Bangs !!!

[Moggaman]

Hi all,

I am 3 years in my new house. Double leaf block on edge with 150mm cavity. Wall plate and timber A roof. simple design. Outside it looks like a bungalow but inside there is 3 bedrooms upstairs and bathroom etc . So there is 9 roof lights in the roof ..5 at the back and 4 at the front . The roof rafters are 200mm depth , there is a lot of double rafters due to the the roof lights .. so I guess there is a lot of timber in the roof. The rafters are also supported by steel purlins/I beams 12m long which span from gable to gable. So here is my query. For the last 3 years , mostly in summer conditions , there appears to be a loud bang from the roof. Loud enough to wake us . It is way less obvious in winter but does happen. I insulated between the rafters myself and left no prisoners ie the insulation was tight.  I know it is not any water pipes or anything like that. 
my theory is that the timber is expanding and contracting in hot weather and the bang is coming from that..,. But it is very strange…any ideas…moved in July 22… roof built since December 21 

Do timber frame houses have this issue 

[Kelvin]

We had this in our previous house although mostly in the winter. In our case it was the large lean to living room ceiling that was attached to the main house. It was a single story room 11m x 6m and 3.4m ceiling with a large roof void above it (was an old cow shed) It had a complex set of  beams in the roof void the bottoms of which were exposed into the room. In the winter and in the evening when the room was cooling down it would make loud cracking and banging noises. Was a bit disconcerting but we were there for 8 years and nothing happened, no signs of movement or cracks in the plaster. 

[Moggaman]

8 hours ago, Kelvin said:

We had this in our previous house although mostly in the winter. In our case it was the large lean to living room ceiling that was attached to the main house. It was a single story room 11m x 6m and 3.4m ceiling with a large roof void above it (was an old cow shed) It had a complex set of  beams in the roof void the bottoms of which were exposed into the room. In the winter and in the evening when the room was cooling down it would make loud cracking and banging noises. Was a bit disconcerting but we were there for 8 years and nothing happened, no signs of movement or cracks in the plaster. 

Thanks for that. When I say bangs…. The sound is more flatter like the sound of hitting a wooden mallet off tree trunk …it’s not someone hitting a wooden malett of the tree trunk outside just in case people suggest that…. Last night for instance it happened maybe 15 times during the night 

[SteamyTea]

Thermal movement maybe.

 

Parents had a new house that had a banging roof when the wind came in from the west.

They sold it to a TV news reader. Always wondered why she looked tired.

 

[Bonner]

12m steels are going to expand and contract a bit. If they are bearing on something which doesn’t move it may make a noise depending on the materials. I have found noise problems with joist ends on steel. Solution was to create a slip joint with plastic sheet.

[Moggaman]

On 26/07/2025 at 09:48, Bonner said:

12m steels are going to expand and contract a bit. If they are bearing on something which doesn’t move it may make a noise depending on the materials. I have found noise problems with joist ends on steel. Solution was to create a slip joint with plastic sheet.

Maybe it was a bad detail.? The beams are 203x102x23 UB. Span from wall to wall -12m with - few intermediate supports. The end of the beams bear on the inner leaf of the block wall. These were mortared in before the roof went on. There are 2 beams  and they are continuous ie no splicing half way. I’ll post some photos for context. Also for context 9 roof windows, 4 at front and 5 at back and all rafters are 175x44 C16 Timber - doubled up at each roof light . 

[Onoff]

uPVC guttering, soffits and fascias are notorious for creaking...

 

?

[Moggaman]

2 hours ago, Onoff said:

uPVC guttering, soffits and fascias are notorious for creaking...

 

?

Yes I hear them too but it’s not them . Definitely… 3 1/2 years now … remarkable