New Build-outdoor lights

[driverman]

OK, I'm installing a couple of outside wall lights to the front of new build house. The lights are to be installed either side of front door. Protruding outwards at 90 degrees to the house either side of the front door area are 2 x thick cavity brick walls (not covered like a porch) . The thick walls are face brick work both sides. The walls are each approx. 2m long. Wall lights are to be sited half way, in other words about 1m from the house. From inside the house I need to get a cable to each wall light position. Cables will drop down from ceiling in hallway approx 1 m, then go horizontally through house cavity wall ( as if wall light was other side) towards the protruding face brickwork walls.
Hope above all makes sense. Internally I will ensure cable is run within a safe zones. ie light switch below 1 x wall light cable run and a socket will be sited under the other light cable run. As new build, I don't want to surface clipped cables on face brickwork. In this particular case as walls are outside could I go via cavity (horizontally) possibly in pvc conduit.I know it's not allowed now by today's standards within the house. Would another way be to carefully drill horizontally within the face brickwork to wall light point?
Hoping of course that the drill doesn't wander and mess up the face brickwork.

 

[telectrix]

can you not chase the cable in the mortar then repoint.? obviously keeping a horizontal line from outside lights.

 

[driverman]

can you not chase the cable in the mortar then repoint.? obviously keeping a horizontal line from outside lights.

Yes, could do I suppose.Thinking about it, I've done that in the past on stone walls. Would that be acceptable and comply?

 

[Rockingit]

TBH, I think I'd just be tempted to use a stranded cable suitable for exterior, like H07, and run them through the cavity. I'm assuming it's just structural and no insulation involved.

 

[driverman]

TBH, I think I'd just be tempted to use a stranded cable suitable for exterior, like H07, and run them through the cavity. I'm assuming it's just structural and no insulation involved.

Mainly structural yes. I reckon I did see thermal insulation in the walls also at the very top before the roof was put on. I would also be being going a short distance horizontally internally as well.

 

[driverman]

You know years ago in this particular situation, I wouldn't of battered an eye-lid installing said cables in a cavity. How things change and make you think a little bit deeper. But this problem has now presented itself, so got to deal with it best I can.

 

[Rockingit]

Well you could de-rate 1.5mm H07 by around 400% and still be nowhere near the load of one lamp.

 

[jaypp]

Mainly structural yes. I reckon I did see thermal insulation in the walls also at the very top before the roof was put on. I would also be being going a short distance horizontally internally as well.

Am a little confused. Do the walls have a roof on 'like a porch' as it sounded like they didn't in first post? If no roof, maybe drill up at an angle and conduit on top. If has a roof, I'm with you on horizontal at an acute angle, although it sounds like with the distance, you'd have to drill into cavity (Never do this!!!) from inside and test your fishing skills!! Are conduit drops out of the question?

 

[driverman]

Well you could de-rate 1.5mm H07 by around 400% and still be nowhere near the load of one lamp.

Are you saying that if 1.5mm HO-7 cables used in thermal insulation it will be OK? I'm more concerned about it being in the cavity itself really.

 

[driverman]

Am a little confused. Do the walls have a roof on 'like a porch' as it sounded like they didn't in first post? If no roof, maybe drill up at an angle and conduit on top. If has a roof, I'm with you on horizontal at an acute angle, although it sounds like with the distance, you'd have to drill into cavity (Never do this!!!) from inside and test your fishing skills!! Are conduit drops out of the question?

I had a feeling this might be a bit difficult to explain. Oblong building, front door in middle with glass panels either side. Overall distance glass door and panels approx.6m. Above door and glass panels is all glass up to the soffit board height. Either side of glass panels 2 x walls protrude outwards approx 2m to form if you like an entrance but all exposed to the elements. At the very top an apex roof has been put on to tie with the main roof. Yes insulation has been installed but really wasn't necessary, as both sides of the wall are exposed to the elements, hence both sides face brickwork. Phew , hope that makes sense. I'll try to take pic and upload if time at weekend. My fishing skills aren't too bad tbh.

 

[DPG]

Get a photo up. Daz

 

[driverman]

Get a photo up. Daz

Yep will try over weekend.........Well high tec stuff and me don't go together!

 

[Richard Burns]

In conduit, in cavity, I think.

 

[driverman]

In conduit, in cavity, I think.

I think that is the only option available really. It's the best option of the bunch. Would that comply with BS7671? As it is a new build I don't want any deviations from the regs. I was under the impression that on a new build no deviations were allowed but I think I read on another thread that was not the case.

 

[Richard Burns]

Deviations from the regulations are only applicable where the change is safer than the regulations require.
Non compliance with the regulations is not permitted at any time.
A cable run in conduit is a permitted installation practice for BS7671.smile5
Running a cable in the cavity of a wall is not recommended by building regulations as it may bridge the gap (huh), however if the cable is run in conduit parallel against one wall then this would prevent the bridging scenario as it is held in place and so I believe it would be compliant with the requirements (?recommendations) of the building regulations.