Building a Cantilever Balcony

[lexie]

Hi Guys

I want to build a Cantilever Balcony coming out of my 1st Floor Bedroom. I had this extension put on 5 years ago and just wish I had then had this work carried out.
Is it possible to attach 10x3 Treated Joists to the existing Joists within the property, and bolt together securely, leaving approx 4ft overhang for the Cantilever Balcony the main question is CAN I use Treated wood or will I be best off using Metal RSJs instead of the Wood. Just worried about the wood becoming wet and transferring onto the internal Joists.
I understand for every foot I come out I need 2 foot on the inside.
Thanks for your help guys

Jimmy the Sparkie

PS did have this posted on the Architect/Building project page, but never got any response. :(