On 13/04/2021 11:17, 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.

.....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?

We've had a very long dry spell, with occasional very dry winds. I
suspect that the timbers are drying out to a level they haven't seen
before and shrinking in the process, leading to some unusual noises. Try
drying your laundry indoors...

--
Spike