Notches or Holes, clip or not to clip?

[FatAlan]

Appart from the building regs specification on the size and positioning of notches and holes in joists is there a best practice on what to use? Is it just the case that notches are used in place of holes due to the cable positioning being outside that prescribed for holes. Are there any issues with not clipping cables under floor boards? I say this as when for instance you install down lights it seems prudent to have a fair bit of slack left for future work / fittings etc.

 

[J.C.E]

more effort to notch then it is drill a hole
if the hole is drilled in correct place- less likely to have a screw/nail go through it than if it was in a notch (unless you ues a metal plate)

always try get a few clips in under the floorboards to keep it off the plasterboard and alway from any screws etc- but impossible to clip in on its full run if its a rewire to an exisitng house and you only needed to take up a few boards- otherwise you will end up taking up all the poxy floorboards in the house!

 

[Pete999]

Appart from the building regs specification on the size and positioning of notches and holes in joists is there a best practice on what to use? Is it just the case that notches are used in place of holes due to the cable positioning being outside that prescribed for holes. Are there any issues with not clipping cables under floor boards? I say this as when for instance you install down lights it seems prudent to have a fair bit of slack left for future work / fittings etc.

My own personal view would be, if you come across an instance where by the joist have been notched by another, and drilling holes would/could possibly weaken the joists further, I have done in the past used these notches, I know it's not as the Regs say it should be done, but are the Regs not written for an ideal situation? I believe they are, (tin hat on, as well as flak jacket, and Chobam armouring)
Don't want to sound condescending but if you are fishing cables in a rewire say, you are hardly going to take floor boards up just to bang a few cable clips in are you? new build would be different but as you say it's normal to leave some slack for alterations. maintenance etc. If notches are used the I always clip the cables in the notch and cover the notches with a metal strip, just as extra protection.

 

[Squid]

more effort to notch then it is drill a hole
if the hole is drilled in correct place- less likely to have a screw/nail go through it than if it was in a notch (unless you ues a metal plate)

always try get a few clips in under the floorboards to keep it off the plasterboard and alway from any screws etc- but impossible to clip in on its full run if its a rewire to an exisitng house and you only needed to take up a few boards- otherwise you will end up taking up all the poxy floorboards in the house!

A notch is quicker, skill saw chisel bobs your uncle.

 

[ruston]

As @Pete999 , if a metal plate is fitted it is fine. If a joist has been notched it will quite apparent the floorboard has been up and it would take some kind of numpty to bang nails in without careful investigation

 

[Pete E]

On new builds, I am surprised that there is no requirement to clearly mark the floor boards to show cable and pipe runs...

In the past,I've seen it done for short sections of such runs through door ways ect, but I think that was down to the owner rather than the contractors/builders..

 

[Pete999]

On new builds, I am surprised that there is no requirement to clearly mark the floor boards to show cable and pipe runs...

In the past,I've seen it done for short sections of such runs through door ways ect, but I think that was down to the owner rather than the contractors/builders..

The way new builds are thrown up these days, I seriously doubt that there is time to mark where pipes and cables are, that is unless it's specified and paid for, stuff is thrown in, get paid and Foxtrot Oscar on to the next job, "not my fault if some Muppet nails or screw through a Pipe or cable, is it Boss?" Not much pride taken in the majority of new builds these days, and that includes some, not all, so called Electricians I'm afraid, how many new builds are wired using Mates and Apprentices, without any supervision.

 

[Squid]

On new builds, I am surprised that there is no requirement to clearly mark the floor boards to show cable and pipe runs...

In the past,I've seen it done for short sections of such runs through door ways ect, but I think that was down to the owner rather than the contractors/builders..

On new builds the joists are flimsy, most older houses notch in the middle nails to either edge of the board.

 

[ruston]

On new builds the joists are flimsy, most older houses notch in the middle nails to either edge of the board.

The houses are flimsy. The lofts look like a burst box of matches.

