In your country, do you use pipe to run wire through very much?

[freddo]

there is a system available which uses standard steel conduit and the boxes have plain entries with a set screw to secure the conduit, i think it is called conlok.

I had a play with that once, didn't like it at all, the pipe entry holes were a bit big and the locking screws are tiny!

 

[Mike Johnson]

"Some Engineers" according to what the wall is used for, if its the inner skin of a cavity wall then is should be made good with a sand and cement this would be in the specification, in most case's the chase is left open for the spreads to fill with plaster, that is why "Some Engineers" are concerned, the inner leaf of a cavity wall can be 3.5N, 7N, or even up to 22N in a 3.5N block a chase filled with Bonding would be close the crushing strength of the block, but the Engineer can not rely on the site management or spreads to follow the specification, the days of the "Resident Engineer" have long gone and was the only way of ensuring the specification was followed, why Structural Engineers no longer have to spend six months on site before becoming qualified has baffled me for some time, this also applies to Architects, neither now days have any experience of what used to be called Buildabilty.

 

[nicebutdim]

Regarding you point about rewiring it's always an advantage but in reality there is no way the bigger size T&E we now use can be pulled through. Oval conduit is already user unfriendly for rewires. I also don't think it is necessary to allow for future rewires (unless damaged).

I doubt the original intention was to provide for future rewiring, but it would be one added benefit in some cases. Obviously not every section of old conduit will serve that purpose, but think of 20mm round conduit dropping to a 1G switch plate - that's going to be easy to pull a cable through if the need arises.

I take it there's no chance of getting two legs of that new Irish T&E through 20mm?

 

[LastManOnline]

I doubt the original intention was to provide for future rewiring, but it would be one added benefit in some cases. Obviously not every section of old conduit will serve that purpose, but think of 20mm round conduit dropping to a 1G switch plate - that's going to be easy to pull a cable through if the need arises.

I take it there's no chance of getting two legs of that new Irish T&E through 20mm?

If you pull 2 ends straight off the cable roller (no kinks), you will push them through a horizontal piece of 20mm pipe OK.

 

[Mike Johnson]

I doubt the original intention was to provide for future rewiring, but it would be one added benefit in some cases. Obviously not every section of old conduit will serve that purpose, but think of 20mm round conduit dropping to a 1G switch plate - that's going to be easy to pull a cable through if the need arises.

Your a lot younger than I thought, steel conduit drops where all about rewiring, using fabric covered cable needed this facility as the cable insulation deteriorated.

 

[freddo]

using fabric covered cable needed this facility as the cable insulation deteriorated.

I've come across quite a lot of both rubber and PVC insulated fabric covered conduit cable here, and it is often in excellent condition! Of course old rubber cables should be replaced as a matter or course...

 

[Mike Johnson]

There are always exceptions, but as you say you should always replace your rubber.

 

[Grant1987]

Your a lot younger than I thought, steel conduit drops where all about rewiring, using fabric covered cable needed this facility as the cable insulation deteriorated.

I’d disagree with you steel conduit is used to enable the use of single core cabling to provide a suitable means of protection and also enhance the space of wiring in single core cable you wudn be wiring a new build council office in twin and earth through galv it is single core so I don’t think age is a factor in your post

 

[Mike Johnson]

It is when you take into account when conduit drops where the normal thing to do, all switch's and sockets where cabled by a steel conduit vertical drop form the roof or floor void above or below, there where never any horizontal or zones, it was just straight drops to the sunken box, but as you say T&E did not exist it was always single core cable. It also made it simple, you just did not drill above or below a switch or socket.

 

[Grant1987]

It is when you take into account when conduit drops where the normal thing to do, all switch's and sockets where cabled by a steel conduit vertical drop form the roof or floor void above or below, there where never any horizontal or zones, it was just straight drops to the sunken box, but as you say T&E did not exist it was always single core cable.

All the drops I have done have gone into steel trunking and required a 90 degree bend sometimes included a set or double or even bubble at worst case lol I suppose different jobs have different specs but my experience with galv is that it’s galv all the way