How to Replace an Upper Level Porch

Remove railings and any wood flooring, using a pry bar to loosen nails and a hammer or crow bar to pull them. Strip the porch to the roofing or waterproofing under it. Inspect the roof for any leaks, rot or weakness. Take off the roofing of the first-floor porch if it is deteriorated and inspect the underlying decking; replace any bad decking with new plywood or oriented strand board.

Use a level to make sure there is some slope to the porch, at least an inch every 10 feet away from the house, preferably more. Put down tapered foam board insulation if necessary to add a slope. Install new roofing membrane, if necessary; use thermoplastic olefin or a polyvinyl product, which can be fastened with an adhesive. Overlap membrane at seams.

Put metal flashing on all edges of the porch, fastened over the roofing membrane with shingle nails. Add flashing between the porch and house wall if there is none or if it is not solid; remove a strip of house siding if necessary to flash this area, then replace the siding.

Install porch flooring, preferably a tongue-and-groove style which will secure joints between planks. Cut a groove off one plank with a table saw to start, then add planks across the roof. Lay flooring parallel to the house wall or perpendicular. Saw the tongue off the last plank to fit the porch floor. Fasten flooring to roof decking, at roof joist locations, with galvanized nails long enough to penetrate into the joists. Finish the floor with facing or edging boards around the outside.

Put posts against the house wall, on both outside corners and at 8-foot increments between those points. Set posts in metal post brackets, fastened to the floor with the posts set upright in them. Use a level to get posts plumb and fasten them in the brackets with galvanized nails.

Build a railing; fabricate the railing with horizontal top and bottom rails and spindles or balusters in between, on the porch floor, then set it in place between posts. Make a railing as basic or ornate as you wish; some railings are simple rails and spindles, others use squares, rectangles or diamonds instead of vertical spindles. There are often regulations concerning the height of railings, so be sure to check your local building code.

Secure the railing to the posts with galvanized nails, typically toenailed, driven diagonally with a hammer through the rails into the posts. Cover the post brackets at the bottom with trim boards. Cut 1-by-4-inch boards with 45-degree miters, for instance, and frame the posts with them to cover the brackets.