 

[Squid]

The houses are flimsy. The lofts look like a burst box of matches.

With 2x2 for joists and no room to stand in..........

 

[Pete E]

When I was in Germany in the 90's I came across a few of the more modern houses that had concrete for the upstairs floors and stairs and was told it was to do with their fire regs..

I'm not sure how wide spread that is over there, but their design and construction industry seems much more advanced than ours...As Pete999 says most of our new builds are built to the absolute lowest standards that the developer can get away with...

 

[Squid]

When I was in Germany in the 90's I came across a few of the more modern houses that had concrete for the upstairs floors and stairs and was told it was to do with their fire regs..

I'm not sure how wide spread that is over there, but their design and construction industry seems much more advanced than ours...As Pete999 says most of our new builds are built to the absolute lowest standards that the developer can get away with...

Lots of new building technology and tools are imported in from Germany, look at Festool, Hafelle the way buildings are insulated etc the UK sold its industries off in the past when we where world leaders what we now have ended up is Barratt Houses which are the cheapest of the cheap crapiest stuff around to fill a void and to make money.

 

[Pete E]

Sad but true...

 

[DPG]

Don't forget 'proper' notch cover plates are available, eg: 52mm x 73mm Safeplate - Protect Pipes & Cables - https://www.tlc-direct.co.uk/Products/TLSP1.html?source=adwords&ad_position=1o1&ad_id=45425533757&placement=&kw=&network=g&matchtype=&ad_type=pla&product_id=TLSP1&product_partition_id=174047055187&test=finalurl_v2&gclid=EAIaIQobChMI_b6gu5Hu2AIVUrbACh20nwzMEAQYASABEgIrD_D_BwE

 

[J.C.E]

A notch is quicker, skill saw chisel bobs your uncle.

telling me you can notch one joist quicker than you can drill 1 hole!?
you not got power tools!

 

[Squid]

telling me you can notch one joist quicker than you can drill 1 hole!?
you not got power tools!

Yep, find a drill and a bit to fit in between the joist so you can drill a level hole or just run a skill saw across the top twice. i know whats quicker especially through 100 year old wood.

 

[Deleted member 9648]

deleted

 

[PEG]

I know what is standard,and what's been done,is done,but nothing degrades a joists integrity,like a notch.
You can rectify 20 rogue holes,with some glue and a piece of hardwood dowel.

If you are lifting boards,i would recommend drilling,every time.

You can fish,and drill from different directions,to save lifting every board,which you will have to do,to notch.

I have a black and white information film,from the 50's,where they are "electrifying lighting" of some of the old terraced properties,in Trafford Park,after the war.

The sparks all have roofer's hatchets,to open ceilings,and notch the bejesus out of all the virgin 8 be 4's downstairs

 

[Leesparkykent]

telling me you can notch one joist quicker than you can drill 1 hole!?
you not got power tools!

He must be on that polish 95% gear he posted a link to if he thinks notching is quicker than drilling ... Did I read a post that you have the Milwaukee hole hawg?

 

[J.C.E]

He must be on that polish 95% gear he posted a link to if he thinks notching is quicker than drilling ... Did I read a post that you have the Milwaukee hole hawg?

best purchase of 2017 Lee hands down! flys through old and new joists no pressure- i heard good things about the Milwaukee self drive bits- but they get filled up of wood chippings after 2 or 3 joist and you have to clear it out- but with a flat blue bosch bit...laughing!

 

[Squid]

He must be on that polish 95% gear he posted a link to if he thinks notching is quicker than drilling ... Did I read a post that you have the Milwaukee hole hawg?

Thought you where a sparks not a plumber. You need some of my gear lol.

 

[ipf]

He must be on that polish 95% gear he posted a link to if he thinks notching is quicker than drilling ... Did I read a post that you have the Milwaukee hole hawg?

Is that another name for a brace and bit?

