Hi,
I was thinking of removing a built-up square in the basement next to the chimney (see picture).
When I started chiseling, I discovered an old channel that was probably used for the oil burner once upon a time.
If I remove the entire square (which is outside the chimney base), it will create a hole into the chimney base as illustrated in the sketch on the photo. The hole will be about 10-20cm deep and about 60 high (angled toward the corner).
Is it alright to remove this and then brick it up and plaster over, or could this cause issues like cracks or shifting?
The entire chimney base is about 70*80cm.
I'm not used to jobs like this
Grateful for answers from someone who has experience with this.