Routing new cables under floorboard

[adsmith]

Hi guys after a second option here

In the process of a rewire and I’ve lifted upstairs floorboards on the landings suss out my route for new upstairs ring, lighting and boiler circuits. The joists within the landing have a 25mm hole for existing up and down lighting circuits and no room left. There is a large notch for central heating pipes and also a monster notch for what looks like a gas pipe so I am really reluctant to drill another hole for the new cables as I think already breech the regs on holes and notches in joists. I am able to remove the old cables and replace with new in the existing 25mm hole however will be too tight with added cables. There is however coving in the corners of the downstairs walls and ceiling which leaves a channel under the joist of the upstairs floor. Hope this makes sense. Would it be ok to run the new circuits which don’t fit in the 25mm hole via this void or will this breech the walls and partition section of the regs 7.3.2? Any help is greatly appreciated

Andy

 

[adsmith]

I forgot to mention that the upstairs sockets are fed via a 4mm radial and is also routed via this void section under the downstairs ceiling joists created by the curved coving

 

[telectrix]

all depends on the age of the property and the quality of the joists. houses over 60 years old will have joists that were made from real seasoned wood, not this new kiln dried shyte, that's just about capable of supporting the floor, and will be capable of withstanding another hole, albeit as far as poss. from where plumber has butchered them.

 

[Charlie_]

When you start removing the old wiring won’t there be empty holes for your new wiring?

 

[SparkySy]

That's what he is sayin @Charlie_
He will have the hole but it won't be big enough for the extra circuits!
I have to agree with @telectrix, if it's an old place then the joists will be a descent size and probably if you can find space then that would be the best bet.
I have in the past drilled down the side of the existing hole to make it more of a slot rather than 2 holes too close together.

 

[Deleted member 26818]

There is a prescribed route in the top 150mm of walls.