Sealing off holes made for cables

[Whitling2k]

Morning all!

Quick question - but I'm just returning my ring main to it's rightful place - but in a new stud wall (no new/alterations in wiring, just old cables in a rebuilt wall & floor...)

I've drilled through my footplate and floor into my sub-floor space and worked my cables through - but would quite like to seal the hole off to stop mice finding their way through.

What would you recommend using? Would there be any impact on the rating of the cable? (it's 2.5mm T&E)

Cheers

whitling2k

 

[PrenticeBoyofDerry]

A Silicon sealant will do fine.

 

[ericmark]

Should use fire stop but I would use silicon sealant in most cases.

 

[DaftPunk]

Mice will chew their way through just about anything apart from wire wool.

 

[ericmark]

On a railway job got told off for stripping cable with teeth as cable impregnated with arsenic to try and combat rodent attack. They will eat normal cables so if there is a rodent problem should use special cables.

When wiring on a ship we used a special gland as cables went through walls but hardly required with a house. With telephone exchanges we used fire stop but the stuff was quite nasty so would not really recommend for home use.

For the odd visitor silicon sealant will be fine.

 

[Whitling2k]

cool!

My fear with wirewool is it just rusting away over time - our sub-floor floods annually with the local water table - not a problem and nothing we can realistically do about it - just need to remember to affix all junction boxes!!!

Those little sheets of patterned stainless the DIY shops sell are just too expensive IMO.

I'm hopeful that it's just for the odd visitor - would be quite nice to keep them out of the stud walls and all that lovely warm rockwool!

Chewing arsenic spiked cables? Sounds nasty, but does give me an idea to control the local tomcat population

whitling2k

 

[bernardgreen]

Floods annually with the local water table - not a problem and nothing we can realistically do about it - just need to remember to affix all junction boxes!!!

Floods ? Then NO junction boxes under the floor, even if the boards can be lifted for access.

All fittings should be above expected worst case flood level. That includes sockets

 

[ericmark]

When working with stainless steel if you use any non stainless stuff to clean then it will still rust. So you can buy stainless steel wire brushes and wire wool to clean with so it will not contaminate the stainless steel. Clearly that would not rust.

But the covering on cable is nearly the same as silicon sealant so if they can chew the sealant they can also chew the cables.

 

[ericmark]

Junction boxes should be filled with something like this Re-enterable Electrical Insulating Resin one can't seal boxes very well but if already full then no where for water to fill.

Any gas which includes air will expand with heat and contract with cold so when hot air escapes and when it cools it will suck in anything to replace it. So cold water on a warm junction box will always be sucked in. Even filling the box with petroleum jelly will stop most of the water ingress problem.

 

[Whitling2k]

Seems to have gone off topic a bit! There's no chance of floods affecting the property, it's timber or electrics - 40+ years with the street still standing is proof of that! It does pose some challenges with insects - but nothing that can't be controlled with treated timbers and manufactured sheets.

Thanks for the tips - but in that sense - the electrics are well and truly safe!

I'll look out for some stainless wire wool - I could do with something like that for another gap I need to plug! I had assumed all wire wool would be the cheapest steel available.

Whitling2k

 

[bernardgreen]

Stainless steel scouring pads from the local supermarket may be an economic way to obtain small quantities of stainless steel wool

our sub-floor floods annually with the local water table

so discussion of flood is partly on topic.

 

[JohnW2]

FWIW, my experiences of rodents and cables are that one really "can't win" - so the only real solution is to try to exclude them! If they see a cable disappearing into a piece of wood, even if the gap around the cable is well sealed, they seem to get the idea that there could be potential route through the wood - so if there's no gap around the cable for them to 'work on', they simply start nibbling away at the visible parts of the cable! IME, close to where a cable passes through a joist is easily the most common place to find rodent damage to cables.

Kind Regards, John

 

[PrenticeBoyofDerry]

What about having a cat standing guard at cable entry points?

 

[JohnW2]

What about having a cat standing guard at cable entry points?

That's close to the 'exclusion' approach I mentioned! Mind you, the last cat we had appeared to be frightened of most rodents, so it's not foolproof

Kind Regards, John