 

[willy fixit]

Deleted as I had not noticed the other appropriately derogatory comments regarding SWDs plumbing past

 

[PEG]

I did have a plumber (old school) show me how he got 15mm copper,across joists,through drilled holes. He did have to drill two supplementary holes,and stick a hardwood fid,in each end...but he used the method regularly...worked it out?

He reckoned since slip conduit wasn't needed,with t&e,sparks had it easy

 

[ferg]

Straight through the external walls

 

[PEG]

Straight through the external walls

Not a bad guess,but would be troublesome,regarding access to solder,and frost proofing...

 

[Squid]

I did have a plumber (old school) show me how he got 15mm copper,across joists,through drilled holes. He did have to drill two supplementary holes,and stick a hardwood fid,in each end...but he used the method regularly...worked it out?

He reckoned since slip conduit wasn't needed,with t&e,sparks had it easy

Hammered the pipe flat and cut notches...........

 

[chris murphy]

Don't forget 'proper' notch cover plates are available, eg: 52mm x 73mm Safeplate - Protect Pipes & Cables - https://www.tlc-direct.co.uk/Products/TLSP1.html?source=adwords&ad_position=1o1&ad_id=45425533757&placement=&kw=&network=g&matchtype=&ad_type=pla&product_id=TLSP1&product_partition_id=174047055187&test=finalurl_v2&gclid=EAIaIQobChMI_b6gu5Hu2AIVUrbACh20nwzMEAQYASABEgIrD_D_BwE

Hello DPG,

As I am sure that You / We all know - when these plates are used you have to notch the size and thickness of the plate out of the joist to fit them flat with the top of the joist.

Otherwise they would hold the Floorboards up from the joist and this would cause creaking floorboards as they loosen the nails / screws after a period of time being walked over.

Because the plates are thick enough to resist penetration by a nail they are thick enough to cause a problem with laying the Floorboards unless they are notched into the joists.

Even with some new builds where Flooring Grade Chipboard seems to be the favourite specification for Flooring these plates could still cause a problem.

They are not fitted as the picture shows on the webpage - which is just `nailed` in position on the top of the joist.

I mention this for possible future readers of this thread who are not Electricians, Heating / Gas Engineers or Plumbers.

Regards,

Chris

 

[Toneyz]

The houses are flimsy. The lofts look like a burst box of matches.

I remember doing new houses at a site and another housebuilder on the other side of the road fitting mock fiberglass chimneys to the houses couldn't believe what I was seeing.

 

[Toneyz]

On new builds, I am surprised that there is no requirement to clearly mark the floor boards to show cable and pipe runs...

In the past,I've seen it done for short sections of such runs through door ways ect, but I think that was down to the owner rather than the contractors/builders..

In the past when new houses had traditional joists rather than the TJI joists of today the plumber's pipes were notched into the top of the joists chippy then put chipboard floor sheets down and always from my experience they marked the floor where the pipes were saved them nailing them and us drilling them from above. I used to mark the floor each side of a stud and walls where the cables ran as so chippy did not nail when putting on skirting.

 

[johnduffell]

As @Pete999 , if a metal plate is fitted it is fine. If a joist has been notched it will quite apparent the floorboard has been up and it would take some kind of numpty to bang nails in without careful investigation

I gave you an "optimistic" there - if you ask around it doesn't take long to find a stack of weekend DIYers who have needed to fix a loose floorboard and not wondered why there was a screw missing Not sure numpty is the word I'd use, maybe just inexperienced and possibly being hassled to do a job they've not encountered before!
https://www.google.co.uk/search?q=nail+through+pipe+floorboard

 

[FatAlan]

Bought a few of these but as stated above they will need insetting themselves to enable the floorboards to fit back flush.

 

[EbolaSideRoom]

Yep, find a drill and a bit to fit in between the joist so you can drill a level hole or just run a skill saw across the top twice. i know whats quicker especially through 100 year old wood.

