Access Through Air Brick

[Thenitwentbang]

I think I know the answer to this one - but thoughts and opinions would be really appreciated.

Running 4mm SWA out to a garage. Have completed the run to the garage and it is now at the house. This cable replaces a 2.5mm SWA that was already in place.

The previous cable had been run externally through a hole cut in a steel air brick!!! Whilst this is not a terribly good idea (given the potential for damaging the outer sheath), it does strike me that with suitable sleeving (a short length on 20mm conduit) this may make a usable exit point for the cable.

Can't seem to find anything in the regs, but it strikes me that this would be acceptable from a Doc A perspective - in that you are not drilling extra holes and further weakening the structure, the added conduit provides additional mechanical protection to the cable and, being an external installation, it will all be RCD protected in any case.

The location of the existing hole is very convenient to secure the conduit to a joist (almost right inside) and also well positioned to provide a neat run along a joist for cleating the SWA.

What's the consensus of opinion?

Thanks,

Ian.

 

[truckster]

Not sure but you might be violating building regs by reducing the size of the airbrick albeit by only the thickness of the cable. If the conduit is over 150mm it has to be earthed.

 

[Thenitwentbang]

Thanks Truckster - I did think that, so did consult Doc A and Doc F. Mind you, they may as well have bee written by Nostradamus!!!

Conduit would be plastic and the armour of the SWA will be bonded.

 

[truckster]

To be fair I would probably go through the airbrick

 

[Thenitwentbang]

Did think that. If I do go through the wall (which, to be fair, should not be too hard) I'll still have to fix some mesh or something over the hole in the airbrick to avoid providing a tradesman's entrance for furry little cable chewers!!

 

[truckster]

furry cable chewers in your tradesmans? ooh er missus o

 

[ExArmy]

i'd go through the airbrick

 

[Thenitwentbang]

Thanks ExArmy. Think it does make sense.

 

[Thenitwentbang]

furry cable chewers in your tradesmans? ooh er missus o

Normally, if I laid a cable, nothing would chew it Ooops - think we're getting 'off topic here'!!

 

[Electro-tech]

Is the airbrick means of venting for Gas appliances?

 

[Thenitwentbang]

Is the airbrick means of venting for Gas appliances?

Ah, a very good point - and, to be honest, one that I had not acounted for.

I would say yes - but not the sole source. There is another air brick the other side of the chimney breast. Gas appliance is a small 'living flame' fire.

But, I get your point - looks like the SDS is coming out.

Cheers,

Ian.

 

[topquark]

Cut a new hole for the SWA, sleeve it and seal it and either replace the air brick or have home owner replace the air brick.

 

[Thenitwentbang]

Cut a new hole for the SWA, sleeve it and seal it and either replace the air brick or have home owner replace the air brick.

Thanks topquark - decision made!

 

[topquark]

Yep saw that after I posted, ah well, right decision made. When replacing the air brick check if it needs to be another steel one.