jjc001 wrote:
I have read most of the messages regarding drilling into concrete
lintels above a window and saw the recommended various tools (SDS
drill etc) but one post has a comment stating that this can weaken
the lintel and cause structural damage.

I'd like a definitive answer myself. A few thoughs however;

There must be a million drilled lintels happily holding up both walls &
curtain rods - I've done it myself many times without any visible problem.

I would guess that a lintel is designed with a huge safety factor included -
in other words, if it's sold as being able to hold a ton it will probably
hold two ton.

Thinking about it, would a hole actually weaken a lintel anyway? What are
the physics?

I've also done a Google search on 'drilling concrete lintels' and found
several sites (inc Wickes) that give advice on how do do so and none has any
kind of warning about weakening the lintel - if it was a common problem
surely there would be something out there somewhere?

I'd be happy to keep doing it.

Dave