Front porches are one way to extend your living space outside your door and invite your neighbors in. Porch columns are typically structural supports, holding up the porch roof and railings. As such, any damage that happens needs to be repaired as soon as possible to prevent further decay or structural damage to the rest of the house. Three common types of porch column fixes are: repairing rotted wood, fixing splits or cracks and complete replacement of the column itself. When replacing a column, remember to use a post the same strength or stronger than the original.
Inspect your column for rotted wood with an awl. Probe the damaged areas; if the awl penetrates more than 1/8 inch into the wood easily, rot is probably present, or will be setting in soon. Rot happens most often at the tops and bottoms of columns where water pools.
Remove the rotted wood by prying away any rotted trim. Use a sharp wood chisel to gouge out any other rotted wood so that the rot does not spread to surrounding wood, or draw pests, such as bores and termites. Scrape down to solid wood, or use a handheld rotary tool to grind the soft material away. Rot that goes deeper than one fifth of the column's thickness requires replacing the column.
Fill the void with auto body filler. Mix the putty with hardener according to label directions and fill the area with a flexible putty knife, smoothing it over to the same profile as the surrounding column. Allow the putty to dry, and sand the putty and surrounding surface smooth using a oscillating tool.
Replace any trim or molding and nail it in place with finish nails. Paint or stain the repaired area to match the rest of the column.
Inject exterior waterproof wood glue into cracks in the column with a large syringe until the crack is filled to slightly overflowing.
Wrap strap-style ratcheting clamps around the column just above and just below the damaged area and tighten them to close the crack until the glue seeps out. Close the crack completely if possible. Wipe excess glue away with a damp rag.
Leave the clamps in place overnight, then remove them and sand the area with an oscillating tool. Paint or stain the repair to match the column.
Use a 4-by-4 post on screw-type jacks, one on each side of the column, to slowly raise the porch roof until the weight lifts away from the column.
Knock the column out from under the overhead beam with a sledge hammer, gently.
Measure the space and cut your replacement column to length to fill the void. Fit the top and bottom trim onto the new column and slide it into place. Let the jacks down and remove the support posts.
Tips & Warnings
- Always wear safety goggles when sanding with an oscillating tool.
Things You'll Need:
- Pry bar
- Wood chisel
- Handheld rotary tool
- Body filler
- Putty knife
- Oscillating tool
- Paint or stain
- Replacement trim
- Waterproof wood glue
- Strap clamps
- Screw type jacks
- 4-by-4 posts
- Replacement column
- “Exterior Wood Columns”; John Leeke; 1991
- “Wood Joists, Beams and Columns For Farm Structures”; Robert A. Aldrich; 1961
- Spectis Molders: Column Installation
- Jack Hollingsworth/Photodisc/Getty Images