Repairing Tapered Columns
Our 90-year-old bungalow has tapered wood columns in front that hold up the roof over our enclosed porch. One of the columns seems to be deteriorating, but I don't know how to repair it or what materials to use. Do you have any suggestions?
—Kevin & Judy Weinstock, Barron, WIsc.
Tom Silva replies: With columns that old, I'd say you're lucky that only one of them has problems. It should be taken care of fairly soon, too, because the more water that gets past those tapered boards, the worse things will be for the interior post, which I suspect is what actually holds up your roof.
First, carefully remove the column's outside boards so you can use them as patterns to make replacements. Then check the post and make sure it's in good shape. If you have any doubts about its strength, replace it with preservative-treated stock of the same size.
I'd rebuild the sides of the column using medium-density overlay, an exterior-grade plywood covered with resin-impregnated paper. MDO is durable, stands up to wet weather, holds paint well, and doesn't crack or check the way most plywoods will when left outside.