How to Add a Gable Roof to Your Front Porch

Lead Image
  • 16-24 hours
  • Advanced
  • 2,000-3,500
What You'll Need
Miter saw
Framing square
Ladder or scaffolding
Tape measure
Manual or electric nail or staple gun
Roof trusses, custom ordered and engineered
Asphalt shingles
Plywood sheathing
15-pound roofing felt
Roofing tacks
Galvanized nails

Add curb appeal and value to your home with the addition of a gable roof to your front porch. A gable roof protects you from snow, rain and excessive heat. It also provides you with a living space suitable for outdoor entertaining or relaxing.

To make this type of modification to your home, you will need to use building plans, obtain a building permit and receive a final inspection once you have completed the building process. Here are the steps you will have to undertake to add a gable roof to your porch.

Step 1 - Position the Porch Truss

Position and secure the gable porch truss flat against the top plate of the porch's end. Secure the truss that is closest to the house first with nails on both sides. Extend a cord or line on the level from the truss's peak to the roof line's highest peak. Start nailing the ridge board to the gable roof.

Step 2 - Set the Valley Rafters

Measure and cut the valley rafters based on your building plans. Begin with the ridge board at the roof's downward tip to the porch truss and set the valley rafter. Going down to the valley rafter, fasten the vertical jack rafters to the ridge board. Nail each on center. The spacing will depend on your area's local building codes.

Step 3 - Install the Sheathing

Determine the width of the sheathing used on your home’s existing roof and follow the same installation on your porch's gable roof. Generally, this will be around 5/8-inch thick. Measure the sheathing before you install it and deck the roof by nailing the sheathing into the roof trusses. Put the sheet ends at the center points on the roof truss rafters. Adjacent sheets will use the same nailing area or surface.

Step 4 - Install the Roofing Felt

Going from left to right, roll out the roofing felt. Start the first run from the bottom and attach it with roofing tacks. Overlie every run by 5 or 6-inches. Finish it off by adding metal flashing on the roof’s valleys, as well as on the lowest edges to prevent water damage and leaks.

Step 5 - Install Shingles

Add shingles to your gable roof that match your existing shingles. Begin at the bottom and work your way up. Paint the wood or siding to match or complement your home’s colors. A nail gun or staple gun can easily fasten the shingles to your roof; however, if you live somewhere with strong winds, you will want to opt for a nail gun.