Can I pass an electric wire under the flooring boards?

pieroabcd

Hi,
I need to add a couple of wall outlet on the other side of the bedroom.
Can I pass an electric wire under the flooring boards? Is it safe and compliant with the regulations?

Thanks

FreeBear

If the cable needs to pass through a joist, you should drill a suitable sized hole (12-15mm) on the centreline. See this page for notes on where to drill or notch - https://www.labc.co.uk/news/how-get-it-right-notches-holes-solid-timber-joists

You can notch the top of the joist (not recommended) and fit a steel plate over the top to reduce the risk of a nail or screw piercing the cable - If you do this, mark on top of the board where the cables are.

ThisIsWeird

If ground floor, see if you can clip the cable to the undersides of the joists - easy and safely out of the way.
If between floors, as FB says.

pieroabcd

It's at the first floor.
I've found a 2cm gap between two flooring boards running along the short dimension. I wouldn't even need to dent the joists.
In a plastic conduit it seems to be the right place.

ThisIsWeird

pieroabcd said:

It's at the first floor.
I've found a 2cm gap between two flooring boards running along the short dimension. I wouldn't even need to dent the joists.
In a plastic conduit it seems to be the right place.

So the cable will be run immediately below the floorboards?

pieroabcd

ThisIsWeird said:

pieroabcd said:

It's at the first floor.
I've found a 2cm gap between two flooring boards running along the short dimension. I wouldn't even need to dent the joists.
In a plastic conduit it seems to be the right place.

So the cable will be run immediately below the floorboards?

That is the plan if it's a valid solution 

ThisIsWeird

pieroabcd said:

ThisIsWeird said:

pieroabcd said:

It's at the first floor.
I've found a 2cm gap between two flooring boards running along the short dimension. I wouldn't even need to dent the joists.
In a plastic conduit it seems to be the right place.

So the cable will be run immediately below the floorboards?

That is the plan if it's a valid solution 

Tbh, I don't know.

grumbler

pieroabcd said:

ThisIsWeird said:

pieroabcd said:

It's at the first floor.
I've found a 2cm gap between two flooring boards running along the short dimension. I wouldn't even need to dent the joists.
In a plastic conduit it seems to be the right place.

So the cable will be run immediately below the floorboards?

That is the plan if it's a valid solution 

BELOW or BETWEEN?

pieroabcd

grumbler said:

pieroabcd said:

ThisIsWeird said:

pieroabcd said:

It's at the first floor.
I've found a 2cm gap between two flooring boards running along the short dimension. I wouldn't even need to dent the joists.
In a plastic conduit it seems to be the right place.

So the cable will be run immediately below the floorboards?

That is the plan if it's a valid solution 

BELOW or BETWEEN?

It's both :-)
Below the superficial flooring boards (laminate/engineered/bamboo) that you walk on but between the rough flooring planks (pinewood/whatever) that are nailed to the joists.

the_lunatic_is_in_my_head

As FreeBear says you are best going through the centre of the joist in the appropriate zone depending upon the span of the joist, this can worked out using the table in the link FB provided.

If the space between the joists is too tight to get the drill into you can buy an attachment to get in tight spaces such as this:

https://www.amazon.co.uk/DeWalt-DEWDT71517T-Torsion-Attachment-Yellow/dp/B00ORMG6AA 

Personally I wouldn't want to run live wiring in-between the two floor coverings, I can't see it would be compliant at all, can't comment on whether it would be safe.  

ThisIsWeird

Piero, you'll be glad - you will feel a lot better - if you go to the small extra effort of lifting a 'board, and drilling through the joist centres. 

If there is that large a gap between the old floorboards, then the awkward bit of the job - extricating the tongue&grooves - shouldn't be an issue.

Relax knowing it's a job well done.

What are your walls made of? If solid (plastered block or brick), when you come to the walls, cut the cable channel down to the top of the skirting board from where the backboxes will be, and then use anything suitable - large screwdrivers, drills, chisels - to bore down behind the skirting board to what will hopefully be a gap between the solid wall. Use a Hoover to suck the debris away. Very good chance you'll be able to run a cable behind the skirting without having to remove it. Yes, it'll be immediately behind a 'board again, but the difference is that folk will know it's likely to be there :-)