loft conversions

[loftyideas]

hi,
my normal electrician is unable to do this loft conversion, so called a new guy he has stated that because there is an onsuit bathroom and the existing fuse box has no rcd he cannot just connect to the existing ring main? and wants to change the whole fuse box!
Also he insists that he needs 75mm clearance around down lights in the PIR insulation and it then needs foil taping. the usual electrian drills hole through plasterboard and insulation into the cold airspace and just fits fire rated gu10s
Is this new guy correct or is my usual electrician out of date.
Help please

 

[ezzzekiel]

THE NEW CIRCUITS WOULD LIKELY REQUIRE RCD PROTECTION ANYWAY WITHOUT THE ONSUITE, OOOPS caps on, although there are various ways to achieve this without changing the c/u

 

[Spudnik]

Im afraid your new sparky is correct with the fact that there should be at LEAST 50-70mm clearance around any recessed light fitting, as they get very hot in use.

All circuits in a bathroom should now have RCD protection.

One way of achieving this is to instal a stand alone cu with RCD main switch with the circuits the bathroom is on.

 

[poheZ]

nearly all fire rated fittings are indeed suitable to be covered with insulation (something i only recently found out), if in doubt ring the mnufacturer. Its a more definate answer.

The RCD point is valid but a fusebox replacement is over the top, however we do not know what the scope of the works are and like the op pointed out all cables in walls less than 50mm require RCD protoection.

 

[Spudnik]

nearly all fire rated fittings are indeed suitable to be covered with insulation (something i only recently found out), if in doubt ring the mnufacturer. Its a more definate answer.

Are you sure about that???

I have just recently replaced some fire rated fittings (less than 12 months installed) as they had caught the insulation alight that had not been cleared properly.

IMO fire rated fittings only prevent the spread of fire.

I stand to be correct however.

 

[poheZ]

I am almost certain i read it in the latest edition of the NICEIC connect magazine.

It is of course wise to look at the manufacturers instructions as i may have jumped the gun in saying all fittings (fire rated) can be installed this way

 

[tenheads]

Are you sure about that???

I have just recently replaced some fire rated fittings (less than 12 months installed) as they had caught the insulation alight that had not been cleared properly.

IMO fire rated fittings only prevent the spread of fire.

I stand to be correct however.

have you ever had trouble with the lampholders overheating in these fire rated down lights??

 

[Spudnik]

Many times, and still do TBH.

 

[sparkylad]

Only a small number of makes of fire rated downlights can be covered in insulation --JCC do one ,they also do standard types that cant be covered---they have a kind of stand off shield and i think some sort of heat sink.and i beleive there are differing types for halogen and for LED. as a general rule if it doesnt say so on the box then it cant be covered

 

[loftyideas]

thanks for that
the fuse box is a sqd is it possible to fit a rcd individual fuse on the upstairs light circuit would that solve complete cu replacement.
would also fitting these new low energy clf downlights solve the gap problem, and what is the take on cold bridging over the now large whole needed with building control.
many thanks.

 

[loftyideas]

nearly all fire rated fittings are indeed suitable to be covered with insulation (something i only recently found out), if in doubt ring the mnufacturer. Its a more definate answer.

The RCD point is valid but a fusebox replacement is over the top, however we do not know what the scope of the works are and like the op pointed out all cables in walls less than 50mm require RCD protoection.

The celotex (PIR) type of insulation is indeed non flamable as the back of the downlight is exposed to free flowing cold air in the roof. Its not like covering the whole light with 200mm+ of rockwall and no air circulation as I see often in lofts before converting them. hence I have never questioned my usual sparky.

All walls could be considerd stud (sloping ceiling dormer over 180mm thick) the internal stud is 125mm with plasterboard both sides there is one bedroom (4 doubles) onsuite toilet shower(non electric) bason all plumbing is plastic up to the taps. usually we just channel down a suitable wall to an existing upper ring main socket and he connects from there and the lighting circuit took of the existing upper floor light connection. circuits tested and certificated job done. Never in 12 conversion projects have we had to change a cu and one or two have had the old black and red wire all tested and ok.

 

[blackiel]

Surprised your sparky runs off the old-any problems on old are his newly inherited problems,--on a loft conversion.id normally run a 16mm T&E ,(obviously depending on length)plus separate earth,up to loft,new board and all finals off that,much easier in the long run...IMO...Any future faults away from the loft cant be blamed on the install and any in the loft are local to the board!!!

 

[loftyideas]

Surprised your sparky runs off the old-any problems on old are his newly inherited problems,--on a loft conversion.id normally run a 16mm T&E ,(obviously depending on length)plus separate earth,up to loft,new board and all finals off that,much easier in the long run...IMO...Any future faults away from the loft cant be blamed on the install and any in the loft are local to the board!!!

wow surely you would check the existing ring and lighting was ok first, to run a new 16mm and earth up from existing cu to put in a separate cu in the loft conversion seems even more ott than complete cu repacement.
Just trying to get to the best solution here so is this the best solution for future loft conversions?

 

[blackiel]

Sorry mate, Dont think i made it clear,This is MY way of doing it,purely from experience and people telling me about problems theyve got three months later...Agreed testing at the start should verify anything wrong,but i dont like latching on to old (or even new) wiring that aint been done by me,more so for extensions or loft converts,i like being Future Proofed against scammers,theres plenty of them....Think about it,you chase down to the floor below,dont take a lot to carry on and find a route to the existing board from there,in my experience,the most it adds is a days labour,which if,you work it out,is a lot cheaper than going back because the bloke who owns the gaf added 5 new sockets 3 months later and now the whole house is Buzzing....Each to their own, mate,but ive been there and seen a lot,still in work,without any complaints or callbacks...

Be Lucky!!