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]

Odd, all of the concrete lintels used where I served my apprenticeship had steel rebar in them (domestic/small commercial building company)

Catnic is a company which has become a generic term for any steel box section lintel.

 

[Knobhead]

Commercially made concrete lintels will have stressed rebar embedded. The trouble with saying its OK to drill the lintel is where does it stop being a lintel and become a beam.

The only safe answer is DO NOT DRILL!

I’m not going in to the stresses involved in a beam other the to say they’re not call “pre-stressed” for nothing.

 

[PEG]

I would be very dubious of the quality of a concrete lintel with no wire or re-bar...its' failure would be less than gradual :icon12: and if drilling Catnics and Batnics is a no-no,an urgent e-mail needs to be sent to every curtain/blind fitter round my way :conehead:

 

[telectrix]

only way i can see is to drill through below the top of the door frame, below the lintel.

 

[Geordie Spark]

Here ...... THIS is what you need:

Thermal lance is every bit as awesome as it sounds | MAKE


And I once made one just like this which was used on a bank vault (legitimately as it happens)

 

[Knobhead]

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.

With a thermic lance it will even fuse the concrete and steel in to homogenous channel as you burn through. Not really practical though, that porch wouldn’t be there for long, as for the decorating afterwards……..


Beat me to it Geordie.

I have used one for cutting though cast iron.

 

[Geordie Spark]

With a thermic lance it will even fuse the concrete and steel in to homogenous channel as you burn through. Not really practical though, that porch wouldn’t be there for long, as for the decorating afterwards……..


Beat me to it Geordie.

I have used one for cutting though cast iron.

Well it was 1974 when I was working at a company that specialised in diamond cutting & drilling of concrete and I was there to make & develop the machinery.

They got a job chopping a lump out of a bank vault in Newcastle and for some reason unknown to me it was decided to use this thermic lance thing and I got th job of making it.

I remember there was a rack of 10 or 12 oxygen cylinders all connected together by a manifold which I made and I was there to witness it being tested out in the yard.

The test was to cut in half a four foot square cube of reinforced concrete which had been cut out of a Dry Dock of one of the Tyne's shipyards a couple of weeks before and had ended-up back at our works yard because somebody thought it would come in handy.

I remember the test was very successful but made a hell of a noise and lots of smoke - it was a bit like being on a battlefield. God knows what it must have been like using it in the confined space of the bank vault!!

 

[Knobhead]

When you see one in action they’re disappointing. Just like a kids sparkler, until you see what they can do. Refractory concrete, pah, no problem. Try burning cast iron with oxy-propane, you may as well use a teaspoon, lay that pretty sparkler on it and it’s like cutting butter.

We used oxygen in the process, this is the tank. There were tap off points around the plant for thermics to be used.

 

[Guest111]

Just for anyone interested,in prestressed concrete the wires are laid in the mould and sick out at each end,these are then clamped to hydraulic rams and effectively stretched,when this is done the concrete is poured into the mould and allowed to set,once set the rams are released and the wires shrink back slightly pulling the concrete with them so it is held in a state of compression.

 

[Guest55]

in tommorrows show , phil will explain how to make jelly with fruit suspended in it.

;-)

 

[Guest111]

in tommorrows show , phil will explain how to make jelly with fruit suspended in it.

;-)

easy that one,make sure the fruit is well drained and add it to the jelly about 15 minutes after pouring,otherwise the fruit will settle to the bottom.lol

 

[Guest55]

you've just spoiled tmorras show you halfwit !

;-)

 

[polo1]

I'm surprised ( and not a little disappointed) that no one has consulted me about drilling through lintels, after all I became a bit of an expert (with help from many on here) on the dynamics and techniques for getting a stuck drill bit removed from one
However HHD, why go high level for an external socket?; why not drop down internally, then out through the wall, avoiding the whole lintel question.....simples!

 

[VoltzElectrical]

good advice there polo methinks

 

[HappyHippyDad]

I'm surprised ( and not a little disappointed) that no one has consulted me about drilling through lintels, after all I became a bit of an expert (with help from many on here) on the dynamics and techniques for getting a stuck drill bit removed from one
However HHD, why go high level for an external socket?; why not drop down internally, then out through the wall, avoiding the whole lintel question.....simples!

