I see...
OK - that goes on my ignore list.
AFAIAC, DP (or TP for lighting triggered) isolator is sensible as you must be able to isolate a noisy or duff fan.
But this locking out is nonsense -especially as not every CU even sports devices that can have lock off tabs/locks fitted.
And yet TT supplies usually do not have DP MCBs and exactly the same applies to someone who is working off a metal ladder on an external lamp.
I agree with all of those.
And I'm not afraid to deviate from the regs if something is clearly not applicable in a certain situation - though I do like to check I have not overlooked a possible good reason (like now!).
Some aspects of AD F which might interest...
- AD F - "Types of work covered by this AD ... 3.2 ... erecting NEW DWELLIN GS and BUILDINGS other than dwellings, or carrying work on existing buildin gs".
- AD F - "NEW DWELLINGS" - "Fire Precautions 4.37 - Where ducting passes th rough a fire resisting wall/floor or fire compartment, the required measure s to ensure compliance with Part B of the BR MUST be taken."
- AD F - "NEW DWELLINGS" - "Table 5.1a Extract Ventilation Rates", "Bathroo m Intermittent Extract = 15 l/sec"
- AD F - "NEW DWELLINGS" - "Table 5.2a System 1 - Background ventilators an d INTERMITTENT extract fans". "Controls - INTERMITTENT Extract".
- "MAY be operated manually"
- "Any AUTOMATIC control SHOULD have a manual override to allow the occupan t to turn the extract on."
- "In a room with NO openable windor ... an INTERMITTENT extract fan should have a 15 minute overrun. In rooms with no natural light, the fans COULD b e controlled by the operation of the main room light switch."
COMMENT - So conditional on "NO openable window" and "SHOULD" is not "MUST" .
IN PARTICULAR NOTE...
- AD F - "S7. Work on **EXISTING** BUILDINGS"
- "Work should comply with the applicable requirements of Schedule 1 to the BR, and the rest of the building should be made less satisfactory in relat ion to the requirements than before the work was carried out (regulations 3 & 4 of the BR). "FURTHER, when a building undergoes a material change of u se, Part F APPLIES to the building or that part of the building which has b een subject to the change of use".
- "ADDITION OF A WET ROOM TO AN EXISTING DWELLING" COMMENT - a shower cubicle with level access & DOORS is not a wet room.
- "7.12 a. intermittent extract, as given in Table 5.2a and a background ve ntilator of 2500mm2 equivalent area"
- "7.13 to ensure good transfer of air, undercut of min 7600mm2 in the inte rnal door"
- "REFURBISHING A KITCHEN OR BATHROOM IN AN EXISTING DWELLING"
- "you do not make compliance with any other requirements of the regulation s ... worse than before"
- "if there is an existing extract fan (or cooker hood extracting to outsid e) you should retain/replace it. However if there is no existing ventilatio n system you need not provide one".
The last points are a rare glimpse of sanity - and the number of LABC/Kitch en/Bathroom fitters who get it wrong hilarious.
And indeed, if your kitchen contains a non room sealed combustion appliance with external flue, you may be prohibited from having other forms of extraction (depending).
I fitted a DP SFCU to the Xpelair; the fuseholder has a hole through that would take an itsy padlock, so I assumed it to be OK. The supply is via a pull-switch that manually activates the timer, then by
4-core cable to the fan - the L from SFCU being in-'n'-out of the C terminal on the pull-switch. No need for 3-pole thank goodness.
That would cost about 5x the fan every year. I checked mine after about 3 months and there was no muck at all (most of the areas that would be affected are visible anyway.
Why? You would have to train electrons know the difference.
Sent to your blueyonder address Adam.
Mike
On Sunday, January 18, 2015 at 12:23:25 PM UTC, snipped-for-privacy@btinternet.com wrot e:
2200 sq ft ... that is about 3x the floor area of a smaller 3-bed semi.Q - How... BIG... is this bathroom?
