Years ago, it was common practice to imbed porch and patio posts in concrete. It was simple: dig a hole, set the post and pour concrete around it.
The idea was to enjoy the added strength provided by the concrete while at the same time creating a barrier between the post and the earth — all in hopes of improving lasting quality.
Whoops, it doesn’t work. Actually, concrete is almost as porous as dirt and it does not prevent the wood it surrounds from being attacked by moisture. In fact, just the opposite is true. A concrete pier is a veritable resting place for moisture — and a nesting place for rot. That’s why porch and patio posts often tend to rot at the very bottom where the wood comes into contact with the concrete.
If you discover that you have this condition, don’t go for the jackhammer. You have a flat — not a blowout.
You have two repair choices and neither one requires concrete removal: you can fully replace the post, or you can trim an inch of the very bottom of the post and repair it using a metal post bracket. In either case, you will need to temporarily brace whatever it is that the post supports — a porch beam, for example.
Measure the distance between the porch and the beam, add a half-inch to your measurement and cut a two-by-four to that length. Next, snugly wedge the two-by-four between the beam and the porch. Don’t try to get the brace perfectly plumb. It was cut too long so it could be “wedged” into place. When snugged up it will be at a slight angle.
Tack the top of the two-by-four support to the porch beam with one or two 16d box nails. For safety, lay another two-by-four on the porch and wedge it between the base of the two-by-four support and something solid like a planter or the front of the house.
A couple of connectors will make either job quick and easy. Keep in mind that you can use either connector for whichever repair you choose. The first hangar is a post base and is a surface-mounted connector. The second one, the column base, is designed to be imbedded in concrete. This is the one you would use if you were to dig out the old post and replace it with concrete.
Now it’s time to determine whether to replace the entire post or just the lowest inch or so. Use a screwdriver to prod the suspect area of the post. Wherever the blade easily penetrates the surface, you can be sure rot exists.
If the rot is confined to the area immediately adjacent to the concrete simply cut off the lowest inch of the post. Here’s how: First, cut the post off at the concrete. Lay a handsaw on its side right on the concrete and cut away. Next, tack the post in place with a couple of nails or screws (you’ll have to toenail here). This will hold the post in place while the second cut is made.
Making the second cut is easy when you use the following technique: Lay a one-inch thick spacer on the porch (a piece of wood, a book, whatever). Lay the side of your handsaw on the spacer using it as a guide to make a perfect second cut that will remove slightly more than one-inch of material between the porch and what is now the new bottom of the post.
At this point the porch post should be literally hanging off the beam about an inch away from the concrete. The hard part is done. All you have to do now is insert a post base bracket and a spacer into the void.
Push the post to the side just enough to mount the bracket over the existing hole. Nail or bolt it in place, insert the one-inch spacer and swing the post into the connector and nail it to the bottom of the post. If the wood in the post hole is completely disintegrated, then dig it out and fill it with concrete. In this situation an “imbedded”-style connector can be placed in the wet concrete patch.
If the rot is excessive and travels up the post, then installing a new post will be necessary. Simply make a single cut into the post at the porch and swing it out to disconnect it from the beam (you may have to first un-nail a bracket at the location where the post meets the beam). Cut a new post to fit and use one of the two previously mentioned mounting procedures.
And that’s all there is to it.
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