South Side Retaining Wall

Saturday, Jan. 25, 2014
Last weekend I poured the concrete for a footing that would form the base of a channel along the south side of the basin.

Today I removed the form.  This turned out to be quite easy.

The main motivation for the footing was to provide a stable foundation for a mini retaining wall, which is needed to prevent dirt from sloughing off into the channel when it is opened to permit the deck sections to be opened.

I decided to use concrete board for the retaining wall, and attach it to the footing with Tapcons.  I had two sheets of concrete board available, which I had bought for the other side of the basin but decided not to use there.  I had already sliced the 3' by 5' sheets into halves, each 18 inches wide and five feet long.  In order to attach them to the footing, I had to dig out a trench beside the footing, wide enough that I could use a drill to make holes for the Tapcons.

Sunday, Jan, 26, 2013
I cut one of the 18 inch wide slices of concrete board down to four feet, giving a total of 14 feet from that piece plus two whole slices.  Getting the concrete board slices aligned with the top of the deck was not difficult.  I used a combination of dirt and wood shims to hold up the slices at exactly the right height.

But there was an embarrassing mistake.  Despite my following the old craftsman's adage, "Measure twice, cut once", the wall turned out to be about six inches short.

I still don't know how this could have happened.  I was being very careful with the measurements.  But it did.  I had to cut and add a six inch wide slice at the end.  Extra work that shouldn't have been necessary.  Plus it made the wall just a little bit less solid.