The flat top of the RSJ is supporting the floor (and the wall) above. It's an I beam and I was thinking of using the lower lip of the bottom of the I to support the ceiling joists. Sorry if it's not too clear without pics, I'll try and get some.
Thanks for the replies by the way.
A previous owner of my ground floor flat removed an internal wall between two rooms and replaced it with an RSJ directly supporting the joists above.
I am planning to install a false ceiling to cut down on the noise from my upstairs neighbour.
It seems feasible to me to rest one end of...