Good morning forum, I am currently constructing a bay structure to an existing dwelling (3 storeys high). Building Control have requested the steel beams to the inner leaf (traditional wall construction) have fire protection of 60 minutes fire resistance to comply with element of structure in Part B. My proposal is to encase the steel beams (inner leaf) with 2 layers of plasterboard (to achieve 60 mins) to the internal face of the internal wall/window head. I don’t see no problem with this but is there an issue where the top of the timber window (not fire rated) meets the underside of the beam plate? Any feedback would be great, cheers.