Diy dave, I've just seen that you never got an answer to your "but why is a choc box not compliant" question. There are really two questions. "Is it compliant" and "is it safe". The two are not quite the same - at least IMHO. It's not compliant because it's not rated as maintenance free, and a junction box in an inaccesible location needs to be. It really is as simple as that - rules is rules. Now the manufacturer of the choc box could pay to have it tested, and if it passed it would be compliant and we could use it. But that costs money, more than the manufacturer thinks is justified. So is it safe. Well the honest answer is we dont know 'cos its not passed the test that says it is if used in an inaccesible location. From what you've said I'd think it probably is safe, but I cant tell you that officially, and I certainly couldn't install it like that and give you the bit of paper that says its compliant. I can see its frustrating, but on the other hand Joe Public pays us to do a good job, and thats partially defined as being compliant with a set of regs. If, at the end of a job, I handed out a bit of paper that said "this work meets the required standard. Oh, except for the little bit under the bedroom floor, but don't worry, it'll be fine" I'd quite rightly get looked at sideways. If I found it in your house, and I'd be pretty sure it's diy 'cos a sparks is unlikely to do it so nearly, but not quite right, I'd probably officially tell you it was non-compliant and unofficially congratulate you on a decent job. I'd probably ask what else you'd been up to tho!