In most instances, Perma-Columns will need to meet wind uplift requirements – the ability of your structure to remain attached to the soil profile. There are two ways to achieve this – both methods using the pre-cast hole in the bottom of the Perma-Column.
1. A concrete collar attached by means of either a piece of rebar through the Perma-Column or a bolted on column extender .
2. Uplift anchors bolted to the column with packed fill around posts.
Column extenders are used when deeper post embedment is required and/or greater uplift values are needed. The minimum concrete backfill should reach the point of column extender attachment. This method allows for a combination of foundation pad as well as uplift. Two lengths are available – 12” and 24”. Bolts used in the hardware packages are A325 (grade 5).
See section 9 of the Design and Use Guide for more details.