Access to lighting wiring under loft floor

[David WE Roberts]

Two issues here.

(1) I would like to be able to access the wiring into the ceiling roses from above for maintenance, but I also want to floor in the whole loft with T&G loft panels. At the moment I can get at most of the wiring because the last third of the loft isn't yet floored in, and the area where the cold water tanks sat is also not floored in so I can slide T&G boards sideways to get them out. However when the whole lot is done, the lighting wiring will be concealed and getting at it could be a major operation.

(2) I really, really hate it when the ceiling rose has three or more sets of wires coming into such a small space. Endless fiddling to get everything to slide down for access, then slide back up again to refit the rose. Also doing it perched on a set of steps looking up.

So I would like to do one of two things.

Either just put some kind of inspection hatch over each ceiling rose - something low profile like a metal plate which can have stuff placed on it when not being accessed - or bring the wiring up through the floor into some kind of junction box so that each light fitting only has two wires and the wiring is easily available on the loft floor.

Both solve problem (1) but the junction box is an obstruction/trip hazard so although solving (2) it causes other problems.

How about fitting a dry wall box into the wooden floor and having some kind of junction in there, with a blank face plate? If so, what kind of junction? Can you get blocks of connectors (something more sophisticated than choc bloks) which are suitable, or even a proper junction box with strain relief which will fit in a wall/floor box?

Cheers

Dave R

[Nightjar]

That is what these are designed for:

Bignell

[David WE Roberts]

Ah - yes - forgot about those. Solves problem (1) but not problem (2)

[David WE Roberts]

So what is the difference between the 18mm and 22mm jig? Or is the only difference in the blanking plates? Do you need different cutters for 18mm and 22mm? Hmm..can see a replacement plate but no replacement cutter. You would think that if the cutter was the difference they would do a kit with 18mm and 22mm cutters.

Also, the video shows a plastic rim which fits into the routed gap and then takes the central piece of chipoboard but the pictures show plastic inserts. Does the full routabout leave the wood, but the mini-routabout use plastic plugs? Yes - looks like it.

So it all looks quite good, but if I haven't yet screwed the floor down then I can try other alternatives.

Such as a dry wall box, perhaps.

Cheers

Dave R

[Dave Liquorice]

But really designed for solid (chipboard) not T&G (planked) floors. With T&G I think I'd just have a bit of the boards that will lift out, ie remove the lower part of the groove(s) for sections between joists.

Which I think is more about strain relief rather than a box for the connections. The only cable that might not be clipped to the joists is the one dropping into the ceiling rose and that will have slack on it anyway. So if you change the fitting to one that doesn't need the rose you don't have to climb into the loft and shift all the junk that is over the access hole... Meaning that even that cable can be clipped adjacent to the junction box.

Personally I'd not want anything sticking up, like a blanking plate over a drylining box.

[Dave Plowman (News)]

The reason for these loop in etc ceiling roses is they are quick to install and economical with cable. But you're not forced to use them - you could do it the old way using junction boxes in a more accessible place. Or even just one larger box with all the connections in it - if you're not worried about cable costs or installation time.

But if you wish to provide access to the top of the existing roses before you've laid the flooring, cut out the size of trap you want, screw and glue battens to the underneath of the boarding round the outside of the hole and screw the 'lid' to them.

[Peter Parry]

and

[Dave Plowman (News)]

the boarding panels ain't down yet. Is it worth paying out for all that? I'd just cut out my own traps.

[David WE Roberts]

Yeah - not as fancy as the Trend setup, but looks as functional as the mini version. Still pondering over the ceiling rose/junction box thing.

[Nightjar]

We had a house with that: one very large box (about 12" square) in the loft with lots of connector blocks in it and cables going out to individual switches and lights.

Colin Bignell

[David WE Roberts]

Ah - T&G chipboard loft flooring packs i.e. smaller runs of chipboard which will go through the loft hatch. If you take away the T&G I think this compromises some of the structural strength. The T&G bit is quite substantial. I suppose I could interrupt the run at two joists and have a small panel of chipboard to lift - will have a look at that. Only need the underside of the groove on one side of the panel removed and it could well lift easily without losing too much strength. Drilled/hole sawn access hole is neater, but not as strong.

Not sure I completely follow this bit. If I need to check or modify the wiring at some future date, whatever system I use I will have to be able to get at it all. So AFAICS it is either having everything coming down into the ceiling rose (and still needing access from above to e.g. add another light) or having a simple light fitting and some kind of junction box in the loft. Either way I will need maintenance access at some point from within the loft.

Cheers

Dave R

[David WE Roberts]

> But the boarding panels ain't down yet. Is it worth paying out for all

Well, some of the boarding isn't down, some is down but coming up temporarily, and at some point there will be the issue of the light fittings at the front of the house which are boarded over. I will also (I have just realised) have to sort out ducting for the ceiling fan(s) in the bathroom coming up through the floor. Could do cutouts but a hole saw might be easier.

I quite like the flat bit which stops you going too deep :-)

[Dave Plowman (News)]

Same here - when I wired up this house mumble years ago I fitted 4 circuit Rotaflex track in both parts of the through lounge. Each of the four circuits on a dimmer - using a large grid panel. A 12" square adaptable box was the ideal way - my mate christened it Clapham Junction. So all the lighting connections are readily accessible. Not that I've ever needed to.

[Dave Plowman (News)]

My way of fitting battens to the underside round the outside of the trap will add back any strength lost. If you use the pivoting jigsaw method and take care you can make a perfect trap in one go.

[Dave Plowman (News)]

Just how often do you think you'll need access for 'maintenance'? I rewired this place some 40 years ago and haven't done any maintenance on the wiring since. Of course if you decide to alter the lighting - like say add extra lights or move them - an access trap only over the existing won't be that much help.

[Mike Barnes]

David WE Roberts :

Can you position the junction box on a wall? Then you wouldn't need access through the floor.

[David WE Roberts]

So what is the difference between the 18mm and 22mm jig? Or is the only difference in the blanking plates? Do you need different cutters for 18mm and 22mm? Hmm..can see a replacement plate but no replacement cutter. You would think that if the cutter was the difference they would do a kit with 18mm and 22mm cutters.

Also, the video shows a plastic rim which fits into the routed gap and then takes the central piece of chipoboard but the pictures show plastic inserts. Does the full routabout leave the wood, but the mini-routabout use plastic plugs? Yes - looks like it.

So it all looks quite good, but if I haven't yet screwed the floor down then I can try other alternatives.

Such as a dry wall box, perhaps.

Cheers

Dave R

*******************grrrrrrrrrrrrrrrrrrrrrrrrrrr**************** WLM treats this as a different thread. WM ond OE don't. Still can't get WLM to put chevrons against a previous post in a reply.

[David WE Roberts]

Well, if I have an access trap/hole and a means of cutting a small hole (such as the hole saw or the Trend router fancy whatsit) then I can get at the existing wiring and also cut a new access hole over the location of the new light fitting.

There may well not be a single simple answer.

[Dave Liquorice]

That is what I would do, gives you a nice big opening to work through. The hole saw linked to is only 110mm dia, you try getting a hand through

110mm dia hole to holed a wire or wires in place without considerably obscuring what you are trying to work on.

I envisaged the drylining box mounted into the floor. The blanking plate would then project above floor level.

[Dave Plowman (News)]

Sounds like you're determined to buy some new toys. ;-)

There never is. Drilling an access hole above when fitting a new extra light etc doesn't address having joists in the way of the cable runs.