I have seen the threads below on this issue and I wondered if anyone had any success with a resilient layer? Our developer re-screwed the floors, tightened/checked noggins. It has reduced the creaking upstairs but made no difference to cracking noise downstairs, the developer doesn't want to do anymore and the warranty holder has suggested resilient flooring.
Also can anyone recommend a specialist surveyor with experience of this issue who can help us find a resolution?
Resilient bars advance the interest of sound attenuation between the upper and lower floors. It is worth checking with Joist Manufacturer to make sure span/spacing is within loading tables; you can get this from them or on website.
Most likely issue is fixings....type of fixings is the most likely cause. NHBC Technical Standards refer to BS8212; in this document the fixings must have a minimum penetration into the supporting structure; should be 25mm so if you have 12.5 cm board minimum length of screw would be 37mm and so on. You also need to check screw is compatible with board...for example British Gypsum boards must have British Gypsum screws or they wont guarantee the system...and lastly, if screws are not requisite length or correct spec the complete configuration will not have been fire tested meaning short term fire protection is not guaranteed and that is required as part of the Building Regulations. Hope this helps