Conduit under concrete floor?

[spaced]

Hi everyone

I've been asked to install 3 sockets in a conservatory that is currently under construction. I have a couple of questions. Firstly the only available point of supply due to the location of the build is from a spurred socket in the adjoining room. The spur is a single socket but has a fused connection unit attached to supply a dishwasher. I am planning to install a fused connection unit and then feed everything else from this as the customer informs me that he only requires the sockets for lamps. Would this be acceptable? Secondly, the customer has requested that the cabling is installed under the soon to be poured concrete floor. I would appreciate any advice on the best method to achieve this. My initial thought was to use 20mm PVC conduit. Would this be acceptable and are there any rules or regs on routing or number of bends etc.

Sorry about the long and probably ******* question.

Thanks.

 

[batty]

I would not be happy taking supply from that socket as its already been spurred off. How are they going to heat conservatory. It could be that in future the circuit could be overloaded by a future householder. Using conduit is fine. 20mm should be fine if you use singles but tw/e will be tight. Welcome to the forum also.

 

[spaced]

Thanks for the reply batty. I know that it's not a good solution but it is the only socket anywhere near where I need to be. The conservatory is having radiators installed - connected to the existing central heating system. Is it acceptable to run diagonally under the floor to limit the number of bends required?

 

[batty]

No regs book this evening but I think regs did change slightly in 17th but as long as its RCD protected should be no problem how you run conduit. How much screed is going over them?

 

[M107]

I'd go down the route of extending the ring into the conservatory not via a fused spur.

No problem with tube under/in the concrete.

 

[NozSpark]

I talked to the NICEIC tech help line on a similar problem,,, but in a ceiling.

Any cable that is <50mm and not in a safe zone requires earthed mechanical protection.. that is something like Steel conduit, SWA or flexishield..

the only place I could get cuts (i.e. 10m) of a flexishield type cable from was Batt cables,,,,

 

[sparkytim]

1.5mm to wire sockets???????????????????

 

[sparkytim]

I talked to the NICEIC tech help line on a similar problem,,, but in a ceiling.Any cable that is <50mm and not in a safe zone requires earthed mechanical protection.. that is something like Steel conduit, SWA or flexishield..

BRB 522.6.5

Cable installed under a floor ..........

(i) at LEAST 50mm

So conduit more then 50mm deep ok

 

[ianmacd]

1.5mm to wire sockets???????????????????

Why not if you have just come off a fcu?

 

[NozSpark]

In my case it was for lighting!

Just giving an example of cost and where you can get it

 

[M107]

I needed 2.5mm flexishield cable for a job (the green house one) & my wholesaler even had trouble getting hold of the stuff. One quote for 100mtr roll came in at