New build cracking issues, guidance needed

Hi, first post so apologise if in wrong place

we purchased a new build in 2016 and have had issues with constant cracking sounds in the downstairs walls and ceiling when walking around upstairs. Today I decided enough is enough and poked my camera down a hole the builder previously made to rectify the issues.
I have posted an image of what I found but I’m struggling to find guidance on whether this is totally unacceptable. The downstairs toilet ceiling goes up to the wall board on one side of the stud wall but laps over the wall board on the other side but also protrudes over the height of the stud wall and looks to be the cause of my issue. You can see the stud wall and adjoining plasterboard at the bottom of the attached picture? Is this OK or do I finally have ammunition to push back on the builder? This is a pre-existing condition and if necessary I will involve NHBC but I need to understand what exactly is wrong here.. It doesn’t feel right but I’m not a builder..

thanks
Steve

I'm not sure what the problem is. What are you referring to when u say wall board? The plaster board on the wall?

Hi @williamglossop , thanks for taking the time to respond.
Yes, I’m referring to the plasterboard wall. If you look right at the bottom of the picture , you can see the steel studding, to the right, you can see the upright boards for the living room, to the left all you can see is the ceiling right up to the stud work and also higher than the stud work!, walking upstairs directly above this is causing all kinds of cracking and I suspect it is being caused by that ceiling compressing against the plasterboard below it. I’ve also noticed the ceiling in that room (it’s a toilet so circa 1m wide) is sloped. I suspect the other side will be with the wall plasterboard all the way up to the stud work, but cannot see this as it is the other side of that joist.

Is it just cracking noises, rather than actual cracks appearing..... however faint they may be, are there any visible cracks? I'd expect to see cracks in the toilet where the wall and ceiling meet..... if the problem is being caused by movement in the board.

There are lots of nail pops in there, I have also previous filled a crack all the way down a wall where 2 of the walls meet. (On the opposite wall to this though) honestly, this house is going to be the death of me, never buying new again lol.

Generally the ceiling lining boards would cover over the wall lining. But it does depend.

I would look at more basic installation issues first, screw pops are generally because they were done too deep, or the stud as it's drying out has moved slightly. Not big issues to rectify aslong as the fix retains the plasterboards strength, otherwise it will pop out again.

Looking at the picture, it looks as if they could have used a metal channel that could accomdate the ceiling lining each side (special channel for this) - but have instead used wooden noggins.

Should be consistent approach though right?
I get that nail pops happen.. and believe me, I’ve filled my fair share, but 4.5 years in? Honestly, the creaking is isolated to precisely where that stud wall is when being walked above it. I’m convinced of the cause, I just need to figure out how to get the company to deal with the issue.

If the glue joint at the top of the photo going left to right is a floorboard joint then the joint is unsupported and could creek.

The cracking downstairs might be unrelated to this creeking, but in the same photo you might have found an explanation if those noggins are only attached to the metal stud wall top and nowhere else - but those could be from remidals.

Could you get someone to walk around whilst you video through the access to see if you can spot any movement?