Damage to armoured cable - repair ?

Rick Hughes · 2008-05-21T20:01:25+00:00

I have 3 core SWA armoured cables under my drive, and then popping up and entering the base of my entrance pillars - providing feeds to lights.These were buried deep, pea gravel & warning tapes .. Etc.While my drive was being prepared for paviors - I pointed out several times to contractors where they would be, and while deep across drive do not dig within 4" of base of pillar - I'd do that by hand.I cleaned around to show where they come vertically up and then enter pillars . today when deciding to scrape around the borders ready for start of edging they ignored all . and have now taken a small chunk out of the top of the pvc sheath exposing the armour wires on one cable.aprox 5mm wide x 10mm long, exposing armour wires in centre of damage.I know ideally cables should have entered through foundations rather than across first brick course - but it is where it is.I am not relying on the armour wires for earth .. so no worries there, but anybody know a practical way of repair ?The contractors say simply to ignore - as long as not cut through there is no problem . !Next week it will be under the pavior drive so not exposed .. but would prefer to prevent water entry and possible future problems.Options ?- multiple layers of pvc tape ?- Is there any liquid resin I can pour over the whole cable to encase the damage?- Self-Amalgamating tape?- In case in concrete ?- or should I just ignore as contractors advise.The damage is within 10mm of the wall, and unless I want to demolish the pillar . I can't get the cable out .. I can probably pull it back 50 mm or so effect a repair, but not enough room to cut & joint.No point in suggesting I ask them to put it right, they would just bury and continue.

May 21, 2008 26 Replies

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The Wanderer 18 years ago

I assume the armouring has been bonded.....

They would say that, wouldn't they?

That's unlikely to keep out the moisture. Seen too many fit for purpose but incorrectly applied u/g cable joints that have gone bang coz a jointer failed to prepare everything properly. You'd need to clean and roughen the surface of the pvc *and* most importantly degrease with carbon tetra chloride to have any chance of success.

I'd suggest Denso tape, let one of the contractors get his hands good and messy applying it! Insist, however, that they do it with you in attendance, and to your satisfaction. The cable should be wiped clean and the surface pvc roughened all around with a wire scratch brush or coarse emery cloth. If you don't, moisture will work it's way along the smooth surface of the pvc. Make sure the underside is cleaned and prepared properly!

You may be faced with that one day.

Tell them you will withhold payment unless the repair is carried out to your satisfaction. A roll of denso tape will only set them back a couple of quid. As I said, tell them you insist on being present when the work is done, and it must be to your satisfaction.

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ARWadworth 18 years ago

How about the rubber sleeve of an armoured gland pack that is sliced open longways, placed around the damaged part and then taped into position whilst the jointing compound set.

Adam

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js.b1 18 years ago

SWA enters pillar at 90-degrees above ground and rises up inside the pillar. ... is the brick pillar hollow? ... does the cable exit the pillar to the lights?

(hindsight - run swa in pillars thro smooth bore flexible conduit, Twinwall).

... can you instead pull the cable from the light end, draw a rope & new swa in? If yes then fit a suitable ip junction box, 2 cw glands (can be buried if u/g pratley jn).

... can you sds the mortar with armeg brick chisel to remove a brick from the pillar? If yes then do same, higher cable entry provides more pillar side cable to work with.

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Andy Hall 18 years ago

I missed that specific point about proximity to wall. In that case, no, the plastic shell arrangement wouldn't be suitable, but the resin remains a good way to make a fix.

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Andy Hall 18 years ago

I'd missed the point about the joint being so close to the wall.

Using resin would still be good, perhaps with some other container.

If this is all below ground, could you carefully remove a bit of brick from the wall to expose more cable on that side? Not to the extent to put in a shell, but perhaps another 20mm or so to give 30 and thus space for some other kind of mould.

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