I had a balcony (not external) but brought it into the house as part of extension works. The old balcony sliding doors and external wall that the doors were set into have gone, but the steel lintel that supported both them and one edge of a ceiling/floor remains.
There is a joist sat on the remaining steel lintel (part of the remaining floor/ceiling). The steel lintel is now far more than required to support just a floor/ceiling.
Should the steel lintel be removed (to facilitate a continuous ground floor ceiling without a visible supporting beam), how much would the timber joist sitting on it need beefing up to support the existing flooring (3m) and new flooring that would extend beyond it (2m)? I could just bolt another timber joist to the existing (7.5"x2.5") and sit them both on padstones?