how to extreme

Build a Screened Porch

Construction How-To, Decks, Outdoor Living, Porches and Gazebos June 28, 2003 Sonia










Ahhhh, the romance of a screened porch—lemonade and cool comfort for those hot summer days and a hammock or chaise lounge for slumbering those warm nights away. And it’s all outside where you can still enjoy Mother Nature without the hassle of insects. A screened porch not only can add to the enjoyment of your home, but to the value as well. A screened porch can also be constructed in three phases. Many homeowners have started with a patio, added a roof and then ended up screening a porch. The porch shown is a prime example of building in phases over a period of time. Or the project can be done as a single phase from beginning to end. (For a low maintenance product for your porch, check out Latitudes Decking Products, click here.)






Whether adding an enclosure to a roofed area, or building from start, in many instances you will be required to provide a building plan for any home addition to local building authorities. You may also be required to obtain a building permit.

Regardless, the first step is to create a solid base for the construction of the porch. In some instances decks may be used. In this case the area of the deck with the porch must be floored over with a solid material to keep the insects from coming up through the cracks in the deck. Additional support must also be placed under the deck to support the additional weight of the porch, as well as any snow that may accumulate in northern climates. In many instances, however, the porch will be constructed on a concrete or other type of solid patio. The ideal scenario is to pour a concrete slab for the porch, which can then be further embellished with a slate or quarry tile floor. A screened porch will have to handle the elements, so make sure all materials used are for exterior use.

If using a poured concrete slab, or other solid surface, make sure there is proper drainage of water away from the house, as water will get into the porch during storms. Most builders consider 1/4-inch slope per foot the proper design for a concrete patio. For a 12-foot porch this would be 3 inches, and this is too much for a porch constructed on a slab. For the porch shown, a pitch of 1 inch for the 12-foot length was used. This doesn’t hamper construction quite as much as the sharper pitch, but still allows water drainage.

The slab must be laid out and formed. If you do not have the proper tools or experience with concrete work, you may wish to have a contractor do this portion. Pouring a slab of the size shown is do-able for many Extreme How-Toers, if time is taken in laying out the project so it is square and formed to the proper pitch. Concrete tools can be rented at many rental stores. Do not attempt, however, to mix the concrete for this project. You will need to purchase bulk concrete.

Make sure the slab is well reinforced and a footing is poured around the edge. The footing should be sized to match your geological location. Check with local concrete dealers as to the size and depth required. After forming but before pouring, place a layer of gravel down, followed by welded wire reinforcing. Pour the concrete, level it off with a drag and trowel it smooth. You can hand-trowel, but a power trowel speeds the work. If building a screened porch on a new slab, place anchor bolts around the perimeter in locations for the bottom plate of the porch. The plates can then be bolted to the slab to anchor the porch in place. The porch shown was constructed on an existing concrete slab and, in fact, with an awning over the slab. The structure was simply framed and screened. In this case the lower plates were anchored in place with a rented concrete gun that shoots anchors through the plates into the concrete.