How to drill horizontally into a roof corner of concrete house?

[DIYpowered]

Hi, i am a DIY'er and there are electric wires that i want to run along the top of the wall near the roof. The walls and roof are concrete. But the problem is that i cannot get a horizontal alignment just below the roof surface when drilling into the wall. The drill size forces me to make an angle when drilling so that when it comes out on the other side of the wall, the opening is closer to the roof. Is there a better way to do this? Do i need some special equipment or technique?

Here is the concrete drill bit that i am using (30cm):


Here is a picture of one of the corner of the house that i already drilled and then passed the wires. It is not as good as i want it to be - the wires entrance into the wall should be closer to the corner and the roof surface.

 

[Wayners]

I think that's the best you can do.
Often wires are in conduit or trunking. Trunking would hide the fact you can't get in the corner

 

[DIYpowered]

I think that's the best you can do.
Often wires are in conduit or trunking. Trunking would hide the fact you can't get in the corner

I asked a friend and he suggested using a longer drill bit to get closer to the corner. But i am not sure if they actually sell longer than 30cm concrete drill bit? Maybe some extension?

 

[Wayners]

Screwfix sell a drill bit 1m long

 

[Harry Bloomfield]

I asked a friend and he suggested using a longer drill bit to get closer to the corner. But i am not sure if they actually sell longer than 30cm concrete drill bit? Maybe some extension?

I have a set of 1m long ones.. The longer the drill bit, the nearer the corner you can get, but the more unwieldy it becomes.

 

[cdbe]

I have a set of 1m long ones.. The longer the drill bit, the nearer the corner you can get, but the more unwieldy it becomes.

My 1m one is quite bendy and the front half would easily go through square right in the corner.