Respectfully, you’re buying the wrong tools....https://www.milwaukeetool.com/power-tools/cordless/2707-22

 

[GB.Kayak]

more effort to notch then it is drill a hole
if the hole is drilled in correct place- less likely to have a screw/nail go through it than if it was in a notch (unless you ues a metal plate)

always try get a few clips in under the floorboards to keep it off the plasterboard and alway from any screws etc- but impossible to clip in on its full run if its a rewire to an exisitng house and you only needed to take up a few boards- otherwise you will end up taking up all the poxy floorboards in the house!

Sometimes it is more effort to drill a hole ... in Victorian properties in Scotland ... not sure whether it goes further afield ... there was a practice of installing 'deafening' or 'deadening'. Strips of wood are nailed to the joists at approximately mid height and thin boards are laid between the joists with their ends resting on the strips at each side. The boards are then covered with a very 'rough' lime mortar. I believe the purpose of this practice was to reduce noise transfer. It makes the drilling of holes at mid joist height a much more involved process when this material needs to be cleared away before piercing the joists.

 

[JK-Electrical]

The way new builds are thrown up these days, I seriously doubt that there is time to mark where pipes and cables are, that is unless it's specified and paid for, stuff is thrown in, get paid and Foxtrot Oscar on to the next job, "not my fault if some Muppet nails or screw through a Pipe or cable, is it Boss?" Not much pride taken in the majority of new builds these days, and that includes some, not all, so called Electricians I'm afraid, how many new builds are wired using Mates and Apprentices, without any supervision.

I agree. I did an EICR on a 10 year-old property last week and discovered that one of the live conductors of the RFC supplying the lower-level sockets of the property had been connected to the MCB for the RFC supplying the upper-level sockets of the property and vice-versa. How this error wasn't detected during the initial end-to-end tests on both circuits beats me.

 

[GB.Kayak]

I agree. I did an EICR on a 10 year-old property last week and discovered that one of the live conductors of the RFC supplying the lower-level sockets of the property had been connected to the MCB for the RFC supplying the upper-level sockets of the property and vice-versa. How this error wasn't detected during the initial end-to-end tests on both circuits beats me.

When I 'checked out' the electrical system in the property that I am in at the moment, I discovered that one of the socket circuits was connected to 2 separate MCBs! It took a while to trace down why the circuit appeared to be permanently 'on' whichever MCB I switched off.

 

[JK-Electrical]

When I 'checked out' the electrical system in the property that I am in at the moment, I discovered that one of the socket circuits was connected to 2 separate MCBs! It took a while to trace down why the circuit appeared to be permanently 'on' whichever MCB I switched off.

As I've encountered this very same issue several times in the past, I realised straight away that there was a cross-connection between the two RFCs. This was confirmed by switching both MCBs off then doing end-to-end tests on both circuits.

 

[chris murphy]

Sometimes it is more effort to drill a hole ... in Victorian properties in Scotland ... not sure whether it goes further afield ... there was a practice of installing 'deafening' or 'deadening'. Strips of wood are nailed to the joists at approximately mid height and thin boards are laid between the joists with their ends resting on the strips at each side. The boards are then covered with a very 'rough' lime mortar. I believe the purpose of this practice was to reduce noise transfer. It makes the drilling of holes at mid joist height a much more involved process when this material needs to be cleared away before piercing the joists.

Hello GB.Kayak,

I found out about `Deafening` about 27 years ago when my Business partner and I went up to Edinburgh to carry out installation of a very large `Domestic` Heating system containing approximately 50 Radiators - build the Boiler from parts in the Basement - a complete re-plumb including 6 Bathrooms and 4 x 450 litre Hot Water Cylinders in a very large House that had been bought by a very good Friend of ours.

Although it was just a Big Family Home there was nothing `Domestic` about the Heating or Plumbing in that House !

