I'm interested how professional installers hide the cable feeding contacts on patio and french doors. It's obviously possible to completely hide the cable without the use of trunking - though I can't decide how.

Do you drill upwards through the lintel and hope your aim is good enough that the hole pops out under the floor upstairs?

On a related note, how do you go about drilling behind PIRs? Presumably a very long 6mm or 8mm drill and use the flexibility to keep the chuck away from the wall? Any ideas where I can buy such a drill - Screwfix and similar only sell 300mm max.

PIRS behind coving and fish out through flooring with a 20mm hole if not floorboards.

I usually got down to doors by drilling up inbetween the lintel and plasterboard, being careful not to pop out half way up the wall. Usually it worked out and you'd pop out upstairs. You'd have a bit of cable showing within the door reveal though.

You'd have a bit of cable showing within the door reveal though.

That's what I'm trying to avoid. Previously I tried drilling between the wall and the plasterboard - but forgot about the galvanised bead that covers the corner. Drilling straight through the lintel at an angel seems like the tidiest solution - but that's b#%stard hard concrete.

The bit of cable showing just chase it in, only needs a 5mm drill bit running along the angle. Slot the cable in, fill and paint.

I agree with Timmo, although I would tend to remove a piece of floorboard upstairs directly above the intended drop and gauge the possibility of running down behind the cove as a starting point. Sometimes though, a bit of revealed cable is impossible to hide..are you really going to notice a 'teeny weeny' bit in say a month's time ?

Drill very carefully and steadily straight up between the brick and plaster, then drill horizontal between the brick and plaster under the lintel, that just leaves a couple of small holes to fill. If it's papered then wet and slice a small strip back. Coving as above mentioned, lift a board if you can and have a look around before carefull drilling with a 400mm x 5mm bit up.

This is a skill new engineers are loosing with wireless becoming more popular.

It depends what the constructions is, if possible I would drill up through the lintel and aim for the void above, this leaves no holes to fill.

Alternatively, Plan B, useful for drylined walls is as norm, leaving a couple of holes to fill or cover with something.

Then Plan C would be chase and fill, I have an old 4.5mm HSS bit I use for that, 8 core fits in this slot very snug.

I have a long 6mm drill for "Plan B" that slots through the holes in the galv edging strip, if you aim right.

The 'Main' skill if you asked me !!.