Exposing a lintel

[Linto]

As part of my lift conversion I, well the SE, need to examine an existing lintel to check that it's up to the job of supporting part of the new floor.

The house has been extended in the past (late 90s) so the lintel is part of the original  exterior wall and is now an interior double door.

So what's the best way of doing this? Just go at it with my hammer drill with a chisel bit or something a bit more refined? 

Where about on the span should I expose it?  on part of the span or at an end? Which side, underneath or does it not matter?

Any advice you could give would be appreciated.

Linto

 

[Mr Punter]

I think you are best asking the engineer.  Try not to damage any surfaces that will remain.

[Linto]

Good point, but he's on holiday for a week now and I was hoping to get it done over the weekend.

All I need to do is remove the plaster covering it, I think, but I don't want to take off more than I have too as my patching skills are considerably less than my making a mess ones.