Hello all

I have a small question about replacing mortar in an old brick wall
(about 100 years old). The wall in question is a 2 wythe load bearing
wall that used to be the exterior of the house, but ~50 years ago an
extension was built. As a result, the wall is now an interior wall.

When exposing the wall (it's in good enough shape to keep as an
exposed brick wall), I noticed that there is a section of missing
brick about 1 sq ft (clearly intentional). There are also a couple
loose mortar joints, etc.

To my question: I'm looking to mortar in a couple of bricks and
repoint some of the joints. I've heard that for extremely old brick
type O mortar should be used. However, this is a load-bearing wall
that won't encounter any weathering issues - should I use type N
instead?

I'm not worried about color matching, the patched area is not going to
be one of the exposed areas. I am concerned about load, as I am going
to be cutting a doorway into the brick wall and putting a header in,
so the patched areas will experience somewhat increased load.

Any advice out there?

Thanks

Paul