The glazing units always seem to be a major headache on the builds I have seen on Grand Designs on TV, they always seem to be coming from Germany and are inevitably late.
Conduits in insulated walls
- Thread starter jamesph
- Start date
The glazing units always seem to be a major headache on the builds I have seen on Grand Designs on TV, they always seem to be coming from Germany and are inevitably late.
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Just to cover a few points…
48mm boxes screwed to the concrete will be 9mm below the face of the 57mm thick insulation. Add plaster board and the depth below face is 21.5mm.
The affect on the insulation is so small it is insignificant.
Remember that there is 157mm on insulation on the outside of the concrete (that’s 3 times more than on the inside and the concrete itself offers some insulating quality when the U value is calculated) it is unlikely that the back of the box will reach dew point – so condensation on the box is unlikely. I am considering a block of foam behind the box but I would go for 20mm mainly to bring the 48mm box almost flush with the plaster board. – I’m not worried about condensation. - Or as my mother-in-law used to call it "condescension"
I have already attached some 25mm conduit to a 48mm deep box using the coupler and bush. It will fit snugly. The front of the conduit would be in contact with the back of the plasterboard or very close. Obviously this requires the PVCu tube to be flexed slightly above the box but that does not appear to be a problem. The PVCu is un-plasticised so I don’t expect any reaction with the polystyrene.
If you look at the construction detail of the QuadLock panels you will see that they are held apart (or if you consider the fluid pressure of the poured concrete – held together) by plastic ties. The ties have vertical “plates” which sit about 8mm below the surface of the insulation and are spaced 1 foot apart both horizontally and vertically. Consequently there is a pair of these plates on a 1 ft. grid. The plates are about 30mm wide and 100mm deep. The plasterboard is screwed to these. In fact the load bearing capacity of the ties is sufficient to support large loads (can’t remember the actual figure and can’t be bothered to look it up just now). For instance the brick slips on the front elevation will be on a light steel mesh fixed to the ties with screws but of course the adhesive will stick to the polystyrene. I would not trust them to support a kitchen cupboard. You might have realised that this is an American system so it is in Imperial measure.
Just as a point of interest 1 inch is EXACTLY 25.4mm. This is the only conversion factor you need to know. So any measurement – even if its miles and kilometres – just convert to inches or millimetres and apply 1in = 25.4mm and the conversion will be exact.
Thanks for the tip about Yoozybox.
SimonH2: I have noted your disclaimer. How come you are replacing a CU?
Simon35: If Kevin was on my site he would be thrilled to bits doing a piece to camera feigning concern that I would be over budget over programme and overwhelmed – great television. Just for the record my wife specifically rejected the idea of going on Grand Designs because she did not want the entire population to see her face and hear her language when I do go over budget. Just joking – she never swears.
48mm boxes screwed to the concrete will be 9mm below the face of the 57mm thick insulation. Add plaster board and the depth below face is 21.5mm.
The affect on the insulation is so small it is insignificant.
Remember that there is 157mm on insulation on the outside of the concrete (that’s 3 times more than on the inside and the concrete itself offers some insulating quality when the U value is calculated) it is unlikely that the back of the box will reach dew point – so condensation on the box is unlikely. I am considering a block of foam behind the box but I would go for 20mm mainly to bring the 48mm box almost flush with the plaster board. – I’m not worried about condensation. - Or as my mother-in-law used to call it "condescension"
I have already attached some 25mm conduit to a 48mm deep box using the coupler and bush. It will fit snugly. The front of the conduit would be in contact with the back of the plasterboard or very close. Obviously this requires the PVCu tube to be flexed slightly above the box but that does not appear to be a problem. The PVCu is un-plasticised so I don’t expect any reaction with the polystyrene.
If you look at the construction detail of the QuadLock panels you will see that they are held apart (or if you consider the fluid pressure of the poured concrete – held together) by plastic ties. The ties have vertical “plates” which sit about 8mm below the surface of the insulation and are spaced 1 foot apart both horizontally and vertically. Consequently there is a pair of these plates on a 1 ft. grid. The plates are about 30mm wide and 100mm deep. The plasterboard is screwed to these. In fact the load bearing capacity of the ties is sufficient to support large loads (can’t remember the actual figure and can’t be bothered to look it up just now). For instance the brick slips on the front elevation will be on a light steel mesh fixed to the ties with screws but of course the adhesive will stick to the polystyrene. I would not trust them to support a kitchen cupboard. You might have realised that this is an American system so it is in Imperial measure.
