Trellis Fencing$400 - $2,800 Walkway$700 - $915 Rooftop$800 - $1,200 Deck$1,500 - $2,200 Downspout Trellis A downspout trellis is great for covering unattractive downspouts with beautiful flowering vines. They are great for growing clematis, moon vines, morning glories, and Dutchman’s ...