Put a roof over your head
On a nice, breezy day, you might not think much about having a cover over your porch or deck. But when the sun is beating down or heavy rain is pouring, a roof offers welcome protection. Building a roof over your front or back porch or deck is easier than you think. Use this step-by-step guide to learn how to build a porch roof from start to finish.
Whether you’re planning a roof for your backyard deck or want to know how to build a front porch roof, consider the following items while planning your project.
Porch roof construction requires using power tools and climbing on ladders. Only use this type of equipment if you are comfortable doing so, and always use extreme caution. Touch up on important ladder safety tips. You should also use protective gloves during this roof-building process.
The pitch of a roof, also known as the rise and run, is a roof’s slope or angle. Before building a porch roof, decide how you want the roof to be angled. The minimum roof pitch recommended for a shingle roof is a 2:12 slope. In other words, for every 2-inches the roof rises in height, it runs 12-inches in length.
If your porch roof will connect directly to your home’s existing roof—which is most often the case with single-story homes—choose a pitch that is slightly flatter than your existing roof. If your porch roof connects to the side of your home—which is most often the case with two-story homes—use the same pitch as your existing roof for consistency.
Building a roof over your porch almost always requires a building permit. Contact your local permitting office to confirm whether or not you need a building permit and to get the process started. Roof-related building permits cost between $250 and $500 in most cases.
Use these steps to build a roof over your deck or porch for that much-needed shade or protection from the rain.
The rafter plate, also called the ledger board, is a 2-by-6 board that attaches to the structural framing on your house. It should span the entire length of the porch roof. Your porch roof framing then attaches to the rafter plate.
Start by marking the location for your rafter plate. The top edge of the rafter plate will be the highest point of your porch roof framing.
Make sure the top edge is at least 3 inches below any windows to allow enough clearance for roofing shingles.
Consider the desired ceiling height of your porch roof and the rise and run of the roof. pitch. Snap a chalk line at the top of the rafter plate based on these measurements.
Measure down 6 inches from the top line and snap another line for the bottom of the rafter plate.
Carefully remove the siding and sheathing from your house where the rafter plate will be installed.
Cut a 2-by-6 board the length of your porch roof.
Drill pilot holes into the roof—this will help with installation.
Attach the board to the rafter plate location with lag screws.
You should install support posts on the side furthest from your house to hold up the other end of the patio cover. Place support posts or columns on each end of your deck and every 6 to 10 feet in between. Include a support post on each side of an opening for stairs. The posts can be 4-by-4 up to 8-by-8, depending on your preference.
Once you have chosen support post locations, dig a hole at least 18 inches deep into the ground. If you live in a cold climate, it's best to dig your holes below the frost line—check with your local building department.
Fill each hole with about 4 inches of gravel, then place the post in.
Use a level to make sure the post is plumb.
Pour bag mix concrete into each hole around the post and allow the concrete to fully cure before proceeding.
Cut the tops of the support posts down to the roof’s final ceiling height and so the roof will have the correct pitch.
Next, notch out the top of the support posts to fit the header beam. The header beam stretches across every support post. Along with the rafter plate, it supports all of the rafters that run along the porch roof. The notch should perfectly fit a 2-by-10 header beam.
Using a circular saw and a manual saw, cut a notch into the top of the support columns that is 1 1/2 inches wide and 9 1/2 inches deep.
Place the 2-by-10 header beam into the notches on the support posts.
Drill pilot holes to ease the installation.
Attach the header beam to the posts with lag screws and washers directly through the notches.
Moving back to the rafter plate, attach rafter hangers on the plate every 16 inches as well as one on each end of the deck.
Install 2-by-6 rafter boards angled from the rafter hangers to the header beam at each hanger location and secure into place. Install nails into the rafter hanger holes and toenail the rafters into the header beam.
With all of the rafters in place, you can begin to install the porch roofing.
Start by nailing down 1/2-inch exterior plywood across the entire surface of the roof framing.
Install your asphalt shingles, metal roofing, or any other type of roofing material you prefer.
To prevent water from sneaking in between your house and porch roof, install drip flashing. To do this, you should nail a strip of drip flashing between the roofing and the side of the house. The flashing should run on top of the roofing shingles. Drip flashing helps in preventing roof leaks that could cause water damage.
Finally, you should reinstall siding on top of the drip flashing and on any other exposed parts of your home’s exterior.
When deciding whether to build a roof yourself or hire a pro, it all comes down to your carpentry skills. While you will save some money on labor and only have to purchase materials if you build the roof yourself, it might not turn out how you expected. Poorly constructed roofs won’t last long, can leak, and likely won’t pass a building inspection in the first place.
If you don’t quite have the carpentry chops to build a roof, there is no shame in hiring a pro. A professional carpenter in your area will charge anywhere from $3,000 to $10,000 for the cost to build a porch roof. Hiring a professional ensures your porch roof is constructed safely and will last for years to come.
