driling through a lintel?

[HappyHippyDad]

Evening all...



I have been asked to fit an outside socket just outside the front door (on the small bit of brickwork you can see in the first picture).

It is very close to the CU so no problems there, but I am am not sure about the route to the socket from the CU.

Not having a great deal of experience on site I have not been around many builders so am unsure of the construction of lintels and if they are possible to drill through.

My thoughts are:

If it's steel I wont be getting through it.
If it's concrete, it must be pretty strong concrete otherwise its not doing it's job as a lintel so again tough to get through.
Should I be drilling through a lintel in the first place?
How high is a standard lintel, could I drill above above it (below ceiling level)?


It actually sounds hollow when I tap the bit above the door from the inside, but thats just giving me false hope as there has to be a lintel there?

Outside is a hollow porch covering. The second picture shows this (although this is actually next door so the picture looks the wrong way around).

I'd appreciate any advice on what you guys would do to get that cable out there?

 

[davesparks]

Never drill through a concrete lintel, no if 's, no buts, just don't do it!

Never drill through any structural steel without the permission (written) of a structural engineer.

 

[Knobhead]

What’s your insurance like?

 

[Geordie Spark]

Don't quote me on this, but I think you can have a serious issue drilling through a concrete lintel and it's to do with the wire reinforcing being under tension (I think)

It's just something I remember my builder mate yapping about a while ago

Maybe some of our more learned colleagues can advise?

Edit:

there you go .... they beat me to it!!

 

[davesparks]

I would suggest popping up a floorboard above and drilling above the lintel.

 

[Andy78]

What’s your insurance like?

Never mind what they like, what about what they don't like ? I bet drilling through lintels is on their list somewhere.

 

[davesparks]

Don't quote me on this, but I think you can have a serious issue drilling through a concrete lintel and it's to do with the wire reinforcing being under tension (I think)

It's just something I remember my builder mate yapping about a while ago

Maybe some of our more learned colleagues can advise?

Yes, pre-stressed concrete can shatter as if it was a pane of glass if you hammer drill into it.

 

[uksparks]

HHD as much as I like you, just don't go drilling through them! I have been asked many times and it's always a firm NO!.... Unless you have a structural engineer to hand who wants to do it and take the blame!

 

[davesparks]

This is the sort of thing you should have learned on your apprenticeship, and one of the many many things that get missed out of 5 week idiot courses but could easily endanger peoples lives.

 

[Rockingit]

I vaguely seem to remember seeing / hearing somewhere that there's some engineering/stress/physics thing where if you just drill seven tiny holes in exactly the right pattern you can blow a big hole through any thickness of concrete.

 

[Geordie Spark]

I vaguely seem to remember seeing / hearing somewhere that there's some engineering/stress/physics thing where if you just drill seven tiny holes in exactly the right pattern you can blow a big hole through any thickness of concrete.

Hmmm .... I think I could have a job for you.

There's this bank up the road from me that wouldn't give me a loan and I was thinking .............:ihih:

 

[andyelectric]

If the house was an old victorian jobbie such as I am used to I would have thought you should easily be able to get above the lintel, however on these newbuild houses I'm not so sure. No-one has answered HHD as to whether he is likely to get above it?

 

[Rockingit]

Well, I'd have expected to find the bearers sat on top of that lintel so pull up a floor board and get your tape measure out!

 

[davesparks]

I vaguely seem to remember seeing / hearing somewhere that there's some engineering/stress/physics thing where if you just drill seven tiny holes in exactly the right pattern you can blow a big hole through any thickness of concrete.

Sod that, a 1KG ground maroon securely strapped to it will obliterate it,along with the eardrums of anyone daft enough to stand near it!

But thanks to some daft EU ruling you can put it in the post as a UN1.4S item thanks to it just being loose powder.


For those of you who don't play with fireworks for a living, a 1KG ground maroon is basically a kilogram of powdered aluminium in a plastic bottle with an electronic detonator poked through the lid.

And yes you can put this in the post legally thanks to a daft bit of EU legislation.



And yes I have put away more whiskey this evening that the government say I should consume in a month.

 

[Rockingit]

And yes I have put away more whiskey this evening that the government say I should consume in a month.

Good work, sir.

 

[robd]

Can you get floor up and get through to porch level and fish it through there?

