Insulation Resistance Test

[JohnW2]

Within the build regulations concerning notching and holing of joists, there are certain areas where cables cannot be routed to comply to part A of the building regulations and their corresponding guidance documents.

Indeed- but as you go on to say, there are actually two issues, only one of which I was previously thinking/talking about. Firstly ...

If I were to route cables in existing holes that did not comply to those within the above parameters, and say someone decided that they wanted to but a 250mm drill/screw/fixing vertically in those areas that are not permitted to be holed/notched and in doing so went through one of my cables, that should not be there if in compliance to the relevant regulations, then who do you think the customer/that someone would be blaming for power loss and any injury incurred by my actions?

I hadn't been thinking/talking about regs/guidelines relating to the vulnerability of cables to damage. I agree that if you used an existing hole/notch which left cable vulnerable to damage, you ought to install mechanical protection. Mind you, perhaps unless it's a very new property, anyone who drills blindly into a joist on the assumption that there are no pipes/cables in positions which would not be compliant with today's regulations would be more than a little daft!

....Or say that I did use an existing hole/notch that was in an area that is deemed non-compliant as far stability of the structure, then that area of the joist collapsed, broke, snapped etc.. and my cable was within in this, again who do you think the finger would be pointed at as being responsible?

That's what I was thinking/talking about. I can't see how anyone, electrician or otherwise, could be blamed for the collapse of a joist due to holes/notches produced by someone else in the distant past!

On the other hand, if, in order to comply with current regulations, you drilled additional holes 'in compliant places' in a joist already somewhat weakened by having holes/notches 'in the wrong places' (e.g. wrong part of span) and the toist subsequently collapsed, then it would seem reasonable that you would be blamed. I think a lot of this has to be down to common sense, if necessary 'despite the regulations'.

Kind Regards, John

 

[PrenticeBoyofDerry]

I hadn't been thinking/talking about regs/guidelines relating to the vulnerability of cables to damage. I agree that if you used an existing hole/notch which left cable vulnerable to damage, you ought to install mechanical protection.

I would hole/route cables per regulations

Mind you, perhaps unless it's a very new property, anyone who drills blindly into a joist on the assumption that there are no pipes/cables in positions which would not be compliant with today's regulations would be more than a little daft!

There are plenty of daft folk about, I recently rewired a property where cables were installed within the floor voids and clipped to the perimeter joists, all tested off and floors/ceilings recovered. Then builder with long masonry bit, retrofitting wall ties, drilled externally inwards, through both leafs and cavity, through timber joist, through and through cables...

....Or say that I did use an existing hole/notch that was in an area that is deemed non-compliant as far stability of the structure, then that area of the joist collapsed, broke, snapped etc.. and my cable was within in this, again who do you think the finger would be pointed at as being responsible?

That's what I was thinking/talking about. I can't see how anyone, electrician or otherwise, could be blamed for the collapse of a joist due to holes/notches produced by someone else in the distant past![/quote]
And the proof that would defend me would be found where?
I would fear that I my not get a fair defence!

On the other hand, if, in order to comply with current regulations, you drilled additional holes 'in compliant places' in a joist already somewhat weakened by having holes/notches 'in the wrong places' (e.g. wrong part of span) and the toist subsequently collapsed, then it would seem reasonable that you would be blamed. I think a lot of this has to be down to common sense, if necessary 'despite the regulations'.

Or covering your own back and not allowing it to compromise oneself!

 

[JohnW2]

That's what I was thinking/talking about. I can't see how anyone, electrician or otherwise, could be blamed for the collapse of a joist due to holes/notches produced by someone else in the distant past!

And the proof that would defend me would be found where? I would fear that I my not get a fair defence!

I think you probably worry too much Certainly in my house, it's fairly obvious which holes have been there for decades and which have been produced more recently. I also think that all this talk about 'collapsing joists' is very hypothetical - as I think we all know, it's quite amazing what some people actually get away with (holes/notches in joists for 4" soil pipes or fan ducts come to mind)!

Or covering your own back and not allowing it to compromise oneself!

As I said if (despite my comments above about collapsing joists) a joist collapsed after (in the name of 'compliance') you had drilled 'yet more' holes in the joist, that would probably be the antithesis of 'covering your own back' - I imagine that it would be very difficult for you to find a defence in such a case!

As I also said, I really think that a degree of common sense is sometimes appropriate!

Kind Regards, John

 

[PrenticeBoyofDerry]

As I said if (despite my comments above about collapsing joists) a joist collapsed after (in the name of 'compliance') you had drilled 'yet more' holes in the joist, that would probably be the antithesis of 'covering your own back' - I imagine that it would be very difficult for you to find a defence in such a case!

I don't think you have understood my posts, I would not drill more holes, if I thought it would compromise the structure of the joist, I would find other ways to comply to the regs!

 

[JohnW2]

I don't think you have understood my posts, I would not drill more holes, if I thought it would compromise the structure of the joist, I would find other ways to comply to the regs!

Fair enough - but that could often be extremely difficult, couldn't it? What would you do if the customer was not prepared to pay for the additional time and effort (and maybe even materials) involved in utilising a very difficult and/or circuitous route?

I suppose it really comes down to what you mean by "if I thought it would compromise the structure of the joist" - i.e. are you referring only to a situation in which you really believed that the joist's structural integrity would be significantly compromised by additional holes?

Kind Regards, John

 

[PrenticeBoyofDerry]

Fair enough - but that could often be extremely difficult, couldn't it? What would you do if the customer was not prepared to pay for the additional time and effort (and maybe even materials) involved in utilising a very difficult and/or circuitous route?

He could either take my advice or I pack my tools away.
My contracts have a clause that states that all relevant building regulations will be compiled to.

I suppose it really comes down to what you mean by "if I thought it would compromise the structure of the joist" - i.e. are you referring only to a situation in which you really believed that the joist's structural integrity would be significantly compromised by additional holes?

Well each situation could vary, and an assessment on what is presented before you would be required. And consideration on, as previously stated if the location is going to come under a greater load than previously.
In this case the addition of loft boards and potentially stored items or the space being used as an additional room would be a worthy consideration to take.