Bath or Shower w/basin
- Zone 1 - extends 0.6m horizontally beyond its limit and vertically to 2.2
5m- Zone 2 - extends 0.6m further & likewise
Shower w/o basin (wet room)
- Zone 1 - extends 1.2m from the FIXED shower OUTLET (the 1/2-bsp bit screw ed to the wall or ceiling, NOT the end of the flexi-hose)
- Zone 2 - none
- Sockets - Socket Permitted Zone starts at 3m OUTSIDE Zone 1
Outside Zone 2 you can stick wall mounted switches EXCEPT sockets. The only proviso is a) no washing down area and b) away from jets of water.
Aside: Interestingly there is a contradiction on the OSG p72 figure 8.3 bet ween Section & Plan ... Section shows a FIXED Zone 1 distance of 0.6m beyon d the partition ... Plan shows a distance of 1.2-Y-S or 1.2 MINUS Radial di stance from the fixed outlet to the inner side of the partition MINUS Thick ness of the partition. Someone has goofed unless I am going bonkers.
3m x 2m with a 1.2m x 1m entrance alcove in one corner. The door is 2.2m from the bath edge and 1.5m from the shower enclosure (around a corner).
So yes, in the bathroom, wall switches would work easily for everything as the highest wattage device is the towel rail at 200W. In the en-suite shower room the door is 1.3m from the shower enclosure so that just works too. For both, any device fusing could go in the attic on a board in a central location.
Change of plan, thanks guys ... a bit of wall chasing and find some nice-looking switches panels with legend slots in the plates so as not to confuse visitors in the bathroom ... is there such a thing?
Mike
Answered my own question ... use grid system switches and have the rockers engraved at about 20p a character. Even fuses, neons and key switches can be incorporated if really keen!
Mike
On Monday, January 19, 2015 at 10:19:29 AM UTC, snipped-for-privacy@btinternet.com wrot e:
You ABSOLUTELY need to ensure any switches (grid I presume) are outside Zon es and ALSO not subject to direct water spray. You can get fuse holders for grid.
Various Grid makers re MK, Legrand Synergy, Crabtree etc. Get the backbox that goes with them (40mm deep) because fuseholders and dim mers etc are very deep. Space can be quite an issue with Grid switches alth o this is all same circuit & most likely 1/1.5mm FTE. Even so you may find
3-way in 2G, 6W in Double-Ht-2G, 12W in Triple-Ht-2G eases wiring.If your fan is in the loft a) lockable switch elsewhere or b) local isolato r. If the loft is prone to damp / leaks, perhaps look IP rated switch.
There is some other Grid manufacturer who actually does 3P switch in a Grid form, they are sort of a slider-plate type - you can get 3P+Fuse on a 1G b ox.
Limit on chopping into a wall is 1/6th the leaf thickness which is 16.6mm f or standard house bricks. If there is blockwork much less than 100mm then d o NOT chop into it because it can make it unstable, thinking of 50mm & 60mm or so cinder block which has "structually reinforcing" plaster :-)
Thank you very much Adam, the Click mini-grid system looks great and at easy-on-the-pocket prices. Spotted the 3-pole fan switch (£3.14) as well as the rest of the range of the system:
Thanks to for the other tips; my roof space is nice and dry, splashes in the bathroom are exceedingly unlikely at the distances involved and I will be careful not to dig too deep when chasing the wall ;) Cheers guys Mike
Anyone here actually used the Scolmore Click MiniGrid?
I have purchased a set of kit to populate a 12-way plate with switches and fuses and having a devil of a job with it:
The supplier was a complete waste of space so I am in dialogue with Scolmore's Quality Manager but hearing about any experiences from others would be welcomed.
Mike
I use these at least once a week and find them the best Brand out there. No problems at all in fitting them etc. They are the easiest to install IMV.
Thank you Alan that's good to know. I can see that the conventional wall plates will work well but are you also saying you have found the
12 and 18 way plates too be easy to install too?The design requiring loose setting the yokes with the substantial internal screws then holding the whole lot together with four tiny self-tappers into a plastic frame just doesn't strike me as a good design.
Some of the issues:
The Scolmore Quality Manager has now established that the gaskets sent out with the polar white 12-way plates are all too small but has found a correct one to send me plus he is supplying sets of the missing screws so could not be more helpful.
I have replaced the terrible small yokes screws with decent countersunk head screws and fitted brackets so the yokes are screwed down tight to the back-box.
Mike
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