Internal wall insulation- help!!

[paul notts]

Hi all.

I am required to do a complete rewire on a 1920s terrace property with 9" solid brick walls which is then to be replastered using 30mm wallboards dot and dabbed to the brick- that is 18mm insulation backed onto a 12mm plasterboard.

Sure many of you have done this many times so my question may have an easy answer.

Do I surface mount the cables to the brick cutting the insulation off of the board in a channel around the cables and call it clipped direct? Don't really want to be uprating cable sizes and then derating them for insulation!

Obviously there is a direct conflict between keeping the walls warm and the cables cool!

Any advice would be appreciated immensely as the reference methods in the regs do not appear to cover this situation definitively.

Many thanks in advance

 

[trev]

Ferg, not all insulated plaster board is foil backed mate. You can get stuff which has a layer of foam on the back, that's what's probably going on here.
Whether or not D&D adhesive will be any good for it is not our problem mate, that's for the boarders to sort out.

 

[ferg]

Ferg, not all insulated plaster board is foil backed mate. You can get stuff which has a layer of foam on the back, that's what's probably going on here.
Whether or not D&D adhesive will be any good for it is not our problem mate, that's for the boarders to sort out.

That makes sense.

Where I live, all external walls the plasterboard has to be foil backed.

Also d&d does'nt really exist as nearly everything is timber frame with block cladding.

 

[test electrical]

Chase the wall use 20mm conduit and plaster it into the wall and if you or really paranoid you could use galvanized.It will take twice as long but in fifty years time it will be handy to rewire

 

[Leesparkykent]

Chase the wall use 20mm conduit and plaster it into the wall and if you or really paranoid you could use galvanized.It will take twice as long but in fifty years time it will be handy to rewire

you could possibly loose the job with the cost of labour doing it this way.

 

[trev]

Chase the wall use 20mm conduit and plaster it into the wall and if you or really paranoid you could use galvanized.It will take twice as long but in fifty years time it will be handy to rewire

So despite the readily availability of things like capping and oval conduit you'd really go to the trouble of all that work?
Don't forget, in 50 years time how many of the points that you put in are still going to be in the right place for the owners of the property then? So chances are you'll have gone to all that trouble for nowt.

 

[telectrix]

in 50 years time, i'll be dust.

 

[trev]

in 50 years time, i'll be dust.

Nah, you'll live forever you old *******. You're pickled

 

[test electrical]

To think why the trade is the way it is, the worlds full of twin and earth champions and dry wall liners this why the 50 mm rule was about 20 years late for all them poor handy and diy people got jobs wiring council and wimpy houses in th 70/80s.

 

[Gavin A]

How would you normally install behind dot and dabbed plasterboard?

Do that.

Thinking about it, you first need to establish what type of insulation is involved. If it's PUR or polystyrene insulation, then you'd need to cable the cable as the PVC sheath reacts with PUR and polystyrene insulation and the 2 shouldn't be in contact with each other.

If it's PIR insulation then I don't think that's an issue.

 

[tazz]

Thats when Liverpools MP Derek Hatton spent all the council funds on cheaply built houses.

https://www.youtube.com/watch?v=H0tLFbA1PdE

 

[test electrical]

I know a so called spark who became an instructor because he was useless in the field and got 20 years out of it am still living on his mistakes

 

[paul notts]

Thanks to everyone who gave their advice here much appreciated.

One thing that's clear is that the regs do not address this issue!

Thanks again

Paul