How to Enlarge a Porch Foundation

Inspect the porch and house foundation for water issues. Check gutters and downspouts -- along with soil drainage and erosion problems.

Remove the existing porch roof and columns, if you're changing the roof shape significantly. Use a pry bar to carefully remove overhangs, roof sheathing and trim, as you might use them on the rebuilt porch.

Build onto the existing framework if you're adding length only to a basic sloping roof. Cut 2-by-4-inch boards for the framework, with a circular saw. Attach the framework to the house and the existing porch roof framing with bolts. Cover the new space with 1/2-inch plywood and add asphalt shingles over the entire roof.

Construct a new base that's perfectly level with the existing porch flooring. Dig footings to hold a wall of concrete blocks, for example. Create a new trench for pouring a concrete footing below ground level with a rented trencher. Dig this trench so the finished footings hold rows of blocks even with the existing block.

Plan to add bricks or stucco, so the new foundation looks perfectly blended with the existing foundation from a curbside view. Remove bricks across the front -- so you can brick the front starting from scratch, with no visible brick seam.

Pour a concrete floor base using a wooden form constructed from 2-by-6-inch boards. Build the framework to hold a new concrete pour, but add metal gridwork before having concrete delivered.

Construct a bigger porch roof over the larger foundation. Bolt the new roofing framework to the house framing securely, keeping in mind safety aspects.

Finish up the foundation covering. Install new brick work to wrap the old and new block foundation. Add stucco or house siding as other options.