How to Replace Structural Columns on a Front Entry

Measure the length of your existing column from the point that it intersects both the porch and ceiling of the porch.

Place a 4-by-4-inch post vertically on top of a light-duty hydraulic jack and slowly raise the beam to the point that it will stay in place by buttressing it up against the underneath of the porch roof or the porch ceiling. Place the jack about 1 foot away from the existing column and to the inside part of the porch. Repeat the process on the other side of the porch with a second 4-by-4 post and jack.

Raise the columns resting on each jack until they raise the roof of the porch by about 1/4 to 1/2 inch. Ideally, the old column and the ceiling begins to separate in the process.

Cut the existing columns at both the top and bottom using a reciprocating saw. Cut as closely as you can to the ceiling and the floor, but be careful not to cut into either. You may have to use a small pry bar to pull away any of the residual materials that you are unable to cut.

Sand down the surfaces where the old column connected to the porch and the floor. Use a hand planer if necessary to ensure that the surface is as flat as possible.

Cut your new column with a miter saw or jigsaw. Use the measurement that you initially took at the beginning of your tear down and replacement process, but subtract 2 to 4 inches based on the thickness of the top and bottom squares that you will attach to the column. If the columns you are replace are square, you can choose a piece of lumber that matches the dimensions of the columns. Otherwise, you may need to use a wood lathe to round the columns if that is what you prefer.

Cut two square pieces of wood that are larger than the diameter of the replacement column. These will serve as the top and bottom of your column support structure. Wood that is 1 or 2 inches thick should suffice for this task.

Glue and nail the squares to both ends of the replacement column with 3-inch galvanized steel nails. Ensure that the measurement of your column and its additions match up with your initial measurement of the first column.

Place glue on the top and bottom of the column structure and lift each of the columns into place where the old columns were located. Slowly lower each of the hydraulic jacks back onto the new columns.

Drive wood screws or nails through the top and bottom squares to complete the attachment of the columns to the porch and the roof structure.