New wiring, reuse existing holes or create new

[unclebob1]

I've currently got my ground floor ceilings down, and am running network/cctv and alarm cables.

There were some redundant power cables (both ends cut off but wire not removed), which i have removed leaving me a set of holes in wooden joists.

Question is, do i reuse these holes or do i make a new set to regs (between 1/4 and 1/3 of the end of joist?)

Common sense would say reuse the existing so as to not weaken the joist with more holes, but when the electrician comes in to rewire lighting in a few weeks, should he reuse or make new?

 

[EFLImpudence]

Yes, reuse the existing holes.

The network cables will have to be sufficiently insulated if in the same hole and next to the electrical cables.

 

[unclebob1]

Thanks EFL, If i reuse the existing, and the sparky uses new then there should be at least half a meter between the two sets so should hopefully be ok, but will note and adjust my cables if they get in his way!

 

[JohnW2]

Question is, do i reuse these holes or do i make a new set to regs (between 1/4 and 1/3 of the end of joist?) ... Common sense would say reuse the existing so as to not weaken the joist with more holes, but when the electrician comes in to rewire lighting in a few weeks, should he reuse or make new?

I agree with EFLI. There may be debates about what the regulations actually 'require', but I think this is one of those situations in which common sense should prevail.

Do I take it that the hoes are sufficiently far from the edge of the joists (so as to be safe from nail penetration etc.)?

Kind Regards, John

 

[unclebob1]

John, most are - its about an 8 inch joist most holes are between 3 and 6 inches (ie in the middle) a few are at the top, along with some notches... I'll use the middle ones only!

 

[JohnW2]

John, most are - its about an 8 inch joist most holes are between 3 and 6 inches (ie in the middle) a few are at the top, along with some notches... I'll use the middle ones only!

Fair enough. If you found yourself having to use any which were 'too close' to the top, you could attach metal 'protector plates' to the top of the joist in the relevant place.

I should perhaps have added that, based on previous discussions here, there seem to be at least some electricians who (despite the 'common sense' to which you have referred) are hesitant to use existing holes which are not compliant with current regs, on the grounds that they might find it hard to defend themselves (or even prove that they hadn't created the holes) should "anything go wrong" (which, of course, is incredibly unlikely).

Kind Regards, John

 

[unclebob1]

I cant get to the tops of the joists at present (im working form under!) and fair point re being non compliant... hence i may as well use the old ones, and let him make the new ones as he needs!

 

[JohnW2]

I cant get to the tops of the joists at present (im working form under!) and fair point re being non compliant... hence i may as well use the old ones, and let him make the new ones as he needs!

Fair enough. However, I have to say that, if it were me, I would want to stick to the 'common sense' and would not want an electrician to be drilling additional 'unnecessary' hole in my joists - so, if an electrician felt compelled to do that (to 'cover his backside'), I would probably look for a different electrician who didn't.

Kind Regards, John

 

[unclebob1]

Thanks for the info, I'll see what he says/does and go from there.

 

[EFLImpudence]

Yes, there are probably some who think that's where the wires must go;

 

[Iggifer]

So long as the hole is within reason, in the centre of the joist, I'll always try and re-use existing holes. It's ridiculous to add more (unnecessarily) and further weaken the joist when there's a useable hole there already.

To anybody looking afterwards (should they choose to) it's patently obvious existing holes have been re-used as the wood is already seasoned through the hole.

 

[JohnW2]

To anybody looking afterwards (should they choose to) it's patently obvious existing holes have been re-used as the wood is already seasoned through the hole.

Indeed - but is seems that there are some who fear that, even if it were obvious that they had used pre-existing holes, they might still be 'culpable' in some way (don't ask me!) if 'something happened' after they had put cables through joists in places which were not reg-compliant (in relation to the structural integrity of the joist) at the time they did it!

Kind Regards, John

 

[Iggifer]

Quite, but the way I see it, is, if they're too close together say, you're only exacerbating the situation by adding more holes.

Not that it really makes a difference the way plumbers go about their holes and notches! Those guys just dgaf. In the last 3 months I have seen plumbers

• Notch the underside of joists for 4" pipe
• Drill 25mm holes basically touching for 22mm pipe
• Drill pipes through the bottom 1/3 of joists
• Chop out an entire leaf of a block wall (hidden by a riser) to access a leaking soil stack - maybe 4 blocks, and then just put the ply back on the riser.
• Run a gas pipe surface in a (new build) flat from boiler to hob because they'd forgotten to get in before boarding.

And then if they can't be bothered with all of that butchery, they just lash their pipes in anywhere and expect the chippy to box them in.

 

[JohnW2]

Quite, but the way I see it, is, if they're too close together say, you're only exacerbating the situation by adding more holes.

Exactly - the way I see it, too. In my house, there are multiple holes and notches all over the place, many in positions which would now be non-compliant - to add yet more, in the name of 'compliance' would, IMO, be crazy (even though it wouldn't matter much in most cases here, since many of them are enormous - many 9" x 3" or even 12" x 3" - they don't build house like wot they used to )

Kind Regards, John

 

[Iggifer]

How d'ya like them timbers?!