Junction Boxes , boxing in !!

[Spike1947]

Hi

Have just been to see a old sand stone house ( about 100 years ) than my mate has bought , he has removed all the latted ceiling to revile the joists , and the wiring , now he wants box in the cabling about 1/4 of the way down the joists .
Now the question is , there is a couple of junction boxes hanging there at the moment , now can he box them in , or does he have to change them for choc boxes etc ! .

I told him that is what he will have to do or get done , maybe I am wrong in that ! .

cheers

spike

 

[Andy78]

If they will be inaccessible then yes they should be of a type of joint compliant with the regs (section 526)
While the ceilings are down can these cables be replaced ? No joints is always better than hidden joints.

 

[buzzlightyear]

when the jbs where put in there must be floor boards you can lift up. when it needs testing .has long it is accessible.

 

[Spike1947]

Yes I agree with you , but it will be a job and a half to route new cables , I don't have the time to re-route them for him , I just thought a couple of ashley j804 which is 4 terminal 20amp would keep to the reg ! .

 

[Spike1947]

when the jbs where put in there must be floor boards you can lift up. when it needs testing .has long it is accessible.

I am not sure that any boxes under the floor boards are classed as accessible in that reg ! , could be wrong though .

 

[Deleted account]

While the cables are accessible it's worth the re routing.
If you don't have time fair enough maintenance free is an option, but i really think it's worth getting some one else who does have the time to do it.

 

[Dustydazzler]

Re route / replace the cables to eliminate the joint boxes

If this is not practical,

Then replace ant screw terminal boxes for MF boxes

 

[Pete999]

Hi

Have just been to see a old sand stone house ( about 100 years ) than my mate has bought , he has removed all the latted ceiling to revile the joists , and the wiring , now he wants box in the cabling about 1/4 of the way down the joists .
Now the question is , there is a couple of junction boxes hanging there at the moment , now can he box them in , or does he have to change them for choc boxes etc ! .

I told him that is what he will have to do or get done , maybe I am wrong in that ! .
If he want's to box them in they will need to be MF JBs, choc boxes are NOT a recognised MF jointing method, what is a Latted ceiling by the way, and why are the joists reviled?

cheers

spike

 

[markthebuilder]

I understand the regs changed Re junction boxes I’m guessing in the 16th I seam to recall it had to do with a theory of screws coming lose.. crimping was I believe a solution .if a straight joint ... hope so I know a few jobs that have defiantly been crimped.
So what’s the problem with as is just leave them. Is it because there had been hundreds of fires that were pinned down to failed junction boxes or is it to stop spurs being taken from the middle of a cable . I would genuinely like to be enlightened on this. After all we have all rewires properties in which the existing wording had functioned perfectly well for 50 years and the presence of jb’s was not the reaso the property needed rewireing.

 

[The Ghost]

It is axiomatic in wiring that the more connections the more failures are likely. With this is mind where you can eliminate connections or plan to have the minimum the better. There is a thing called thermal creep where the junctions of the connection (among other things) gets hot/warm then cold in a cyclical fashion. This causes movement of the screwed connection. Therefore there are quite cogent reasons that while it is accessible getting rid of JBs can eliminate a potential problem. In fact it is likely if you went into the older JB you may well find at least one of the terminations is loose from this.

 

[markthebuilder]

Axiomatic.. might become my new favourite word though I did find this alt definition that I thought was worth posting then again I have had wine.

relating to or containing axioms.
"1914 saw the first axiomatic declaration of exactly what constitutes a ring

 

[Andy78]

I understand the regs changed Re junction boxes I’m guessing in the 16th I seam to recall it had to do with a theory of screws coming lose.. crimping was I believe a solution .if a straight joint ... hope so I know a few jobs that have defiantly been crimped.
So what’s the problem with as is just leave them. Is it because there had been hundreds of fires that were pinned down to failed junction boxes or is it to stop spurs being taken from the middle of a cable . I would genuinely like to be enlightened on this. After all we have all rewires properties in which the existing wording had functioned perfectly well for 50 years and the presence of jb’s was not the reaso the property needed rewireing.

Yes screw terminals can come loose under vibration which can happen slowly, quickly, or not at all. I have come across many loose terminals in joint boxes in domestic situations, especially where they are not fastened down and cables not clipped to provide strain relief on the terminations.
I have come across much worse situations in commercial premises which are next to busy roads where the constant vibration has appeared to be a factor.
I have MET blocks in my van which have completely lost their screws from being all the way in from just a few months rattling around in a box in the van.

All joints that are not of a certain type should be available for inspection. This was definitely a requirement in the 16th final edition.

 

[FatAlan]

I’ve just renovated a 100 year plus sandstone cottage. Removed the lathe and plaster ceilings and unfortunately then all the floors and joists. Totally rewired with no junction boxes at all.
If he’s got the ceilings down take the opportunity to rewire. I bet he’ll be wanting to add sockets etc.