Burying Galvanised Steel Conduit

[bailes1992]

I was wondering if any of you have any experience burying galvanised steel conduit?

My current plan is to make up the conduit, T-Wash it and give it a couple of coats of primer and hammerite before I sink it in the ground but I'm wondering if it will be enough? My Father has suggested covering it in heat shrink before it is buried? Is it needed?

The conduit will be the only CPC to an outbuilding so it's essential it cannot corrode over time.

And yes, I could run an SWA but I don't want to.

Sam

 

[Pete999]

I'm not sure I can believe that it cannot be stopped rusting?

Surley if all threads are protected, the full length of the conduit is painted thoroughly and covered in PVC then it's going to last a long time? After all an SWA is just galvanised steel wires covered by a PVC sheath! Or even covered in denso tape which pipe fitters use to stop their non galvanised steel pipes from rusting!

Sorry Mate how on earth are you going to cover lengths of conduit in PVC, it's just not a practical option, OK in the world of theory, but totally impracticable.

 

[bailes1992]

So how do you plan to completely "seal" your conduit .....

In fact why are you just making this so complicated ....... it can't be about costs as SWA is much quicker to install, and when done properly will last for decades

unlike steel conduit

A couple of years ago I was swapping a panel heater in an out building - I did a Zs - which showed there was no earth .... a galv box, installed above ground was almost completely disintegrated ...

Installation time isn't an issue as I will be installing myself.

There's also the other issue of getting data out to the garage. I could run a seperate PVC tube underground for the data, but I would still run galv up the side of the house as PVC never looks as good as galv conduit in my opinion.

 

[Pete999]

Installation time isn't an issue as I will be installing myself.

There's also the other issue of getting data out to the garage. I could run a seperate PVC tube underground for the data, but I would still run galv up the side of the house as PVC never looks as good as galv conduit in my opinion.

I'm out

 

[Toneyz]

Well the O.P. has asked what the forum thinks and has a consensus answer that this is a bad idea.

 

[willy fixit]

I'm glad the PME/Equipotential zone issue has been clarified.

 

[snowhead]

Well the O.P. has asked what the forum thinks and has a consensus answer that this is a bad idea.

That won't stop him.

 

[Toneyz]

The run cannot be that long SWA can't cost that much.

 

[Pete999]

That won't stop him.

Good quals in building services, makes you wonder if all that studying was worth it.

 

[bailes1992]

The run cannot be that long SWA can't cost that much.

The run is approx 30 meters.
I will have to purchase either 30m of 10mm² 3c SWA and a consumer unit for the garage.
Or, 30m of 1.5mm² 3 Core for lighting, 30m 2.5mm² for heating and another 30m 4mm² for power.

Not a huge issue I admit, but if there was a way I could use the materials I have then I'd probably keep the few hundred quid in my pocket.

Shame I don't have any stainless conduit.

 

[bailes1992]

Good quals in building services, makes you wonder if all that studying was worth it.

Difference between having an idea and seeing if anyone else has experience in it than going right ahead and just doing it!

After all someone may have said they've buried a galv conduit wrapped in denso tape and it was fine 10 years later. In which case I'd probably give it a go myself.

 

[Strima]

The run is approx 30 meters.
I will have to purchase either 30m of 10mm² 3c SWA and a consumer unit for the garage.
Or, 30m of 1.5mm² 3 Core for lighting, 30m 2.5mm² for heating and another 30m 4mm² for power.

Not a huge issue I admit, but if there was a way I could use the materials I have then I'd probably keep the few hundred quid in my pocket.

Shame I don't have any stainless conduit.

What about voltage drop and maximum impedance for disconnection times?

Also derating factors for circuits run together.

SWA for the power and armoured CAT5/6/7 for the data. Much less to go wrong.

 

[westward10]

Just whack it in and be done with it as it is what you intend to do or is this just a carrot and stick thing.

 

[KEV 1 N]

Good luck pulling all those cables through 30 metres of conduit! Don't use washing up liquid as a lube, it contains salt, so will aid the inevitable corrosion of the conduit

 

[Toneyz]

Good luck pulling all those cables through 30 metres of conduit! Don't use washing up liquid as a lube, it contains salt, so will aid the inevitable corrosion of the conduit

30mtrs and two bends good luck

 

[Darkwood]

I am starting to assume the OP is ignoring all advice because they cannot terminate SWA or as is common that the conduit etc has already been purchased and damned doing there hardest to recoup any losses...

My advice is take the losses and prevent costs further down the line.