Underfloor wiring

Muahahaha

Starting a renovation soon and installing a new floor was just wondering about the possibility of running wires underfloor for two things. First is Id like to have a socket in the floor with a flip up lid, socket would be approx 1.5m from a wall where there is an existing socket. Anyone know what the minimum depth is of a box for floor sockets?

Second is how to connect up a projector & speakers on one side of the room with a satellite box/games console on the other. AFAIK running wires through the ceiling is not an option because of joists going in the wrong direction. But also Im pretty sure the floor underneath is concrete on top of which would go the underlay and then the new floor. I wont know for certian till the old floor comes up but would a concrete floor mean its just not possible to wire underneath because of space? And if it were possible what is needed, some type of metal conduit ducting? Are there regs for this type of wiring, I wont be doing the work myself but just want to know how it should work so it is safe.

Stoner

There is flush and under screed trunking, unittunk make it

Or else tubed in metal 20mm or 25mm conduit

Roadtoad

I really think a socket 1.5m out will look like crap to everyone except yourself. It's very office like, on a suspended floor and usually under a desk or similar.
Planning on tiles, carpet, timber? What about water spillage or cleaning?
I'd look for another way to get power to whatever you are planning for.

You can drill joists. Hole in the centre (half way up) and as small as serves the purpose.

salmocab

Roadtoad wrote: »

I really think a socket 1.5m out will look like crap to everyone except yourself. It's very office like, on a suspended floor and usually under a desk or similar.
Planning on tiles, carpet, timber? What about water spillage or cleaning?
I'd look for another way to get power to whatever you are planning for.

You can drill joists. Hole in the centre (half way up) and as small as serves the purpose.

If its under a piece of furniture its unlikely to be seen by anyone which is generally where they go.
I was always told to drill 2/3 of the way up to keep the strength in the joists as the lower the hole the weaker the joists gets

Muahahaha

Roadtoad wrote: »

I really think a socket 1.5m out will look like crap to everyone except yourself. It's very office like, on a suspended floor and usually under a desk or similar.
Planning on tiles, carpet, timber? What about water spillage or cleaning?
I'd look for another way to get power to whatever you are planning for.

You can drill joists. Hole in the centre (half way up) and as small as serves the purpose.

The socket itself will be just slightly under a sofa with legs and mainly out of sight- the problem I have is Im currently using 2m cables to power the laptop/phone and the cat loves to jump up and swing from them. I can be sitting there some nights engaging in a tug of war with the cat over the laptop cable !

Regards drilling joists, I thought it possible but very intrusive, i.e. the sparks would have to open up a hole in the ceiling to get access every single joist? Or do they do it from above by removing carpet & floor boards and going in that way?

My preference would be to do it under the floor (as its coming up anyway) between the concrete and the laminate/underlay. But Im just unsure if this is workable and safe. Concern is over time is with people walking on laminate sitting on top of the wire it will get frayed/split causing bigger issues. Condensation/coldness of concrete floor in the winter also a concern. I also dont know if there would be enough space, stoner mentioned 25mm which Im thinking might just get crushed between the laminate and concrete floor?

2011

The concrete floor would have to be chased to accommodate the conduit. It would not be advisable to “squash” the conduit between the concrete and the laminate floor. There is a bit of work in it but it is worth it.

Edit: Needless to say it would be best to install the cables in the conduit before fitting the floor

Stoner

2011 wrote:

Edit: Needless to say it would be best to install the cables in the conduit before fitting the floor

True

I couldn't see a 20mm conduit being squashed could you?

I've never seen a conduit being squashed.
Personally I wouldn't have an issue with the conduit being fixed to the concrete floor, with a floor sitting on top of it. I'd imagine it would hold its shape longer than the floor.

Muahahaha

Thanks for clearing that up lads, I didnt know how strong conduit is so thought it could become dangerous over time with people walking over the floor. I'll chat to the sparks about chasing the concrete floor as that sounds like the perfect solution.

Just out of interest- I'm guessing another way of getting wires from one side of a room to another side unseen is to put them behind the skirting boards. But presume this is against regs and not safe? Are there minimum distances that wires must be hidden away from easy access?

2011

Muahahaha wrote: »

Thanks for clearing that up lads, I didnt know how strong conduit is so thought it could become dangerous over time with people walking over the floor.

The conduit will be 20 or 25mm wide. As the floor is concrete and the chase will only be marginally wider than the conduit it will not be supporting the floor. Now that I think about it if the floor is raised perhaps it will be possible to avoid the chase, it will depend on how it is done. A steel conduit will not get crushed very easily (as Stoner said), however you would want to ensure that it will not interfere with the floor by pushing it up.

Just out of interest- I'm guessing another way of getting wires from one side of a room to another side unseen is to put them behind the skirting boards. But presume this is against regs and not safe?

Yes, it would be against the regulations unless you use skirting trunking. This would look out of place in anywhere other than an office in my opinion.

Edit:Personally I wouldn't have an issue running speaker or HDMI cables behind a skirting board as it is not dangerous. However I would not do this with a mains voltage cable as this would present an unacceptable risk.

Muahahaha

Ok finally onto this and having spoken with the workmen we've decided not to chase the concrete floor but to instead go behind the walls and around the room. The plasterboard is coming down for insulation to be installed anyway so it makes sense to do it this way now.

So Im just looking for any tips on the actual cabling with future proofing it in mind. What Ive got is tv & Sky box on one side of the room and then a projector, games console & speakers are going the other side of the room. I was thinking of putting in 2 x HDMI cables and 2 x speaker cables with the idea being if a cable ever fails for some reason that there will be a back up. Is there anything else I should be thinking of cable wise, I haventgot a 4k tv but sure I will at some stage in the future- are HDMI cables different for 4k? Also anyone know if modern projectors can receive a signal and play content via wifi or is running a cable from laptop to the unit still the only way?