sealing a conduit.

[bigegg]

i want to run a swa cable under about 3m of concrete patio.
the trench is dug.
rather than just lay the cable in the trench and cover with concrete, i want to use some 40mm pvc pipe as ductwork.
it will mean having a "U"-shaped piece, with the verticals running up the wall of the house and garage.
both bends will be buried in concrete.

obviously, this means the pipe will eventually fill with water.

does it matter? can i ignore it?
should i drill drain holes? 10mm?
is silicone sealer going to be enough to seal around the cable where it enters the duct?

is there an "industry method" of dealing with this issue?

 

[CompoSimmonite]

For such a short run proper armored cable isn't going to cost too much.

 

[bigegg]

For such a short run proper armored cable isn't going to cost too much.

i'm using armoured. (SWA), just want to run it in a duct rather than surrounding in concrete.

 

[eLuSiVeMiTe]

https://www.drainageshop.co.uk/50mm...k4T6pX8_8HRW6R4x28iVgmiRutLtYk_IaAqFlEALw_wcB

Stick it in landdrain and don't worry.

 

[mtt.tr]

Swa is fine for direct burial will be fine in duct, just be wary it could become a rat run.

 

[jimbo84]

The SWA isn't going to come to any harm even if the ducting fills with water.

If you do want to seal it up they make rubber bungs to connect waste pipes to larger soil pipes, not sure if they do any smaller versions that would fit inside the ducting. Or solvent weld a large stuffing gland into the ducting.

 

[slim_boy_fat]

@bigegg If you're determined , non setting silicon is what I'd use.

 

[Mikes]

Expanding foam would be my solution as could be pushed into the pipe to give a nice deep seal. Easy to remove if the case ever arose.

 

[CompoSimmonite]

To run power to my garage I used blue water pipe.

 

[Hopefuldave]

"Stuffing glands" - thick closed-cell foam disc, hole a touch smaller than the SWA, slit from outside to hole - how BT etc. do it in cable ducting.

Dave H. (the other one)

 

[dobbslc]

Just get a length of 40mm duct and bury that. Its water proof and will allow the removal of the cable years later if it fails.
I'd say its almost impossible to seal it up fully, water will always get in the ends somehow.

 

[brightspark]

don't over think it just stick it in the conduit. haven't you ever watched the leccy board or telecom pump out the water in ducts before they start work oh and if you stick it in blue alcathene pipe put electrical warning tape round it other people aren't mind readers

 

[bigegg]

Just get a length of 40mm duct and bury that. Its water proof and will allow the removal of the cable years later if it fails.
I'd say its almost impossible to seal it up fully, water will always get in the ends somehow.

thats basically what i thought.

 

[bigegg]

don't over think it just stick it in the conduit. haven't you ever watched the leccy board or telecom pump out the water in ducts before they start work oh and if you stick it in blue alcathene pipe put electrical warning tape round it other people aren't mind readers

got half a roll of warning tape.
i found it in a trench.