cables covered in bitumen

[rustynails]

I ran some cables down a wall today and then the builder hacked off a meter up the wall and applied bitumen because of damp which meant the cables got covered in black bitumen. Does anyone think that will affect the cable?

 

[Darkwood]

I have seen roofing bitumen damage pvc cables by causing the platicisers to leech out which compromises the structural integrity of the cable, this was a few years ago but unless you use cables with non migration plasticisers then I assume its still going to be an issue.

 

[rustynails]

I have seen roofing bitumen damage pvc cables by causing the platicisers to leech out which compromises the structural integrity of the cable, this was a few years ago but unless you use cables with non migration plasticisers then I assume its still going to be an issue.

hmmm I have been pondering about it for a few days... I think It would have been better to protect it somehow. they have also had a coat of sand and cement thrown on top...not sure what type or make of bitumen.

 

[Marvo]

I've never seen cables damaged by bitumen and nowadays it's highly likely it's some kinda plastic compound being used and not actually bitumen as such. Bitumen is generally heated before it's applied.

 

[gavin.sibley]

Currently working on a bitumen plant and we have too protect all cables from exposure, but having said that it's more from the heat than anything else, suppose it depends on what temperature it was applied at? The stuff we work with is 180 degrees plus

 

[Darkwood]

Taken from a General Electric PDF

Plasticiser migration from PVC cables when used in contact with polymeric insulating materials is apotential problem. Plasticisers are used in PVC to give the required physical properties such as flexibilityand toughness.These compounds are commonly used in TPS (Tough Plastic Sheathed) Power cables, Cat5 & Cat6data cables and B20 and B95 data cables.Plasticisers are typically non volatile, high boiling point liquids which are absorbed into the PVC matrix atelevated temperatures during the compounding process. Plasticisers are not chemically bonded to the PVCcompound and under certain conditions can be extracted from the compound.Commonly used PVC plasticisers tend to exhibit solubility in polystyrene and polyurethane insulating materials, As a result of this there will be migration of plasticiser from the PVC compound where there is adirect contact between the two materials, this causes the PVC on the cable to become harder and morebrittle. There is also potential for plasticiser migration into bituminised building paper, causing the bitumento soften and flow.General Cable also manufactures TPS cables which utilise a PVC compound containing a non migratoryplasticiser, this will not migrate from the PVC when in contact with polystyrene or polyurethane insulating materials.

The hi-lighted part is what I found in a ceiling where along the length of a cable run against a bitumen base the bitumen had softened dripped and the cables had hardened - The cable was installed after the bitumen was done, this issue was only found where cables were run and in contact with the bitumen, as I said I cannot say the make-up of pvc or the bitumen has altered over the years to avoid this and this was about a decade ago but I would be researching deeper maybe even contacting the cable manufacturers themselves and putting it to them.