Besides what the others said, a frame of 2by4 lumber every 2 or 3 or 4 foot. 2' makes a stronger frame. Use the dark synthetic to help keep the sun out. With the 4' stuff, you can also roll it horizontally and wrap it around the entire porch with the one seam in the middle as opposed to making a series of 4' by 8' screens.. The wall will be about 8' tall anyway. You'll have a top and bottom plate to staple the screen to. Use some 1by2 material to cover everything on the outside. A day job for a handyman.