Drilling Into Lintel For Roller Blind

[youdontwanttodoitlikethat]

I want to mount a roller blind in a 6' (1.8m) wide window. To do this I will need to drill upwards into the lintel that spans the window. It's an early 60s house, standard brick faced, cavity and blocks inside. I plan to use red plugs which are 1 1/4" (30mm) long plus a bit extra for the screw.

Is it ok to drill up into a lintel by 35 to 40 mm? Is the concrete likely to be reinforced with steel inside? How deep will this steel be? Will drilling 4 holes weaken the lintel?

Thanks to anyone who has some advice for me. I don't want to drill into the lintel and find it's not a good idea.

 

[^woody^]

It will be fine. Just use the right bit first if it's steel