 

[davesparks]

Looking at that fuseboard and the plywood plywood porch I'd date it in the eighties,so either a prestressed concrete lintel or a catnic type steel box lintel.

Either way pop a floorboard above and you'll probably find the hole they drilled to feed that R80 downlight .

 

[Marvo]

**looks for tin hat** I guess I'm in the minority if I say that many lintels are basically installed as shuttering and are only structural whilst the brickwork above them is curing. If there's 5 courses or more of bricks above them and no signs of cracking or other similar issues then I wouldn't have a problem with drilling a 10 or 15mm hole in one. They're usually about 15-20MPa concrete so any SDS drill should work and there probably won't be steel in the centre of the lintel but if you use a small pilot drill like 5mm it will probably deviate around the steel wires if you hit them.

I suppose the correct answer is to get the site engineer or builder to okay it.

 

[davesparks]

Good work, sir.

That is a matter of opinion!

In my opinion I agree

But in the opinion of this poor buggers who have to work with me tomorrow I doubt very much that it is 'good work'


Considering the stick I gave them today about the panto set which was originally built for a 1985/86 rendition of Aladdin I think I'll be getting sworn at tomorrow!

Can you believe FFE are still sending out a panto set built in 1985! It's older than me!

But at least it was built properly and the pin hinges actually line up! They even used proper slotted screws for them, and dovetail joints on the flats!
It just a shame the cloths have turned yellow and smell like the carpet in the dreaded house where a 90 year old bloke lived which you have to rewire.

 

[HappyHippyDad]

The lintel will be getting well and truly left alone!!

Many thanks to all the replies..

I shall have a rethink, floorboards coming up sounds like the best option so far I think.

 

[Rockingit]

That is a matter of opinion!

In my opinion I agree

But in the opinion of this poor buggers who have to work with me tomorrow I doubt very much that it is 'good work'


Considering the stick I gave them today about the panto set which was originally built for a 1985/86 rendition of Aladdin I think I'll be getting sworn at tomorrow!

Can you believe FFE are still sending out a panto set built in 1985! It's older than me!

But at least it was built properly and the pin hinges actually line up! They even used proper slotted screws for them, and dovetail joints on the flats!
It just a shame the cloths have turned yellow and smell like the carpet in the dreaded house where a 90 year old bloke lived which you have to rewire.

Reminds me of a Cinderella coach I once had the misfortune to tour! I had to allow a full hour on every in, simply for running repairs.

 

[davesparks]

**looks for tin hat** I guess I'm in the minority if I say that many lintels are basically installed as shuttering and are only structural whilst the brickwork above them is curing. If there's 5 courses or more of bricks above them and no signs of cracking or other similar issues then I wouldn't have a problem with drilling a 10 or 15mm hole in one. They're usually about 15-20MPa concrete so any SDS drill should work and there probably won't be steel in the centre of the lintel but if you use a small pilot drill like 5mm it will probably deviate around the steel wires if you hit them.

I suppose the correct answer is to get the site engineer or builder to okay it.

In the UK all concrete lintels will have at least 1 steel wire through it, and be pre-stressed via this steel wire.

Almost anything which pre-dates this will have wooden lintels.

And I pretty sure for the pics this is late 70s or early 80s construction so will be either prestressed concrete or a steel box catnic lintel.

 

[davesparks]

Reminds me of a Cinderella coach I once had the misfortune to tour! I had to allow a full hour on every in, simply for running repairs.

We had rindercella last year, bloody ponies shat on the stage ever night during the transformation! Thankfully I was on flys so didn't have to go near it

Was it a qudos panto by any chance?

 

[Marvo]

Most of our lintels are also the pre-stressed type with internal tensioned wires. I'm not familiar with the catnic type you mention though.

The prestessed lintels are rarely rated as structural, they're agressively supported in the middle during the build until the brickwork around then has properly cured because the sag under the weight if not. Once the mortar in the brickwork above has reached full strength the lintel should be all but redundant as far as structure goes.

 

[Rockingit]

In the UK all concrete lintels will have at least 1 steel wire through it, and be pre-stressed via this steel wire.

Almost anything which pre-dates this will have wooden lintels.

And I pretty sure for the pics this is late 70s or early 80s construction so will be either prestressed concrete or a steel box catnic lintel.

Not necessarily so. I cut to length two brand new concrete lintels at my house a couple of weeks ago and neither had rebar or any form of wire in them.