Thanks for an informative video thats not unnecessarily long! Straight to the point. Came with a question and left with an answer. Quite rare these days.
So basically: 1. Hole position is between 25%-40% of the joist length 2. Hole diameter not more than 25% of joist height. 3. Holes at least 3 hole-diameters apart. :)
In the situation were you have 100mm joists installed but you need to drill holes for cable access you would just need to install steel plates accross the top and and underside of the holes to give additional streangh to the joist.
Such a brilliant video although I know the basics of wiring didn't know about the regs for drilling holes. Friend building his own house soon so this will help big time
What country is this ? didn’t learn this in Australia so guess its not an issue Drill in the middle and don’t drill to close to the edge sounds fine to me
Great stuff. I was just thinking today what the issues are with drilling additional holes in the floor joists to run new/replacement cabling. Nb: In the building industry all lengths (On a housing site for definite) are stated in mm. cm and meters just confuses things. Nnb: Generally pref to drill as high as possible on the floor joist to conserve room height below (Building regs) if you have exposed beams and will infill them to hide the cabling.
Great videos. How does it work if the room you are in in this example was is split into two. I'm assuming it just means that the cables have to be run on the outer side of the room where the joists meet the wall? Also if you're coming length ways against the joist do the cables need to be fixed onto the joist or can they sit in the void this would be for an existing site with ceilings
Hi I read that holes must be three times their diameter apart. Would this mean if a plumber has drilled a 28 mill hole for pipe then my hole for wires would have to be at least 84 mill away from it thanx
Hi thanks for your excellent video. If the loft space was not going to be ever boarded over do the regs allow for the cables to be clipped directly on top of the ceiling joists? Best Regards Chris
Hi. Try and avoid placing cable on the top of joists in lofts as people can stand on them when accessing the roof space. Best to route the cables along the apex between the roof line and the joists in the roof as no one stand in the area. Thanks for commenting and watching. Gaz 👍
If you were talking to any other trade, or profession, what you are calling the 'Width' of the joist, would be referred to as the 'Depth' . Confusion might ensue especially if you were having discussion with structural engineer.
Good video. Thanks. You'll often see cables strung from joist to joist through holes, with no support between the joists. Most cables need support every 250-300mm (on-site guide) and yet joists are typically 450mm apart. Should we be doing something to support the cables in between?
Hi great question. Appendix D page 141 On-Site Guide the title of table D1 is spacing of supports for cables in accessible position... I would class cables through joists in floors or ceilings as not accessible. Thanks for watching and commenting GSH Electrical 👍
Can you do both sides of the joist like that or just pick one? Does the load bearing joist count as a support, would it still be the entire length or just to that support?
Hi. I hope this helps 👍 www.elecsa.co.uk/Documents/Contractor-Documents/Pocket-Guides/Pocket-Guide-20.aspx Thanks for commenting and watching GSH Electrical
Great video. Would this be affected by what the joist was supporting? For example a truss system? Also, would the same apply to every consecutive joist as I think I will need to drill through 8-10 for the cable run
Hi, where is the safe zone on the ceiling to drill the holes for downlights( this is in a flat without joists? )And can the cables run flat or resting in the ceiling using twin and earth cables without trunking ? Thanks
Great video - moved out of domestic sometime ago now management and about to wire my new extension very helpful, can you do a video on zoning in kitchens lol
Thanks for the kind comment this video applies for cable zones th-cam.com/video/LBf9dlI5JAg/w-d-xo.html All the best and thanks again for watching GSH Electrical 👍
Centre of holes 4 X diameter of hole apart, and only a quarter of thickness of joist, in the 25-40% region and the 60-75% region of length. Interesting, not likely to need it ever, but I like to know rules, helps me be more of an intelligent client. Maybe that's a really useful topic to cover on one of your channels, as you may be professionally focused, but I'd bet you have a fair number of consumers watching too and it would help good sparks and help customers find them as until recently I really struggled.
