covering over the sideway on our end of terrace house

[paulz]

Our side entrance is bordered by a brick wall, and we'd like to cover the bit between the house and this wall. The other side of the wall is pavement - the road I live in - which we're sideways onto, so the pavement runs parallel to our house. if you get my drift. The wall is flat on the outside [pavement side] topped off with concrete coping stones. The run of the path [inside] is about a 12 foot [3.65m] and 5' 9" [1.75m] approx wide.

[1] the side wall has pillars, I'm guessing it's best to pack these out, so that there's a flush run?
[2] looking to collect any rain water that falls on it, so is the easiest way forward to build a sort of gully/ u shaped bit along the side wall and sit the guttering in that?
[3] what sort of fall from [a] the house wall to the side wall should I be aiming at and [b] on the guttering?
[4] we'd like to keep it light and airy so corrugated plastic or twinwall? I'm hoping this is reasonably clear!

[welsh brickie]

I think its best to use an aluminium box gutter for that length you require, and pvc roofbars with polycarb for the roof panels.
You can bolt the box gutter to the pillars,and add gallow brackets for extra strength.The fall can be minimal.