Sunken floor

[Shinji78]

Me and my partner have just purchased a modern 10 years old flat made in steel frame.
When we first visited the property we didn't notice anything special so we went ahead with the conveyances, but now that we have moved an placed our furniture we have realised how sunkene the floor is, specially on the living room.
If you release a marble next to a wall you can see how it rolls to the middle of the living room rather fast.
Out bookshelves are tilted towards us in a menacing way and not even the factory screws to adjust levelling are long enough so I have had to purchase a much longer ones so they look straight.
Outside traffic, specially lorries, makes everything to vibrate and even us walking feels like mild turbulences on a plane.

She is concerned about safety and I am trying to calm her down saying this is normal on this type on construction, but from my insides I am also concerned not so much for safety but for property valuation (we have put all of our savings on this flat).

The home report didn't say anything about this, nor any other documents or lender reports. Yet, I would like a professional on this matter to inspect out flat and tell us if is it there any reason to be concerned or (hopefully), there is nothing to worry about and this just an annoying thing we have to get used to.
In that case, what type of professional should I be looking for?

Did you have a structural survey undertaken when you purchased the flat? They are normally required for mortgage purposes. I would have thought a surveyor would be your first port of call.

Is it a modern high-rise? Concrete floor? I'd get the opinion of a builder first, & if he thinks it's anything serious, consult neighbours; look at a more invasive structural survey etc.

Are you ground floor?

Sorry for the answers so far.

This is a 4th floor from a 5 floor high building.
Since I have just moved in I haven't had the chance to speak to any of the neighbours.
The main structure of the building is 100% made in steel frame, so no concrete was use as far as I know.

We have the parking in the ground floor where steel frames are visible and they doesn't seems deformed or curved. I think the main structure looks fine and the sunken living room we have is due to its own weight and not having any extra steel frame in-between to hold it in place.

How much a builder could be? Has anyone contacted before so we can have an approximate price?

@weepingwillow22 - not true. You do not need a structural survey for a mortgage. It is highly advisable on particularly older properties but you don’t have too. We’ve bought two houses without one as they were both less than 10 years old. We had a homebuyers report & the banks own valuation.

OP - it would seem very unusual in a 10 year old building - do you know which company built it? You def need to try speak to neighbouring properties to see if they have any issues. Did you get a homebuyers report? Did the bank go & value? It seems peculiar a noticeable sinking of the floor wouldn’t be spotted. The previous owners would have had furniture in there during the reports. Obviously, any structural issues to your property has major implications to the ones below & potentially surrounding.. do you have home insurance? Make sure you have it in place just in case.

Unfortunately, heavy vehicle traffic is somewhat unavoidable but it shouldn’t make an entire building vibrate. How close to a busy road are you?!

OP, if you’re in the UK and the building has all building regs in place. Particularly as you had a survey done... seems v odd if really a significant & obvious issue.
Unless the issue is the floor covering rather than the floor itself?

Thanks again

There is a 2 metres wide sidewalk that separates the building from the road.
My insurance covers the structure of the building from specified damage such as fire, floods, etc. It doesn't says anything about construction materials.
In case that this deformation was caused by water leaking on the steel frames my take is that it would be a specified damage and in that case I should be covered.

The bank valued the property a bit higher than what we paid for it, but this building was raised by Housing Association and its initial price 10 years ago was half from what it is now.
That said, all finishes including the main door, boiler, etc are good quality, higher than standards.
Everything is well maintained and we don't see any of our neighbours selling their homes desperately because this is about to fall.

I think I will definitely contact a builder for an opinion.