Extractor Fan, wiring via cavity wall?

[Tarquin]

I'm getting ready for an electrician mate to put an extractor fan in the downstairs bathroom and thus far have lifted the floorboards in the bedroom above to expose the light fitting.

Rather than mess around channelling a groove down the wall to accept the wiring can the cable be fed down the cavity wall (there's no insulation) and wired to the fan that way? It's only got to drop about 18"....

 

[flameport]

No.

Cut a channel in the wall.

 

[Tarquin]

Thankyou.

Have you considered becoming a marriage guidance counsellor?

 

[securespark]

Why?

Because marriage guidance counsellors have to be very precise and direct with their answers, in order to avoid confusion?

 

[Tarquin]

No because counsellors give reasons for the information they impart so as not to avoid confusion.

Try this.......

1: Don't drink and drive..

2: Don't drink and drive as your faculties will be impaired and you'll have an accident.

Comprende?

 

[riveralt]

No because counsellors give reasons for the information they impart so as not to avoid confusion.

This isn't a counselling session its a response to a question. I don't remember seeing 'and explain your reasons' in the question.
But since you seem to need a reason to move forward....

Think about what the purpose of a cavity wall is?
At least two spring to mind - and remember bricks are porus.
They create an air gap which aids insulation.
They create an air gap which stops moisture penetrating the inner wall.

Put a cable in the air gap then penetrating moisture will use the cable to follow the route to your inner wall plaster and hence damp.
Also electricity and water do not mix.

And if you want it in black and white then looked at the Building Regulations approved document C ... 5.13b.

 

[bernardgreen]

so as not to avoid confusion.
~~~~
2: Don't drink and drive as your faculties will be impaired and you'll have an accident.

But it is also said that drinking coffee reduces the risk of an accident when one is tired and driving.

Come on. be precise and avoid confusion.

 

[Lectrician]

Although, if the hole was drilled at an angle from below the floor boards into the cavity, and the cable dropped the 18" to the extractor, the cable would remain tight to the inner leaf of the wall.

With the fan hole open you could also install the cable without causing damage to it.

Not that I would like to see it done, but there was an NICEIC article on it a while back with regards conservatory dwarf walls and the question being raised often on their tech help line.

 

[Tarquin]

No because counsellors give reasons for the information they impart so as not to avoid confusion.

This isn't a counselling session its a response to a question. I don't remember seeing 'and explain your reasons' in the question.
But since you seem to need a reason to move forward....

Think about what the purpose of a cavity wall is?
At least two spring to mind - and remember bricks are porus.
They create an air gap which aids insulation.
They create an air gap which stops moisture penetrating the inner wall.

Put a cable in the air gap then penetrating moisture will use the cable to follow the route to your inner wall plaster and hence damp.
Also electricity and water do not mix.

And if you want it in black and white then looked at the Building Regulations approved document C ... 5.13b.

No, but it's common forum etiquette, hence your more detailed reply for which I thank you.

 

[Tarquin]

Although, if the hole was drilled at an angle from below the floor boards into the cavity, and the cable dropped the 18" to the extractor, the cable would remain tight to the inner leaf of the wall.

With the fan hole open you could also install the cable without causing damage to it.

Not that I would like to see it done, but there was an NICEIC article on it a while back with regards conservatory dwarf walls and the question being raised often on their tech help line.

I can keep the cable tight to the inner wall. Could even drill down through the block as at that point we have a 2" offset, the upper floor being constructed using 3" blocks sitting on a lower floor of 5"ers.

However, if it's against the regs I wouldn't ask, nor would I expect my mate to compromise.