Hi,
First time poster here.
Has anyone come across a loud banging noise that occurs mostly at night and is loud enough to wake us up anywhere between 10-20 times a night?
Some background info:
1) we live on 7th floor of a double brick, 8 floor high apartment block.
2) only 6 units hear the noise. 2 above and 2 below in one top corner of the building. no noise from floor 5 or below. loudest from top and dissipates as you go down
3) we have turned water and electricity off in all units and the noise continues. also had main water off and no change at all
4) have a rooftop exhaust fan which goes down a rise in unit next to ours and turned this off and noise continues
5) sounds metallic and not like concrete expanding/contracting. 2 engineers told us this
6) had 3 plumbers in and it definitely is not water
7) goes probably 80% of nights, seems to stop on cold windy nights. but still goes on warm rainy nights
sometimes goes in daytime around 11am to 3pm but only if sunny.
9) the roof is flat and is concrete with a black tarmac finish on it. there is nothing else in or on roof other than exhaust fan.
any ideas would be greatly appreciated.
thanks