Really appreciate these great videos, what is your take on the domestic installer courses which are held over a period of about a month, which provides enough knowledge and skill to work in the domestic sector not commercial, they claim once these courses are passed a person may register onto a scheme, are these suitable for a person who simply wants to work in just the domestic sector? Many thanks
Hi. All I will say on the domestic installer course is it take my learners 2 years to get it and a minimum of 3 6 hours site visits 👍 plus a portfolio 🤔. My learners earn it thanks... for the question Gaz
It gives you the section where compressive & tensile forces are less. Somehow they've worked out that it's always from a quarter of the way in to almost halfway across the joist.
Hi am I correct in thinking that after drilling in the prescribed zone you are permitted to bend and clip cable in order to place a socket on a wall. And that the holes ate for placing long runs of cables.
Check out Metwood Joist Reinforcers www.metwood.com They allow up to 4" holes in 2x8s, 6" holes in 2x10s and 2x12s 1 hole per joist only allowed. They are engineered and or code approved.
I’m gonna drill in the middle :) Don’t laugh. I just moved in this house and the holes are on the edge. That’s when the previous owner decided to secure the cables. There’s quite a few dangling under the joists in the crawl space.
@@GSHElectrical all good just the differences between different videos on youtube some come across as loud others like yours lower but mostly due to im guessing the distance from your camera cheers
I'm a structural engineer in alaska. this practice needs to stop, we've had quite a few roof failures and having some electrician hacking your trusses with sawsall to route cable is out of control
Where did the IET get the idea of a zone to drill in? There appears to be no good structural reasoning behind it. From a structural point of view, you just need to avoid the lower section of joists, which resist the bending force from superimposed and dead loadings.
Hi. I don’t make the rules but often trades drill holes anywhere they need them causing potential issues over time... thanks for watching GSH Electrical
Seems a bit dangerous to turn joists into swiss cheese like this, I would be concerned about one 25mm hole in a joist that small let alone multiple holes in sucession!
Hi. I understand what your saying but the information in the video conforms with BS7671 and is required by my learners. Thanks for watching and commenting all the best GSH Electrical
This comes ultimately from the building regs and the specifications take this sort of thing into account. In that sense the joists size per span are over-engineered.
Ever seen a castellated steel beam? Think if it as similar to that. The amount of steel is the same but the span can be longer compared to a standard RSJ of solid steel. The height is increased and it has holes but is stronger. How come...?
@@GSHElectrical so basically do what the IET says and ignore structural loading calcs, timber integrity, or common sense? Good advice thanks for the clarification.
Thanks for an informative video thats not unnecessarily long! Straight to the point.
Came with a question and left with an answer. Quite rare these days.
Another excellent informative video. Thank you, Kam
Thanks 👍🏻
So basically:
1. Hole position is between 25%-40% of the joist length
2. Hole diameter not more than 25% of joist height.
3. Holes at least 3 hole-diameters apart.
:)
finding this video years after its published! very informative and very clear as to the regulation.
Massive thanks 👍🏻
Great vid. Obviously the academics that decided this spec have never worked on site😄
They never do, i have and i have never ever seen anyone doing all that crap on site. You wouldn't last a week if you did😃
In the situation were you have 100mm joists installed but you need to drill holes for cable access you would just need to install steel plates accross the top and and underside of the holes to give additional streangh to the joist.
Simple and clear. Great video.
Thanks
Such a brilliant video although I know the basics of wiring didn't know about the regs for drilling holes. Friend building his own house soon so this will help big time
Hi hope u can help. If the beam goes fall width of house but is a supporting wall do u measure width of room or fall span of joist thanx
What country is this ? didn’t learn this in Australia so guess its not an issue
Drill in the middle and don’t drill to close to the edge sounds fine to me
This is for pipes too. Well done
Great stuff. I was just thinking today what the issues are with drilling additional holes in the floor joists to run new/replacement cabling. Nb: In the building industry all lengths (On a housing site for definite) are stated in mm. cm and meters just confuses things. Nnb: Generally pref to drill as high as possible on the floor joist to conserve room height below (Building regs) if you have exposed beams and will infill them to hide the cabling.
