I created a bridge just using stairs and the roof tile which does have walkable checked. When i tested it out in game i didnt walk across it but instead fell down to the ground after walking up the steps and then walked with my head clipping the bridge/roof tiles.

Am i missing something?

It sounds like the navigation paths might not be configured correctly for the tiles. If I understand correctly, it would look something like this, where the walking paths go up the stairs and across the bridge. According to how the tiles are defined, it may not end up like this automatically when placing them in the Map Editor, but using the Connect mode you should be able to add/remove paths as necessary. Hopefully this helps!

Thanks for your reply, yeah the was a gap from the stairs to bridge for the walkable green nodes on each side that should fix the problem.