query on joists from a nooby

[justanoob]

Hi All,
I have only just about to qualify to be a sparky but still a few things a need to ask about as my tutor may have been just a robot and when it come to ans questions he seemed to have no idea. so anyway he mentioned that holes in a joist need to be 50mm from top and bottom but he said if the joist is not big enough than you can buy these steel plates that just knock on but i cant seem to find any on the net anywhere. so was wondering if someone has ever heard of these. thank you in advance.

 

[justanoob]

what you mean guitarist ??

 

[derek]

"Can't see nothing" implies you can see something. It can cause misunderstandings.

 

[TaffyDuck]

I never cut no notches in no joists.

 

[justanoob]

i dont cut notches in neither i just simply asked if these plates are ok if there is not 50mm from either side when i put an hole in the joist are the plates ok under regs etc etc. not nitpicking about the wording i use if i was asking on my punctuation and grammer then i would use an appropriate forum not an electricians forum. cheers

 

[telectrix]

how to win friends on a forum. :hanged:

 

[ayjay]

o,hh such simple stuff

 

[justanoob]

i know i have just read it back and not sound good sorry ppl it wasnt meant how it sounded im crap at this writing lark as you my have guessed lol, just trying to get my head around this and cant see in the regs about the metal plates to see if they are ok to use or just a waste of time, money and are not even recognised as things to use when the joist thru hole is gunna be less than 50mm either side. cheers

 

[onions1066]

Why would the hole be less than 50mm if you've drilled it
?

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o,hh such simple stuff

Oi ayjay no

 

[trev]

Never mind mate, continue to come here and we'll have you talking like Mr Cholmondley Warner in no time at all, it's all part of the service

One of my sons things was double negatives- I haven't got no money for example. Used to boil my wee, so I killed him.

 

[onions1066]

I won't tell anyone trev don't worry

 

[Stroppy]

I think a metal plate would be perfectly acceptable to protect a cable less than 50mm from the edge of a joist. If you think you can hammer a nail or put a screw through the flimsy ones then you need thicker ones (or a lighter hammer!)

 

[onions1066]

I think a metal plate would be perfectly acceptable to protect a cable less than 50mm from the edge of a joist. If you think you can hammer a nail or put a screw through the flimsy ones then you need thicker ones (or a lighter hammer!)

Or a shorter nail

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I think a metal plate would be perfectly acceptable to protect a cable less than 50mm from the edge of a joist. If you think you can hammer a nail or put a screw through the flimsy ones then you need thicker ones (or a lighter hammer!)

Or a shorter nail

 

[justanoob]

Why would the hole be less than 50mm if you've drilled it
?

onions i mean like e.g if i say drill a 25mm hole in the middle of a joist thats around 100mm which would leave 37.5mm at top and bottom something like that if this makes sense i asked tutor this question and he just said use these plates but i wasnt convinced that these would meet regs etc so i asked on here.

 

[Des 56]

The regs book likely wont tell you what you should use,you wont find the solution in there in a hurry
It may tell you that a cable has to be mechanically protected from nails or AK 47 rifle bullets or weeping women but not what to do about it

 

[onions1066]

How many 4inch floor joists do you come across? Not many