I am building a small balcony on a flat roof; I have had a galvanised steel frame for this built and installed; I will be attaching wooden decking to this for the floor area.
To do this I will be first attaching 4"x2" joists/battens to the steel frame, and then screwing the decking to those battens.
Question - does the decking need to be raised above the steel frame where it crosses it?
ie Should I fix the 4x2 battens so that the decking will lie directly on top of the steel frame where it crosses it, or should I fix the battens so that the decking will be raised (say 10mm) above the steel frame so there is no contact. ie does it matter if the decking is directly in contact with galvanised steel frame; is that likely to encourage rotting?
To do this I will be first attaching 4"x2" joists/battens to the steel frame, and then screwing the decking to those battens.
Question - does the decking need to be raised above the steel frame where it crosses it?
ie Should I fix the 4x2 battens so that the decking will lie directly on top of the steel frame where it crosses it, or should I fix the battens so that the decking will be raised (say 10mm) above the steel frame so there is no contact. ie does it matter if the decking is directly in contact with galvanised steel frame; is that likely to encourage rotting?