How to Build a Screened Deck Extension

Extending the Deck Surface

• One way to build a screened deck extension is to add to the square footage of an existing deck, then install a cover and screened walls. Extending the deck means you'll need to remove the existing rim joist and construct a new rim. Floor joists and new deck flooring may require additional posts for support. These posts can be made much taller than the deck and its railing so that they form the corners of a frame for screen walls. You'll need to pour concrete footings so the posts are stable and can support the added weight.

New Deck Sections

• Another option for extending a screened deck is to build an entirely new section of the deck. This section may be at a different level, attached to the existing deck with stairs or a walkway. The new portion can be built with large, tall corner posts to accommodate removable screens or a permanent roof that offers a place to attach screens. This strategy allows you to keep your existing deck for open air use.

Extending Screens

• If you have a deck that isn't screened in, you may only want to extend screens to enclose the deck without actually altering the deck's structure at all. The easiest way extend screens to an existing deck is by mounting a wooden or metal frame to the deck rails and corner posts. A vinyl trap will supply the cover for the deck, while sections of screen affixed to the frame with ties will provide the walls.

Planning

• Before extending a screened deck, inspect your existing deck structure to make sure it is in good repair and can handle the weight of an extension, added frame or permanent roof. A replacement may be a better idea than an extension if your deck is old or in disrepair. Most deck building or expansion projects will require building permits. Zoning laws may limit how close your deck extension can be to a property line. Depending on your local building codes, the process of adding screens without altering the size of a deck may not require a building permit, making it potentially the simplest solution.