insulation over wires or not?
- Thread starter martlewis
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joe-90 said:
As long as I have been in the trade it has never been acceptable to put cables in the same notch as a pipe, so it would certainly be in need of an inspection to determin what remedial work is requied.
Not a clue.
Yes I do, as I'm sure you do.
+++ unhelpful part deleted +++
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joe-90 said:
Who says they can? I've seen plenty of scenarios where a cable has been in contact with a hot pipe, and it has severely damaged the cable.
In fact, I haven't seen many instances where cables have met pipes without detriment. And before you ask, no they were not run in the same "notch" as the pipes.
B
Big_Spark
Joe, if I may interceed...
+++ unhelpful part deleted +++ . As RF has said, it has never been acceptable, in the last 23 years at least, to install cables into notches in beams, they should all be drilled, and any DECENT spark will keep cables as far from pipework as is practicable.
Further, I know VERY competent electricians, and they NEVER work in a domestic premises, so your comment about that is blatently wrong and insulting to many.. +++ unhelpful part deleted +++
I could do the calculation for the Guy, your correct, I know how too and I know the data now from his latest post... +++ unhelpful part deleted +++
+++ unhelpful part deleted +++ . As RF has said, it has never been acceptable, in the last 23 years at least, to install cables into notches in beams, they should all be drilled, and any DECENT spark will keep cables as far from pipework as is practicable.
Further, I know VERY competent electricians, and they NEVER work in a domestic premises, so your comment about that is blatently wrong and insulting to many.. +++ unhelpful part deleted +++
I could do the calculation for the Guy, your correct, I know how too and I know the data now from his latest post... +++ unhelpful part deleted +++
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+++ unhelpful part deleted +++ . I don't install many these days but in the past I used to install a burglar alarm each day in domestic premises. That meant that every day I would have the chance to see how cables and pipes were laid under floorboards.
It is (or was) common practice to lay the cables in the same notch as heating pipes.
Since when has it not been permitted to install cables in notched joists? I seem to remember that there was some kind of directive (about 12 years ago) that metal plates be laid over such notches. I only ever saw one house so treated though.
Oh and Secure Spark. What kind of damage have you seen caused to cables by hot pipes? +++ unhelpful part deleted +++
Kettles are made of plastic with water at boiling point so how does a hot water pipe at less than half that temperature damage a cable? And if it were true then why are cables and pipes placed in close proximity to each other?
+++ unhelpful part deleted +++
BTW Bigspark - do you really think that a couple of feet of insulation will really cause a cable to overheat? What size cable do you use in lofts under the insulation? (where it all runs under the insulation). I'll be interested in seeing the calculation you are working on. You haven't asked if the cables travel under his floorboards with the central heating pipes yet. I thought you took ALL environmental considerations into account?
It is (or was) common practice to lay the cables in the same notch as heating pipes.
Since when has it not been permitted to install cables in notched joists? I seem to remember that there was some kind of directive (about 12 years ago) that metal plates be laid over such notches. I only ever saw one house so treated though.
Oh and Secure Spark. What kind of damage have you seen caused to cables by hot pipes? +++ unhelpful part deleted +++
Kettles are made of plastic with water at boiling point so how does a hot water pipe at less than half that temperature damage a cable? And if it were true then why are cables and pipes placed in close proximity to each other?
+++ unhelpful part deleted +++
BTW Bigspark - do you really think that a couple of feet of insulation will really cause a cable to overheat? What size cable do you use in lofts under the insulation? (where it all runs under the insulation). I'll be interested in seeing the calculation you are working on. You haven't asked if the cables travel under his floorboards with the central heating pipes yet. I thought you took ALL environmental considerations into account?
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Regulations, joe. In reply to your question about "do you really think..." Regulations qualified sparks like us have to adhere to. As has been said, crunch moment in court, "HAS THE DEFENDANT ADHERED TO BS 7671?"
How can you say that I have limited experience? How long have you been an estate agent? Have you got "limited experience"? You don't even know how much experience I have!
FYI, I've been in the trade nearly 20 years.
