Saturday, December 16, 2006

More Concrete = Stronger Footings? Not True

More Concrete Does not necessarily mean Stronger Footings.

A post in the ground is only as solid as the ground around it. Concrete holds moisture. Rot needs air and moisture and fuel (sugar) to form. The worst place to have a concrete/wood intersection is at ground level.

Second factor is that when you dig a hole, the top of the hole is normally larger than the base of the hole which causes frost to be able to lift the post (and your fence) out of the ground--dirt washes in beneath the footing and it gets higher every year.
Bell the hole you say? If the bottom of the hole is larger, and the top of the hole is larger, as the frost sets in it will shear the concrete between the two. Don’t underestimate the power of frost.
If you keep the concrete in the bottom half of the hole, frost will set in and anchor the footing in place. Use fine gravel or stone dust to set the post above the concrete footing and it will act as a lubricant and prevent the post from being lifted by frost.

No comments: