DIY: Wooden Porch

Lay out your porch based on the door opening that leads into it, which will determine the height. Mark the width on the sides of the house and drive stakes in the ground with twine stretched between them to mark the outside edges. Square the outline by using a tape measure to measure the distance between diagonal corners and adjusting the outer stakes until the diagonal distances are identical.

Remove any house siding or trim to expose the wall sheathing under the door sill. Locate rim joists or wall plates to secure one end of the porch. Cut a 2-by-6-inch or 2-by-8-inch ledger board to the width of the porch, and nail it in place temporarily with 16d framing nails and a hammer. Use a level to make sure you set it level, and place it far enough below the bottom of the entry door frame to allow for flooring, which typically is 3/4 inch thick.

Set pre-cast concrete piers with corner joist brackets in the top at the outer corners. Place piers between those corners and the house if the porch is deeper than 16 feet. Dig holes with a post-hole digger at least 24 inches deep, or below the frost line, which is the depth to which groundwater in soil freezes. Set the piers in the holes with a bed of gravel, and make them level with the house, allowing a slope of at least 1/4 inch per foot from house to corners. Fill the hole with dirt or concrete to secure the piers.

Mark spots on the ledger board to attach it to house framing, and drill pilot holes with a power drill and 3/8-inch bit through the ledger into the framing. Fasten the ledger with 1/2-inch lag bolts, which have a screw point and a bolt head. Drive these with a ratchet wrench at least 1 1/2 inches into the framing. Put washers under the bolt heads to allow some drainage.

Fasten 2-by-6-inch rim joists to the ledger with metal joist hangers and to the corner posts with galvanized screws in the holes of the pier bracelets. Use a level to set rim joists with the 1/4-inch slope. Put an outer band across the outside between the rim joists, to make a frame the width and depth of the porch.

Measure 24-inch spaces along either the width or depth of the porch on the rim joists, depending on how you want the finished floor boards to lie. Run finished flooring either the same direction as the house wall or perpendicular to it. Install hangers for 2-by-4-inch joists, cut boards to fit and nail them in place across the frame. Use 8d galvanized nails to fasten hangers to rim joints. Set 2-by-4-inch boards into the slots and fasten them with nails through the holes in the hangers.

Finish the floor with flooring boards, planks laid side by side or tongue and groove flooring. Nail planks to the floor joists through the face of the plank. Nail tongue and groove through the tongue of one board, then slide the groove over it and nail through the next tongue. Rip the outside board on a tongue and groove floor with a table saw to make a smooth outer edge.