Excellent v log thanks
How would this change with a load bearing wall underneath the span?
Thank you for a very clear and concise explanation.
Great videos. How does it work if the room you are in in this example was is split into two. I'm assuming it just means that the cables have to be run on the outer side of the room where the joists meet the wall? Also if you're coming length ways against the joist do the cables need to be fixed onto the joist or can they sit in the void this would be for an existing site with ceilings
would be helpful to have a reference to the specific portion of the IET reference that is discussed here.
That is ideal on first fix. Do'nt expect the electrician to rip off all the ceiling to stick with that theory.
Hi I read that holes must be three times their diameter apart. Would this mean if a plumber has drilled a 28 mill hole for pipe then my hole for wires would have to be at least 84 mill away from it thanx
Hi thanks for your excellent video. If the loft space was not going to be ever boarded over do the regs allow for the cables to be clipped directly on top of the ceiling joists?
Best Regards Chris
Hi. Try and avoid placing cable on the top of joists in lofts as people can stand on them when accessing the roof space. Best to route the cables along the apex between the roof line and the joists in the roof as no one stand in the area. Thanks for commenting and watching. Gaz 👍
@@GSHElectrical Thanks Gaz for your quick reply much appreciated!
If you were talking to any other trade, or profession, what you are calling the 'Width' of the joist, would be referred to as the 'Depth' . Confusion might ensue especially if you were having discussion with structural engineer.
Didn’t want to say, but yep, correct..
I’m a spark and I would say depth too
Good video. Thanks. You'll often see cables strung from joist to joist through holes, with no support between the joists. Most cables need support every 250-300mm (on-site guide) and yet joists are typically 450mm apart. Should we be doing something to support the cables in between?
Hi great question. Appendix D page 141 On-Site Guide the title of table D1 is spacing of supports for cables in accessible position... I would class cables through joists in floors or ceilings as not accessible. Thanks for watching and commenting GSH Electrical 👍
what is 0.25 amd 0.4 that you multiply?
It’s in the on-site guide page I showed in the video 👍
Can you do both sides of the joist like that or just pick one? Does the load bearing joist count as a support, would it still be the entire length or just to that support?
Hi. I hope this helps 👍
www.elecsa.co.uk/Documents/Contractor-Documents/Pocket-Guides/Pocket-Guide-20.aspx
Thanks for commenting and watching GSH Electrical
verry good video
Really good video!!
Great video.
Would this be affected by what the joist was supporting? For example a truss system?
Also, would the same apply to every consecutive joist as I think I will need to drill through 8-10 for the cable run
Great video
Hi, where is the safe zone on the ceiling to drill the holes for downlights( this is in a flat without joists? )And can the cables run flat or resting in the ceiling using twin and earth cables without trunking ? Thanks
Great video - moved out of domestic sometime ago now management and about to wire my new extension very helpful, can you do a video on zoning in kitchens lol
Thanks for the kind comment this video applies for cable zones th-cam.com/video/LBf9dlI5JAg/w-d-xo.html
All the best and thanks again for watching GSH Electrical 👍
Depth not width.
Good job he is an electrician, and not doing an important job
Don't forget to teach your students to swear when the joists are so close together your drill won't fit.
Use a right angle drill
Or notch them over the top. ...
Kidding....
Centre of holes 4 X diameter of hole apart, and only a quarter of thickness of joist, in the 25-40% region and the 60-75% region of length. Interesting, not likely to need it ever, but I like to know rules, helps me be more of an intelligent client.
Maybe that's a really useful topic to cover on one of your channels, as you may be professionally focused, but I'd bet you have a fair number of consumers watching too and it would help good sparks and help customers find them as until recently I really struggled.
