How to Fix a Rotted Porch Pillar

Purchase at least two beams of 4-inch by 4-inch lumber: one to support the weight of the porch and the other to be the actual pillar replacement. Alternatively, purchase one 4-inch by 4-inch lumber beam and a pre-cut, rounded porch pillar from a lumberyard or home improvement store.

With the assistance of a helper, erect one 4-inch by 4-inch lumber beam about 3 feet away from the rotting porch pillar, wedging it in vertically between the porch deck and roof.

Hammer a few nails diagonally through the beam into the porch roof, a process commonly called "toenailing." Do the same at the bottom of the beam, nailing into the porch deck. This will support the weight of the roof while you replace the rotted pillar.

Put on goggles and a dust mask. Cut the rotted pillar out with a circular saw, sawing near the bottom and top, leaving only a few inches attached to the roof and deck.

Pry away the remaining stumps from the deck and roof using a pry bar. Pull out any nails still in the roof or deck with a nail puller.

Set another 4-inch by 4-inch lumber beam or pre-cut, rounded pillar into place where the rotted pillar stood. Fasten to the roof and deck with a hammer and stainless steel nails.

Treat the new pillar with a coat of wood sealer using a paintbrush and let dry overnight.

Remove the 4-inch by 4-inch lumber support post by pulling out the nails with a nail puller.