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Thread: How to find a plastered junction box

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    How to find a plastered junction box

    F%^& ... F%^&* ... F^&* who does this shyte ???

    So I am busy with a double storey domestic rewire ... couple hours to rewire the ground floor ... pull in neutral and earth wire to the each switch ... and we done ... ran into one Tee piece which was plastered closed on the ceiling ... took out the metal detectors ... easy find ... scan the ceiling ... find where the it tees off ... out with a 4 lb hammer and boom there it is ... remove the cover ... pull the cables and we done.

    Then we started the 1 st floor ... removed the lights and switches ... start with the 2 way switching on the stairwel ... removed the ground floor 2 way switch and pulled on the wires ... wouldnt even move an inch ... check the wires in the switch upstairs and downstairs ... one has an additional neutral and the other an additional live ... straight away it tells me that there is a junction box somewhere in the wall or ceiling ... cut all the wires and switch on the power ... to make matters worse .. .the feed from the DB is also in the junction box ... out with the metal detectors and a pencil following the wires up the wall and onto the ceiling ... scan left to right to see if the gap in the beeps increases ... indicating that there is an object wider than a pipe ... nothing ... out with the bright torch and the hammer ... tap on defects on the ceiling ... the sound would change if ther ewas a junction box ... nothing ... next try pull on the wires as hard as you can hoping a joint will release and we can measure the piece to get and idea of distance to the tee/junction box ... wires just snap off (old material wiring ... hence the rewire)

    I considered smoking a joint and blowing smoke into the conduit ... like we do when we trying to identify pipes to or from a DB ... works like charm ... but in this case ... it seems the box is buried deeper.

    Tomorrow I am going to pour water down the pipe and leave it to stand for a while ... hoepfully it will create a wet spot on the roof within a couple hours ... I will take my thermal imager with to site ... to scan the ceiling once we have poured the water ... it might pick up a slight temp change ... other wise I will chop open where I know the pipe is running and use a blow torch to heat the pipes and track the piping like that.

    Any other tips?
    Comments are based on opinion...not always facts....that's why people use an alias.

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    Maybe use boiling water down the pipe, it may be quicker or easier to see the thermal image then
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    Quote Originally Posted by Justloadit View Post
    Maybe use boiling water down the pipe, it may be quicker or easier to see the thermal image then
    Thanks ... good idea.

    Some might be thinking why not just run a new wire and that would be the quick solution ... unfortunately its not that simple ... its a double storey ... with a concrete stairwel in the middle of the house.

    Something I thought about last night ... the plugs and lights where on the same circuit before someone started doing modifications ... I did look for plug sockets on the wall in line with the pipes I found yesterday ... today I plan to open up all the socket outlets ... the toilet light ... passage lights and stairwel lights are on the same circuit ... the toilet light onlyhas been rewired and had a TEE box where they have connected a piece of surfix ... the box I am looking for is where the DB ... the toilet and the passage lights connect the old wiring to the new wiring.

    This is why quoting for domestic installations is financial suicide ... I would bet the entire cost of the project that the electrical company who did this shyte is a registered electrical contractors ... you can see by the steel piping ... the bitumin tape around the pipe ends etc.

    The challenge for today is to find the junction box and figue out why the plug socket for the microwave trips at 14mA and connect the sonoff smart light switches ... fortunately I have dustless chasing equipment .. .so if I dont come right by lunch time ... tomorrow we will cut thni shallow slots with the dustless grinder and fit twin+e from the DB to the toilet light ...passage light to a junction box on the outside wall ...then up the wall to the roof space.

    A note ... Sonoff smart switches are only rated to 2 amps ... not 16 amps like normal switches.
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    Found it in the kitchen above the cupboards ... a 3 way box ... feed from the DB ...to the 2 way switch and the other side to the upstairs switch ... which feeds also feeds the lighting circuit upstairs.

    How did I find it ... I traced the pipes in the concrete ...using a pencil to mark the route ... using a bit logic I created a pipe route in my head ... what seem to make sense was only 80 % correct ... I then went upstairs and pictured the deck without the walls ... thats when i started looking in the kitchen ... instead of bring the pipes into the passage area ... they installed the pipes up through the wall into the kitchen area to a junction box then back through the wall into the stairwel area.

    Pulled some of the wiring out to make sure they were loose ... tomorrow we replace the old steel (16 mm split ) piping with PVC conduit and rewire upstairs.

    What a relieve ... if i didnt find the junction box ... it would have meant chasing tomorrow.

    Imagine quoting for a job like this.
    Comments are based on opinion...not always facts....that's why people use an alias.

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    It seems there are a few more junction boxes nicely concealed in the concrete slab ... a pity the plasterer did such a good job of hiding them and then the painter used a rough finish paint ... doing a lot of tapping and tracing
    Comments are based on opinion...not always facts....that's why people use an alias.

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