Hi, I am building a small extension on top of an existing kitchen (flat GRP roof) and have been advised by the structural engineer that I should increase joists from 6 x 2 to 7 x 2 (span is 4m).
The question is: do I need to remove the existing joists or can i just place new joists in the center of the gaps between the existing joists? (pic nba22 d shows the roof opened up).
The kitchen ceiling is fixed to the existing joists so not removing the existing joists would avoid damaging the ceiling.
And a second question to the same area ( see pic nba22 e ) - i need to build on top of the parapet wall but there is a conservatory nest to it. Am I able to just remove the coping and internal side flashing and build block/block above?
The question is: do I need to remove the existing joists or can i just place new joists in the center of the gaps between the existing joists? (pic nba22 d shows the roof opened up).
The kitchen ceiling is fixed to the existing joists so not removing the existing joists would avoid damaging the ceiling.
And a second question to the same area ( see pic nba22 e ) - i need to build on top of the parapet wall but there is a conservatory nest to it. Am I able to just remove the coping and internal side flashing and build block/block above?