Yes you may be able to use timber to span 5m but then the doubling up of joists or depth can intrude into the useable space.
A SE will give a swift overview of your design, no problem (I am not an engineer by the way!). Try not to use one as part of a package from a "loft company". If you do...
Hi
I need to replace my floor covering which covers the entire ground floor. My house is a 1980's "box" with quarry tiles laid directly onto interlocking boards and which are then nailed to joists.
The layout and issues with dirt prevent laying carpet, but my problem is this.
The floor...
Dont try to do this yourself or rely on others from this forum for such specific engineering advice!!
The best advice anyone can give you, is to talk it through with a structural engineer. The parameters of your design preclude the ability of anyone to give a realistic assessement of how best...