Junction boxes underfloorboards

Sep 30, 2017 38 Replies

That is one of the limitations of an EICR. You sample test the sockets for tightness (say 20%) but you do not usually lift floorboards to test JBs (and probably would not know where they were)

Recently I did a lighting rewire and I used JBs as I was only able to get a 1.0mm down the conduit to the switches and loop in loop out at the lights would not have worked due to the type of lights. All the jb's are together under a floorboard (more like a trap door now as it no tongue and groove left) in the airing cupboard. It took a few hours extra to get them there and not just fit them where it was convenient for me.

This trap door is noted on the installation certificate and the customer even labelled up the CU with the info.

The upstairs lights are done the same with all the jb's by the loft hatch on a panel above the insulation that the customer installed for me.

IME, one trade often damages the work of another...

They are better engineered, and in any case are *not* normally used at peak load. And they are reasonably accessible.

You only have to look at the creation of part P. If only painters and decorators had to belong to a 'professional body' pass an apprenticeship and pay subs to a private quango.

What a load of bollocks that is. It's done sweet FA for electric safety.

Well they can do an apprenticeship. It tells them when to have a tea break:-)

So do you check yours for security regularly? Or just wait until a connection fails as one must assume will happen if it has to be accessible?

You think a spring is immune from losing pressure due to thermal cycling?

Hi All

Decided to not go down the Wago route in the end and stick with screw down connectors. In terms of accessable and maintenance free etc. provided they are rated more than 32amp are there any other restrictions on what i can us e. Eg. One of these

formatting link

Or normal terminal connectors in a box (I have a couple of push lid ip44 bo xes hanging around eg)

Thanks

Lee.

I used a wiska box for spurring odd a ring final:

formatting link

(think it was one of that size, not the larger one)

I used 3 flat cable glands which provide strain relief:

formatting link

If you can clip the cables near the JB, you do not need strain relief, but in many ways I prefer the glanded approach - and it keeps it bug free.

formatting link

It's much bulkier than a round JB, but you can lay everythign out nicely, see that all the cores are under the screws and the box is liable, so less likely to be damaged by stepping or dropping something on it.

Thanks Tim. Is there anything stopping me using the other 2 options I mentioned? It would save me going to Screwfix as I have the bits already :)

Not at all - just any JB that does not have strain relief, must have the cables clipped fairly close to the box.

If you can do that, it's cool.

Yes I can clip the wire so should be ok. By strain relief does that mean the box has to have a way of gripping the wire eg those plastic strips that you screw down onto the flex in a standard plug?

Yes. If you can clip nearby (couple of inches or so) you are allowed to do without.

Do you have rats doing a tug of war under your floorboards? ;-) I've never secured cables going to a JB under the floor. Can't see any reason to.

Its more a future maintenance issue. Someone makes a circuit addition elsewhere and pulls on a cable etc creating a poor connection that is out of sight.

Something like the average cable clip isn't going to make any difference to a good hard pull - if anyone was stupid enough to do that.

A series of them will, unless you can pull them upwards. Especially if you stagger them a bit.

Surely no one is going to bother?

Would you pull hard on an existing cable to try and make it reach something?

I'd have said that restricted to some of Adam's worst apprentices.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required