Just as a point of interest 1 inch is EXACTLY 25.4mm. This is the only conversion factor you need to know. So any measurement – even if its miles and kilometres – just convert to inches or millimetres and apply 1in = 25.4mm and the conversion will be exact.
Thanks for the tip about Yoozybox.
SimonH2: I have noted your disclaimer. How come you are replacing a CU?
Simon35: If Kevin was on my site he would be thrilled to bits doing a piece to camera feigning concern that I would be over budget over programme and overwhelmed – great television. Just for the record my wife specifically rejected the idea of going on Grand Designs because she did not want the entire population to see her face and hear her language when I do go over budget. Just joking – she never swears.
Well as pointed out fairly frequently, the law allows it and I do not know a sparky capable of working to the standards I expect. Well actually, going by some of the pictures he's posted, there's one on here but I couldn't afford him. Luckily I'm in one of the council areas where the BC charges are more reasonable so it's "only" £150 (as I have the means of producing the sheets of measurements they want) to notify and make everything above board.SimonH2: I have noted your disclaimer. How come you are replacing a CU?
And I'm not completely without relevant qualifications & experience
For your interest SimonH2, where I live it's £314 to do the work associated with a building notice for say, the feed to my shed. Next LA over, £340! I'll be looking for a sparks.
Thread creep... Is changing a run of 6mm2 cable over to 10mm2 notifiable? It's to a shower from the cu so have I just answered my own Q?
Thread creep... Is changing a run of 6mm2 cable over to 10mm2 notifiable? It's to a shower from the cu so have I just answered my own Q?
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Ouch
Nearly forgot - you're in Wales, very backward* as far as Building Regs are concerned where I believe you have what we had until 2013. As OwainDIYer says, you are allowed to replace a damaged cable - but it doesn't actually (assuming you have the same wording as we had) say it has to be with the same size. Schedule 4, Part 1, (b) : Replacing a damaged cable for a single circuit only
Many have argued that this, and 1(a) which more or less says the same for sockets etc, means like for like - but the regs do NOT say that. Before the regs were relaxed (for us in England) in 2013, there were some "lively" discussions as to what was and wasn't allowed - right down to being able to (almost) completely rewire a house one cable at a time.
* As you are probably aware, in England the restrictions were very substantially relaxed in 2013. I assume because the authorities concluded that the previous version were overly restrictive to the point of being counterproductive and encouraging people to do work and say nothing - or not do work that would be beneficial. With that level of gouging on the part of LABC depts, the temptation to do work and say nowt - given that in many cases no-one would ever find out - is very high. I've two BR jobs open a the moment - £150 for the CU change I haven't started yet, and £90 for some minor structural works. If it would have been £400, £500, or more then it would have been really really tempting to "not realise" BR was needed
Mind you, plenty of people do seem to get away with ignorance - we've had an "abandoned" car in our street for 3 months, and I eventually reported it to the council as no-one seemed to know who's it is. Got a call back, it turns out it belongs to someone a few doors down, and apparently he was "mortified" when informed he couldn't keep it on the road without taxing it. I do have to wonder about someone who can sign a form where there's this big warning right next to where you have to sign (or tick to say you understand) without realising that if you SORN a vehicle then it actually has to be off the road
Not to mention the charlatans (aka fraudsters, criminals) in the trade who would deliberately misrepresent the rules so as to get people to pay them for work the owner could do themselves.
I thought I should report back.
Let it not be said that I can’t take good advice.
On Thursday I met with a highly recommended electrician who has agreed to work with me on my build. He specialises in mainly commercial work (factories etc.) and the larger new build housing projects. He will also be looking after two other properties on this site.
So that should rap up this thread. Thanks to all who contributed.
Jim
Let it not be said that I can’t take good advice.
On Thursday I met with a highly recommended electrician who has agreed to work with me on my build. He specialises in mainly commercial work (factories etc.) and the larger new build housing projects. He will also be looking after two other properties on this site.
So that should rap up this thread. Thanks to all who contributed.
Jim
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