Many decks are elevated well above grade, exposing you to the view of your neighbours. While that may be fine in many cases, you may not want to be on display every time you use your deck. A privacy screen is essentially a decorative fence attached to your deck to provide privacy from your neighbours. Because a privacy screen may be replacing a railing on higher decks it must be constructed to the same standards as a railing to provide safety, as well as privacy. (Check local building codes for specific requirements when installing privacy screens also being used as guard rails)
Privacy screen posts are installed the same way as rail posts, with each of them set inside the outside joist and/or faceplate. Match the space from the bottom 2X4 framing member to the top of the deck surface the same space as the railing horizontal bottom space. Install the top 2X4 at the finished height of the privacy screens less the thickness of the finished top rail. Privacy screens are often trimmed in with routered 1X2 trim around the perimeter to give it a more finished, professional look.
Below are a number of different options for privacy screen construction with privacy screen plans, drawings and design tips.