Porch Roof Construction
Use Framing Techniques to Match the Home's Pitch and Shingle Color
Mar 26, 2008
Many homes have a front porch but no roof to protect it from the elements and add to its usefulness. This is unfortunate, because porches should be enjoyed despite in all seasons. In addition, screening it in will protect the home's occupants from predatory bugs.
Roof lay out and framing are not the most basic project abilities to pick up, but with a rudimentary grasp of woodworking and the right materials and tools, building a new porch roof is a weekend project.
Porch Roof Basics
A new porch roof add-on should look right; in other words, it should look as if it belongs. What does this mean? For one thing, it should maintain the same pitch as the home’s roof. Also, the shingles should match the home's roof as closely as possible. The end-game is both functionality and protecting home equity.
How complex is the home's existing roof? This may affect how this project will be designed.
How extreme is the roofing overhang on the home? 14" to 17" is not uncommon. Measure it and plan to make the porch roof overhang match it.
Basic Tools Required:
- Set of sawhorses
- Tape measure
- Circular saw or miter saw
- Framing square
- Ladder or scaffold
- Hammer or roofing nail gun
The Porch Roof Layout
The home’s configuration will determine the starting point, but in general these are the steps to follow. First, set the end or gable porch truss flush against the porch’s end wall's top plate. Now, start working the way back towards the house. Set the roof trusses as they're encountered and brace them together.
When the truss closest to the house is secured in place, pull a mason's line back from its peak up to the roof line peak. This is where to nail the ridge board to the roof.
Set a valley rafter on both sides. Start at the ridge board at the home's roof’s point down to the porch truss. Secure jack rafters now. Make them perpendicular to the ridge board down to the valley rafter. The local building code will determine the spacing. By most codes, they will be on 16" or 24" centers.
Many roof designs call for an overhang on the gable end to protect the end wall from the elements. Again, duplicate the home's overhang. As mentioned above, 14" to 17" inches is likely.
Weather It In
Finally, complete the roof with normal roof finishing techniques. Install the sheathing. Now roll out felt from left to right. Make the first run at the bottom and overlap each run by about six inches.
Add metal flashing in the roof’s valleys and right along the roof’s lowest edges. This is to safeguard against rain runoff. Now, nail on the shingles. Like the felt, start at the bottom and work up.
Use an exterior grade paint or stain on any wood columns, fascia boards, etc., to conform to the home's architectural theme.