I had previously visited Edinburgh / the House and spent a Week measuring up and making notes, sketches and taking photographs and some videos to get enough information to design the Heating and Plumbing systems and place Material Orders when I went back Home.

Because the Floorboards were `irreplaceable` - 12" wide x 1" thick highly polished Oak it had been agreed that although We were `good at taking up Floorboards` - a `Joiner` / Furniture Quality Carpenter was going to be engaged to take up all the Boards that we would require and on my `Survey visit` I identified most of the pipe runs and sections of Floorboards that we needed lifting.

I describe the above about the Floorboards because it meant that I had never been able to lift a Board during the Week that I was at the House - all I `knew` was that there should be plenty of room under the Floors as some of the Joists were 15" on the Ground and First Floors and were 12" on the Second Floor.

From my brief description of the Heating & Plumbing systems You might be able to imagine the `Hundreds of Metres` of Copper pipe to be installed.

Can You imagine my `Shock` when we arrived to start work on Day 1 and found the `Deafening` that You described under every Floorboard / between every Joist - level with the top of every Joist !

We then had to create Pipe runs through the `Deafening` - although we had Labourers on the job and we found that channels could be `grooved` through the material using wood battening and a hammer the `Deafening` added a lot of money to the Labour of the job.

We also needed a lot more Floorboards taken up by the `Furniture Maker Carpenter` to enable these channels to be created.

As We were doing the work / working away from Home as a favour for our good Friend we did not lose any money on the job - although we were working on `Mates Rates` and staying at his Family`s Home - He paid for the Labourers to create our Pipe channels.

However if we were working on a Quote basis for a Client / Building Contractor we would have had a large wage bill for extra Labour to create the pipework channels in the `Deafening`.

That was the biggest `surprise` that I have ever had on any Job and it was a very Big Job regarding the pipework runs !

Sorry that this message became so Long winded.

Regards,

Chris

 

[Generator]

What's all this about 'notching'? - I thought cables had to be at least 5omm from the top or bottom of a joist? - that makes an awfully deep notch! - probably seriously weakens the joists. Isn't that why cables are passed through drilled holes? Pipes are ok - you just get wet!
If you cover a cable with a metal plate it should also be earthed, at the same rating as the circuit CPC. Better to drill holes - use a right angle drill. I bet a good 'numpty' could drive a nail through a protection plate - if it bends he could drill it for a woodscrew!

 

[Pete999]

What's all this about 'notching'? - I thought cables had to be at least 5omm from the top or bottom of a joist? - that makes an awfully deep notch! - probably seriously weakens the joists. Isn't that why cables are passed through drilled holes? Pipes are ok - you just get wet!
If you cover a cable with a metal plate it should also be earthed, at the same rating as the circuit CPC. Better to drill holes - use a right angle drill. I bet a good 'numpty' could drive a nail through a protection plate - if it bends he could drill it for a woodscrew!

You mean bonded surely? self tappers would be best if you are fixing to the cover plate.

 

[Cadgey123]

Don't forget 'proper' notch cover plates are available, eg: 52mm x 73mm Safeplate - Protect Pipes & Cables - https://www.tlc-direct.co.uk/Products/TLSP1.html?source=adwords&ad_position=1o1&ad_id=45425533757&placement=&kw=&network=g&matchtype=&ad_type=pla&product_id=TLSP1&product_partition_id=174047055187&test=finalurl_v2&gclid=EAIaIQobChMI_b6gu5Hu2AIVUrbACh20nwzMEAQYASABEgIrD_D_BwE

Wow thanks for this link. This has changed my life.......

I used to use Metal UV box lids

 

[telectrix]

in answer to posts#39 and #40.

the plates should not be earthed as they are not exposed conductive parts of the installation. they are just metal plates with cables sitting on them.

nor should the y be bonded, pete, as they are not extraneous.