+++ unhelpful part deleted +++
Kettles are made of a special kind of plastic designed to resist high temperatures and even then, they eventually break down. Seen an old kemetal kettle?
Cables and pipes are not designed to be installed in close proximity- the regs talk in great length about detrimental influences and how every installation must be made with appropriate materials to allow for the immediate environment. Something you would know if you were up to date with 7671.
Standard PVC cables have a max temperature rating of what?
And that includes the running temperature of the cable.
As for the kind of damage, don't forget it is accumulative. Imagine a cable in close proximity to or touching a hot pipe. (Reckoned by you to be 50deg). Now imagine that cable in close proximity for many, many years.
I have seen rubber cables made brittle and pvc cables melted & scorched.
Yes, just by contact with a hot pipe.
+++ unhelpful part deleted +++
All I know is that you have insufficient knowledge to challenge us successfully (which is all you get off on, seemingly), and, as Softus has said, you are digging a deeper hole. Even Jim, who was on your side initially, has seen fit to write, "Your [sic] simply talking daft...."
Good day.
How can you say that I have limited experience? How long have you been an estate agent? Have you got "limited experience"? You don't even know how much experience I have!
FYI, I've been in the trade nearly 20 years.
+++ unhelpful part deleted +++
Kettles are made of a special kind of plastic designed to resist high temperatures and even then, they eventually break down. Seen an old kemetal kettle?
Cables and pipes are not designed to be installed in close proximity- the regs talk in great length about detrimental influences and how every installation must be made with appropriate materials to allow for the immediate environment. Something you would know if you were up to date with 7671.
Standard PVC cables have a max temperature rating of what?
And that includes the running temperature of the cable.
As for the kind of damage, don't forget it is accumulative. Imagine a cable in close proximity to or touching a hot pipe. (Reckoned by you to be 50deg). Now imagine that cable in close proximity for many, many years.
I have seen rubber cables made brittle and pvc cables melted & scorched.
Yes, just by contact with a hot pipe.
+++ unhelpful part deleted +++
All I know is that you have insufficient knowledge to challenge us successfully (which is all you get off on, seemingly), and, as Softus has said, you are digging a deeper hole. Even Jim, who was on your side initially, has seen fit to write, "Your [sic] simply talking daft...."
Good day.
B
Big_Spark
+++ unhelpful part deleted +++
If you go back about 40 years, then yes some cables may have been run in notched joists, especially the lead sheathed types, oh and DIYers.
But I have been in this industry for 23 years now and I have never seen cables installed in notches in the joists when the work has been carried out within the last 25 to 30 years.
+++ unhelpful part deleted +++
As for the calculation..might I suggest you inspect page 208 of BS7671 as it has a lovely example of the calculation and a nice reason why you use it...
If you go back about 40 years, then yes some cables may have been run in notched joists, especially the lead sheathed types, oh and DIYers.
But I have been in this industry for 23 years now and I have never seen cables installed in notches in the joists when the work has been carried out within the last 25 to 30 years.
+++ unhelpful part deleted +++
As for the calculation..might I suggest you inspect page 208 of BS7671 as it has a lovely example of the calculation and a nice reason why you use it...
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joe-90 said:
Ha, ha!
joe - I shall make you a very sincere promise.
I promise you that the very next time I come across an example of this, I shall post a picture of it.
I want you to promise that if I post a genuine picture where cables have been affected by hot pipes, you will admit defeat.
DEAL?
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securespark said:
You can do better than that. Get a pan of water. Bring it up to the boil. Cut off a length of cable and immerse it for an hour. Take a photo and post it here. If it doesn't look the same as before it went into the pan I'll admit that I am wrong. Deal? +++ unhelpful part deleted +++
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Big_Spark said:
+++ unhelpful part deleted +++ . You can put cables in notches if physical protection is provided (and yes you can still buy the covering plates).
Whenever I use cable I admit that I drill the joists, for the simple reason notching them weakens them whereas drilling a hole in the centre doesn't (at least nowhere near as much). But that doesn't mean that they CAN'T be notched. +++ unhelpful part deleted +++
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If this thread continues to deteriorate into needling and nit-picking, I shall delete unhelpful posts.
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