We had a loft installed this year by a loft company. They created a double room & a shower room.
It hasn't gone that well. It took 5 months not the promised 3 to do the main bit of it. And they still haven't finished completely, so that is actually 9 months and counting.
Since finishing the "main bit" we have experienced leaks in the downstairs bedrooms from the new roof they fitted along with the loft. And their idea of 'finish' has been different to ours; they left gaps in the woodwork, a bent frame on the new velux window, a dented new radiator etc.... you get the picture.
They have corrected most of the things we complained about. However, we (DH & I) have moved into the loft this week. And I have realised how creaky the bathroom floor is, it sounds like a caravan. It is particularly bad around/in the shower.
We did complain about the floor creaks previously and they did nail it down moreso. However, this was once the shower tray was already in. And it is only since using it that we realise how bad it is.
We have since had a floor (which we paid for, as the agreement from them is they leave it ready to decorate) of lino laid in the bathroom.
I am not sure if we have any come back. We still owe them the last 5% which we aren't going to pay until the job is finished. However, pulling up the floor and shower tray/surround is going to be a large job.
I am also aware that I am overweight (size 22) so I wonder if they'll blame (or maybe think not say) my weight. However, Jack Spratt DH still makes it creak. I am not sure our weights are that different to most couples, just me being the heavier one 
.
I am just annoyed as every time I hear the creak I think of the shoddy job we feel they have done!!
Do we just have to learn to live with it? We won't be in the bathroom much each day I guess.....
TIA