC+1, Bert Coules wrote:
Just over three years ago I had a major loft conversion done on my
semi-detached sixties bungalow: the process included removing and replacing
all the existing ground floor ceilings and building above them with a timber
carcass and new roof.

As expected, everything took a while to settle and establish itself and
there was some evidence of a small amount of movement, most noticeable in
the fit of a couple of sliding doors. But before long everything was fine.

Then in the last few weeks, the new ceilings/loft area floors suddenly
became startlingly noisy, emitting what I can best describe as intermittent
sharp (and loud) cracks. Since this mostly happens towards evening I'm
inclined to put it down to expansion and contraction, though there are also
isolated incidents of it during the day.

Am I right? And if so, why is it happening now? And should I be concerned?

Many thanks.
That does not sound good, do you live in a former mining area or is the area prone to sink holes. Some creaking is not usually an issue but loud cracks suggest further investigation is needed?

Richard