Department of Environmental Design

Wood porches are beautiful, but sometimes boards or planks break or splinter, making them unsafe. Using the following instructions, they can be repaired.

What You will need

  • Portable circular saw
  • Crosscut saw and wooden miter box (or crosscut saw set into a steel miter box)
  • Framing square (blade that is 24 inches long)
  • Wood chisel (blade at least 2 inches wide)
  • Heavy-duty pry bar
  • Replacement flooring (type, kind, and thickness to match existing flooring)
  • Nails


The following procedures are based on tongue-and-groove flooring laid on a subfloor.

  • Examine the damaged boards and decide how much flooring must be removed.
  • The porch flooring will commonly have tongue-and-groove and be laid on a sheathing subfloor. Determine this before you begin.
  • Laying a tongue-and-groove flooring on a subfloorMark the area to be repaired, using the square and a pencil (Figure 1). This mark should be approximately 1/2 inch from the crack to avoid hitting the nails (blind-nailed) with the saw blades (Figure 2). Carefully adjust the blade of the portable saw to the thickness of the flooring to avoid cutting the subflooring. Place the saw at the center of the end mark, slightly tilted, with the blade resting on the flooring (Figure 3). Make the cut to the corner of the marked area. Cut the opposite end the same way.
  • Laying a tongue-and-groove flooring on a subfloorMake the side cuts of the marked area in a similar manner. To assist in guiding the saw, nail a strip of wood next to the pencil mark. You may now slide the saw along the edge of the strip as you make the cut (Figure 4).
  • Using the hammer and chisel, finish the cuts down to the subfloor (Figure 5). Using the pry bar, and a small block for leverage, lift out the boards to be removed (Figure 6).
  • Laying a tongue-and-groove flooring on a subfloorAt each side of the opening are the wood strips you left in order to miss the nails in the flooring. Using the hammer and chisel, remove these strips, making sure not to damage the tongue of the good board, as shown in Figure 7.
  • Using the nail set, sink the nailheads that now protrude at each side of the opening (Figure 8). The area is now clear for placing the new flooring. The flooring will be supported by and attached directly to the subfloor joists. The following procedures should be used for porch flooring without a subfloor: In steps 3 and 4 above, the end marks and end cuts must be made at the center of the joist width so that the flooring (both new and remaining flooring) can be properly supported, as in Figure 9.
  • The best method of locating the joists is to tap the flooring with a hammer until you hear a "solid" sound indicating a joist underneath.
  • After you have located the joists, proceed with step 3 above. When you make the cut, be careful not to cut the tops of the floor joists. Remove the damaged pieces from the ends with a pry bar (step 5).

Removing square-edge flooring

If the flooring is of the square-edge type rather than tongue-and-groove, the boards need be marked and cut only at the ends. After the ends are cut, take the hammer and nail set and drive the nails completely through the boards of the area to be removed. Now apply the pry bar at one end of the cut boards, being careful not to damage the boards that are to remain.

Replacing the damaged flooring

  • Laying a tongue-and-groove flooring on a subfloorMeasure the length of the cut-out opening of the floor. As illustrated in Figure 10, use the square to mark this cut line on the new board.
  • Place the board in the miter box with the hand saw placed at the 90 degree miter (Figure 11). Make the cut just slightly to the outside of the cut line.
  • Lay the board in the opening. Blind-nail it in place by driving the nails diagonally just above the tongue of the board (Figure 12). Complete the nailing with the nail set. Space the nails the same distance they were spaced in the existing flooring.
  • Final board with tongue removedPlace the remaining boards in a similar manner until you get to the final board to be replaced. The final board must have the tongue removed (Figure 13). You will now face-nail this last strip and countersink the nails. Fill the nail holes with wood filler and wipe away the excess with a cloth soaked with solvent. Finish the surface of the new flooring to match the rest of the floor.

Your benefits

The bounce and shakiness is removed from your porch; it is safer to walk on; and you can prevent later, more costly repairs.

The guide was reprinted from the United States Department of Agriculture publication, Program Aid number 1193, Extension Service.
Publication No. GH5933