Building a screened in porch
There are multiple ways to build a beautiful porch.
Here is one of mine...
Before starting a project like this it is a good idea to check with local officials and departments to verify if any permits are needed for your area. You want to make sure you don't cover any under ground utilities. You also don't want to dig into any under ground utilities. Safety should always be first.
Determine the size porch you want for your intended use. Remember, the bigger you go the more money it will cost.
Keep in mind it doesn't hurt to get some ideas from a professional before you tackle your own project.
Mark out your deck location with string to determine your corners. Make sure it is square.
Dig a whole in each corner and approx. 4-6 feet apart on the outer wall. Make them equally spaced. This porch is 14 ft. wide so I used 4 footings for my support posts. I feel the more support the better, but don't go over board with it. Each footing needs to be dug to a certain depth depending on your geographical location and local codes. Basically you want to make sure you are below the frost line so you don't end up with any frost heeves (warping). The inner wall is lagged to the house frame. The floor joist are 16 in. on center and doubled on all four sides to prevent warping and give it added strength to support the walls and roof.
Add your decking boards. 5/4 inch decking is what I use. There are various types of decking. Pressure treated pine lumber and composite boards are most common. Treated lumber is cheaper but has more upkeep to make it last.
Determine where and how big you want your steps to be.
More Framing. Frame your walls and roof. Lag the roof to the house the same way the deck part of the porch was lagged. Use of metal brackets makes joining boards easier.
Frame the roof, setting the rafters 16 in. on center.
Use plywood for your roof. 1/2 inch thick is sufficient. There is plywood specific to meet roofing needs.
Choose your roofing material. The pitch of the roof may determine the proper material to use. Here I used asphault shingles over tar paper. Metal or rubber sheet are a couple other options.
Add some screen, trim and doors to decorate to your liking. There is aluminum or fiberglass screening. I like to use aluminum.
Enjoy your finished product for years to come.
Keep in mind there are lots of options in materials and design. Visit your local lumber yard/hardware store for help with any questions you may have. The more people you talk to the more you can learn about it, and you always learn as you go.