 

[Pete999]

in answer to posts#39 and #40.

the plates should not be earthed as they are not exposed conductive parts of the installation. they are just metal plates with cables sitting on them.

nor should the y be bonded, pete, as they are not extraneous.

Tel, I was trying to be sarcastic, obviously didn't work, did it? I agree with what you are saying. Just trying to point out what a ridiculous statement it was in the first place, next you will have to earth the screws and nails that are used to fix the floorboards, stupidity at it's best, earth the plates my arse.

 

[DPG]

Generator - do you also earth (bond) radiators and metal windows????

 

[telectrix]

and don't forget sink tops and metal garage doors

 

[Squid]

and bond all the floorboard nails.........

 

[Generator]

I'll ignore the sarcasm Pete (seen far worse on here! ). I was thinking about the similarity to metal capping, which I think is now supposed to be earthed ( certainly in 522.6.6 outside of a 'zone' ). Earthing of concealed metallic cable covering is only common sense in a house - regs or not. Everything has to be hidden - even sockets.

I've had experience of this in my existing house AND the previous one! I got a good belt when I touched the end of a wall capping under the floorboards - good job I didn't have the other hand on the CH pipes! Turned out the Dado Rail in the room below was nailed exactly over the capped ring main cables, vertically above a socket! - I was wondering why that circuit had a lowish IR! - 5Mohm.
In the previous house the wall in the hall had a faint 'rough ' feeling in the area above a socket - that circuit also had a 'lowish' IR , guess what? - nail through the capping, fixing the Dado Rail!
In both cases the capping can remain live for years - and it wouldn't trip an RCD either. If the capping is earthed, a penetrating nail/screw/drill would trip an MCB if it touched a live, or at least an RCD (hopefully).

So, hence my comment about the protection plate - which wouldn't be required if the joist were to be drilled! - and no, I wouldn't earth radiators (which are connected to earthed pipework), nails, screws,
or metallic windows ( unless they are motorised).

Better keep my head down now!
John.

 

[Generator]

I'll ignore the sarcasm Pete (seen far worse on here! ). I was thinking about the similarity to metal capping, which I think is now supposed to be earthed ( certainly in 522.6.6 outside of a 'zone' ). Earthing of concealed metallic cable covering is only common sense in a house - regs or not. Everything has to be hidden - even sockets.

I've had experience of this in my existing house AND the previous one! I got a good belt when I touched the end of a wall capping under the floorboards - good job I didn't have the other hand on the CH pipes! Turned out the Dado Rail in the room below was nailed exactly over the capped ring main cables, vertically above a socket! - I was wondering why that circuit had a lowish IR! - 5Mohm.
In the previous house the wall in the hall had a faint 'rough ' feeling in the area above a socket - that circuit also had a 'lowish' IR , guess what? - nail through the capping, fixing the Dado Rail!
In both cases the capping can remain live for years - and it wouldn't trip an RCD either. If the capping is earthed, a penetrating nail/screw/drill would trip an MCB if it touched a live, or at least an RCD (hopefully).

So, hence my comment about the protection plate - which wouldn't be required if the joist were to be drilled! - and no, I wouldn't earth radiators (which are connected to earthed pipework), nails, screws,
or metallic windows ( unless they are motorised).

Better keep my head down now!
John.

 

[pirate]

I have bonding to my cutlery drawer, so none of my forks are risky when i chuck them in randomly...but, I'm puzzled about diversity...does the number of adjoining knives and spoons affect the situation were I to accidentally switch the whole drawer on at once, given the lighting in said drawer is tee'd off the cooker-hood...and the drawer slides are only on a 6mm cpc?

 

[pirate]

and on a serious note, in my last house I removed an old carpet in a bedroom and saw a slightly raised nail-head...it was live... and had been for years probably...neatly placed into a cable supplying the nearest socket...it was my daughters bedroom, and she was 1 at the time, crawling around on all-fours..
naturally, not being a spark, I put a thicker carpet down!