I have noticed that you always refer to the joist as the width but in the on site guide its the depth that used into calculations?
Apologies GSH Electrical. Thanks for watching
Really appreciate these great videos, what is your take on the domestic installer courses which are held over a period of about a month, which provides enough knowledge and skill to work in the domestic sector not commercial, they claim once these courses are passed a person may register onto a scheme, are these suitable for a person who simply wants to work in just the domestic sector?
Many thanks
Hi. All I will say on the domestic installer course is it take my learners 2 years to get it and a minimum of 3 6 hours site visits 👍 plus a portfolio 🤔. My learners earn it thanks... for the question Gaz
Why would we multiply it by 0.25 and 0.4? I understand how to do it, but not why we do it
It gives you the section where compressive & tensile forces are less. Somehow they've worked out that it's always from a quarter of the way in to almost halfway across the joist.
@@lmarkey1748 thank you!
Is there an Aico smoke alarm with no battery in it in the background?? PEEP PEEP
On a existing stud wall if a customer wants a dry line socket how do you drop the cable down with the top of the stud wall having no gap
Hi. You would have to drill a hole in the top of the wood or metal frame and then support the cables down to the socket outlet. Thanks GSH Electrical
10cm is hardly a joist. I would never spec that, even just for an attic ceiling.
Hi am I correct in thinking that after drilling in the prescribed zone you are permitted to bend and clip cable in order to place a socket on a wall. And that the holes ate for placing long runs of cables.
Hi. Then follow the prescribed zones laid out by BS 7671 thanks for watching GSH Electrical
Check out Metwood Joist Reinforcers www.metwood.com
They allow up to 4" holes in 2x8s, 6" holes in 2x10s and 2x12s
1 hole per joist only allowed.
They are engineered and or code approved.
I’m gonna drill in the middle :) Don’t laugh. I just moved in this house and the holes are on the edge. That’s when the previous owner decided to secure the cables. There’s quite a few dangling under the joists in the crawl space.
Great video but I wish your hand wasn't in the way of what you were writing.
Sorry 🤦🏻♂️
need to wear an external mic sound was kinda very low
Hi. Sorry production quality has improved in our later videos 👍. Thanks for commenting and watching Gaz.
@@GSHElectrical all good just the differences between different videos on youtube some come across as loud others like yours lower but mostly due to im guessing the distance from your camera cheers
Please stand on it . as if your walking around in the loft
I'm a structural engineer in alaska. this practice needs to stop, we've had quite a few roof failures and having some electrician hacking your trusses with sawsall to route cable is out of control
Real tradesmen use mm
Where did the IET get the idea of a zone to drill in? There appears to be no good structural reasoning behind it. From a structural point of view, you just need to avoid the lower section of joists, which resist the bending force from superimposed and dead loadings.
Hi. I don’t make the rules but often trades drill holes anywhere they need them causing potential issues over time... thanks for watching GSH Electrical
Seems a bit dangerous to turn joists into swiss cheese like this, I would be concerned about one 25mm hole in a joist that small let alone multiple holes in sucession!
Hi. I understand what your saying but the information in the video conforms with BS7671 and is required by my learners. Thanks for watching and commenting all the best GSH Electrical
This comes ultimately from the building regs and the specifications take this sort of thing into account. In that sense the joists size per span are over-engineered.
Ever seen a castellated steel beam? Think if it as similar to that. The amount of steel is the same but the span can be longer compared to a standard RSJ of solid steel. The height is increased and it has holes but is stronger. How come...?
@@GSHElectrical so basically do what the IET says and ignore structural loading calcs, timber integrity, or common sense? Good advice thanks for the clarification.
300 x 0.25, on a calculator? Oh dear
😂😂😂
In English please.....what the hell is a centimeter ,&millimeter????lol!!!!
Really? 🤔
Lol...
Learn the metric system. If you are in a country that doesn't use the metric system then these regulations don't apply to you anyway.