Conservatory wiring

[akwoody2]

Hello,

so iv been asked to wire a conservatory that's been built, an electrician had stared it but didn't finish it due to health reasons. What I mean by started it he has chased in one twin back box and put one 2.5 t+e in. The other end of the cable is poking out the corner of the room through the mortar. My only guess is he was going to chase along the mortar to the next socket because it's built with exposed brick work, a very nice finish. The ring I will be tapping into is on a RCD, but i can't think of any other way to conceal the cable. I personally have never ran a cable under the mortar and never seen it done. Is it acceptable? If not how will I conceal the cable without damaging the brickwork?

I hope that made sense, if not then please ask me a question and I'll do my best to make it clearer.

thanks

 

[Knobhead]

they ain't used lime in mortar for donkeys. and it would probably take over 30 years for modern cement to degrade T/E. bang it in, get paid, next job.

After 24 years in the lime and cement industry I can assure you, you are wrong. It’s added to many mortars. Another fact, the cement is made using a calcining process.

As to lime damaging PVC, I’ve never seen it on any of our plants even though the cables would be covered in lime. Lime being hygroscopic draws moisture in from the air causing it to set like concrete around cables.

 

[telectrix]

After 24 years in the lime and cement industry I can assure you, you are wrong. It’s added to many mortars. Another fact, the cement is made using a calcining process.

As to lime damaging PVC, I’ve never seen it on any of our plants even though the cables would be covered in lime. Lime being hygroscopic draws moisture in from the air causing it to set like concrete around cables.

i stand corrected, then, years ago, i was told that cement would degrade cable. must be another old myth.

 

[shanky887614]

i stand corrected, then, years ago, i was told that cement would degrade cable. must be another old myth.

i thought the myth was about lime plaster they were telling everyone not to put cables in.

im my opinion though it was more to protect the cable from the trowel rather than it being de gradeded

 

[Knobhead]

If quick lime is used mortar can become warm as it hydrates. Put too much in and it will boil so that could be where it tale has come from. Slaked lime is usually used.

 

[telectrix]

so then, tony. can you give any reason why he should not chase a short length of cable into the mortar as long as it's horizontal between 2 sockets, thus being in a safe zone.

 

[Knobhead]

Can’t think why it shouldn’t be done, but I hope the OP is good at pointing.

 

[telectrix]

if bob the builder can do it, how hard can it be?

 

[DPG]

You don't still believe in that old myth do you?? lol!!

So what do you think cavity insulation is going to do??

So using your theory then, it doesn't matter which you up you put cavity wall ties then - the drip point can go either way without any problem? Daz

 

[Wiresandthings]

Just chop into the mortar, and make good, you wouldn't think twice if was plastered wall?? Chopped in plaster or mortar its still chopped in and covered over with either plaster or cement, a small oval conduit may just fit into the gap for extra protection etc job done

 

[Knobhead]

So using your theory then, it doesn't matter which you up you put cavity wall ties then - the drip point can go either way without any problem? Daz

I think you’re getting a bit confused. We were talking of a cable running horizontally, running vertically then there is the problem of suspended weight and condensation running down the cable.

 

[DPG]

No confusion. eng doesnt seem to think moisture can track across a cable from one cavity leave to another. Its only the same principle as moisture tracking across a badly installed wall tie etc. Daz

 

[7029 dave]

I do like a cavity.:stooge_curly:

 

[Engineer54]

So using your theory then, it doesn't matter which you up you put cavity wall ties then - the drip point can go either way without any problem? Daz

So please explain the theory behind cavity wall insulation, which bridges both inner surfaces over the whole area of the wall, and negates what way up the cavity wall ties have been installed!!

Cables within cavity walls cause damp to internal walls is a myth and always has been.... Bad mortar jointing (normally on old properties) and unprotected/unsealed old and new penetrations are the major causes of damp, nothing to do with any form of cables being run in the cavities...

 

[DPG]

Building regs, document C:

Cavity external walls​

5.12​

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Any external cavity wall will meet therequirement if the outer leaf is separated from theinner leaf by a drained air space, or in any otherway which will prevent precipitation from beingcarried to the inner leaf.​

Technical solution​

5.13​

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The construction of a cavity external wallcould include:a. outer leaf masonry (bricks, blocks, stone ormanufactured stone); andb. cavity at least 50mm wide. The cavity is to bebridged only by wall ties, cavity trays providedto prevent moisture being carried to the innerleaf (see paragraph 5.15 for cavity insulation),and cavity barriers, firestops and cavityclosures, where appropriate; and​

c. inner leaf masonry or frame with lining.

 

[telectrix]

clear as mud. typical building reg.