Ah yes I remember that one Polo :smile5:, still there as a coat hanger is it?

My first suggestion to them was to have it in another place, equally as accessible but they wanted it exactly as stated!!

The door is flush with the wall so no room to drill through the wall on the required side!!

Floorboards up will be fine :smile5:

 

[edexlab]

I'm not an expert or a structural engineer but I used to build prestressed concrete moulds for a company mostly for T beams, but also for larger structures, like bridge spans and sculptures.

The tension in the wires is released, when the concrete is set and compressive force allows long concrete components to be made, and any tension on the object is taken up by the steel wire exactly as Phild described,

Each wire had @1 1/2 to 3 tonnes of pressure upon them depending on the design and at the ends would be a steel plate 3-8 inches thick through which the wires passed, the previous designs would flex under the strain of having 50 + wires through them and one of the first tasks was redesign the structure at the ends to stop the bending effect as it made the castings at each end curved and unusable, which meant they had to be cut off and binned, it was actually easy to prevent with a bit of common sense but the few rival firms building these moulds just accepted the bending/flexing as part of the process.

As for stories of concrete shattering like glass, I was told by the manufacturers engineers that this is due to defects in the concrete , not the tensioned wire releasing energy when damaged and an extremely rare event

If it was a common occurrence then they wouldn't be able to use it for long structures such as bridges, tall buildings etc as the constant flexing would destroy the structure very quickly

I saw it happen plenty of times at the site though, when the wire clamp arrangements were worn and released the wire before the concrete had gone off fully, creating a whiplash effect which the concrete couldn't absorb, causing a shattering effect, the wire stubs would fly away from the plate and pass straight through solid 8 inch concrete blocks leaving nice bullet like holes a couple of people had been injured quite badly by this in previous years leading them to place blocks and sandbags to receive any broken wire stubs.

 

[ayjay]

modern houses have steel lintels older ones concrete
the steel rods within old concrete housing lintals isn,t pre-tensioned-
as long as a hole is drilled thro and misses the steel no prob
use an sds drill
dunno why u need to drill a hole thro a lintel tho

 

[Geordie Spark]

modern houses have steel lintels older ones concrete
the steel rods within old concrete housing lintals isn,t pre-tensioned-
as long as a hole is drilled thro and misses the steel no prob
use an sds drill
dunno why u need to drill a hole thro a lintel tho

Ventilation.

 

[Guest77]

modern houses have steel lintels older ones concrete
the steel rods within old concrete housing lintals isn,t pre-tensioned-
as long as a hole is drilled thro and misses the steel no prob
use an sds drill
dunno why u need to drill a hole thro a lintel tho

Free English Korean Translation Online Dictionary Translator

 

[shanky887614]

drilling a steel rsj is easy with thd right bit.

i drilled some steel that an ahu was sat on before with dewalt extreme 2 bits and they went through like butter (dont push on too hard, if the bits get stuck they will snap trying to extract them

(dewalt bits have a small pilot bit)

 

[davesparks]

modern houses have steel lintels older ones concrete
the steel rods within old concrete housing lintals isn,t pre-tensioned-
as long as a hole is drilled thro and misses the steel no prob
use an sds drill
dunno why u need to drill a hole thro a lintel tho

Concrete lintels are still used in modern houses

 

[trev]

Concrete lintels are still used in modern houses

Obviously not in clown boy's world. I'd love to know how you're supposed to know exactly where the steel is though. X ray eyes, you reckon?

 

[shanky887614]

Obviously not in clown boy's world. I'd love to know how you're supposed to know exactly where the steel is though. X ray eyes, you reckon?

yes and no, concrete or metal are used depending on which is cheaper at the time

 

[trev]

concrete or metal are used depending on which is cheaper at the time

After 36 years in the trade I've got a fair idea of how it works cost wise mate

 

[trev]

Just so there's no doubt, I'm just jerking your chain there Shanky.