VogonPoet's major bathroom refit mega-thread

[VogonPoet]

I have a few questions regarding a bathroom renovation I am planning. Rather than put them all in one big post I thought I'd split them up, the first questions are about RCDs and FCUs.

Background

Currently my house doesn't have a bathroom upstairs. Instead there is a sort of en-suite toilet (with a Saniflo unit to deal with the waste) off the master bedroom. The Saniflo is connected via a switched FCU, the feed for this is from the ring that runs the house sockets. This ring is on the RCCB protected side of the consumer unit (see photo).

Untitled

• VogonPoet
• 16 Apr 2015
• 1

The ceiling light in the en-suite toilet is part of the upstairs lighting circuit and is switched via a wallplate outside the room, this circuit is on the unprotected side of the consumer unit.

Planned changes

I plan to take some space off the master bedroom to expand the en-suite to a full bathroom. The wall separating the two (which currently houses the light switch mentioned above) will be removed and a new partition wall will be created.

It is my understanding that current regulations and safety considerations specify that any circuits entering a bathroom should be protected with an RCD. Does the RCCB at the consumer unit satisfy this requirement for the Saniflo? As part of the renovation the Saniflow is being moved to a new location in the room which will mean moving the switched FCU to a new partition wall. The new location is far enough away from the bath and sink that it will not be in a numbered zone. Can I continue to use the same FCU and run it from the same ring?

I believe an RCD will need to be installed to protect the lighting/fan/shaver circuit to the bathroom. Running a new cable back to the CU is going to be very difficult so would it be acceptable to use an RCD protected spur from the existing upstairs lighting circuit, feeding the bathroom via one of these fitted in the wall outside the bathroom (above the door). The fuse would be changed to a 3amp one. Would this be sufficient to satisfy the regs as far as RCD protection is concerned?

I am aware at least some of this work is notifiable and that it should be carried out by a competent person.

 

[ban-all-sheds]

there is a sort of en-suite toilet (with a Saniflo unit to deal with the waste)

You have my sympathy. I hope it continues to deal with it until it can be replaced with a proper WC.

As part of the renovation the Saniflow is being moved

It does seem a crying shame, given all the other work, not to seize the opportunity to get rid of it with both rubber-gloved hands.

Can I continue to use the same FCU and run it from the same ring?

Yes.

Would this be sufficient to satisfy the regs as far as RCD protection is concerned?

Yes.

I am aware at least some of this work is notifiable and that it should be carried out by a competent person.

Then you should have that person make design decisions.

 

[VogonPoet]

As part of the renovation the Saniflow is being moved

It does seem a crying shame, given all the other work, not to seize the opportunity to get rid of it with both rubber-gloved hands.

Getting rid of it depends on whether both the Local Authority and the Water company decide to play ball. I'd have to modify pipes on my land that run very near major shared sewers.

The pipes and electric runs are such that moving the Saniflo is going to be a relatively easy (though no doubt unpleasant) job so I'll do it as a backup plan. I can always cap the stuff off if I am allowed to run a proper soil stack.

Thanks for answering my RCD questions

 

[VogonPoet]

Moving on to my second set of questions; I plan to run a few different things off the 3amp fuse and RCD protected spur discussed above.

Ceiling lights

It will be a fairly small bathroom so I think three recessed downlights will be enough. The plan is to get 240v IP44 rated LED ones and put them in the correct zones. They will be controlled with a ceiling mounted pull switch in the bathroom.

Shaver socket/toothbrush charger

I've bought an MK shaver socket which is also rated for toothbrush charging (this one, although my model seems to be a later version that also has a toothbrush symbol printed on the front). The cable will run down inside a partition wall which is not going to be thick enough to bury the cable 50mm from both sides. The cable will be run in the safe zone above the socket. Am I right in thinking the use of the RCD will allow this without having to use an earthed conduit to protect the cable?

Fan/Humidistat+Timer/plinth lights

Here is where it gets a little unusual. My plan is to use a PIR as a switch to trigger a humidistat/timer which will control an extraction fan and some plinth lights. That way the fan will operate whenever anybody uses the bathroom (even in the daytime when the main lights won't be used) and the plinth lights should give enough light for quick midnight trips, again without having to switch on the ceiling lights. Also hopefully the plinth lights will look good

IP44 PIR switch, ceiling mounted in bathroom: http://www.screwfix.com/p/lap-indoor-ceiling-flush-pir/47121
Humidistat/Timer, installed in the bathroom but not in a numbered zone: http://www.amazon.co.uk/Swiftair-Humidity-Extractor-Bathroom-SHUMID/dp/B00ITX8840/
Fan, installed outside of bathroom: http://www.amazon.co.uk/Manrose-100mm-Standard-Mixed-Flow/dp/B005J3334I/
IP67 plinth lights, mounted in bath panel and sink vanity unit: http://www.screwfix.com/p/apollo-led-deck-light-kit-polished-stainless-steel-white-0-05w-pack-of-10/22392
Fan isolator, mounted on wall outside bathroom (beside RCD spur): http://www.screwfix.com/p/crabtree-6ax-3-pole-fan-isolating-switch/51728

I'm a bit worried about the fan noise at night, but the extractor I've picked is supposed to be very quiet (24dba at 3m) and is going to be installed in a sealed away area which should help dampen any sound.

The instructions for the fan say it is supposed to be installed on a 3amp fused spur. Does the RCD/3amp fused supply to the bathroom meet this requirement or will I have to fit an actual FCU into the circuit closer to the fan? Seems a bit redundant if so, but I'll do it if the regs say so.

I don't think any of the equipment individually draws a great deal of power but there is a cumulative effect, do you think it might get close to or exceed the 3amp rating for the spur?

I was planning to use the isolator to control the supply to the whole humidistat/pir/fan/plinth light setup. Will that be okay?

Can anybody think of any problems or obvious reg violations with the above?

 

[ericmark]

Does the RCCB at the consumer unit satisfy this requirement for the Saniflo?

If it is a 30 mA yes but there are also 100 mA versions which would likely not comply.

As part of the renovation the Saniflow is being moved to a new location in the room which will mean moving the switched FCU to a new partition wall. The new location is far enough away from the bath and sink that it will not be in a numbered zone.
Can I continue to use the same FCU and run it from the same ring?

There is more than the numbered zones because it is for the Saniflow likely yes OK. It will depend on the inspector he/she could look at 3 meter rule should not really apply to FCU only sockets but only the inspector can say yes or no.

 

[JohnD]

3 meter rule should not really apply to FCU only sockets but only the inspector can say yes or no.

What right has an inspector to rule in contravention of the regulations?

 

[EFLImpudence]

None - but we have had a poster recently who would do anything he is told for a quiet life.

Never assume those in charge know what they are doing.

 

[VogonPoet]

It is a 30mA RCCB so it looks like I should be okay on that front.

Any thoughts on my other questions?

 

[JohnW2]

3 meter rule should not really apply to FCU only sockets but only the inspector can say yes or no.

What right has an inspector to rule in contravention of the regulations?

As has been said ... none! However, I think eric was probably being over-cautious/pessimistic in what he said. The regs are pretty clear in indicating (by exclusion) that FCUs and LV switches are allowed anywhere which is not within the zones, and that (explicitly) the 3m rule applies only to sockets. I therefore doubt that an inspector would attempt to complain about an FCU which was outside of the zones, no matter how far it was from the boundary of zone 1.

Kind Regards, John