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Follow up question to Q/A #393

State IA
Description Text We have been allowing the substitution of 6” x 8” posts when replacing older 8” x 8” post installations for a while now (Q/A #393 dated May 2009) but there have recently been discussions about whether the vacated hole needs to be filled and tamped before driving a 6” x 8” post in or whether a 6” x 8” post can be placed in the hole and only the remaining 2” gap be filled and tamped. Our concern is that standard soil strength would be difficult to achieve if only tamping 2”, given the small space in which to work, but it has been requested and we wanted to get your thoughts.

  • Guardrail
Other Keywords none
Date April 24, 2017


We would concur that attempting to reinstall the 6x8 post in the excavated 8x8 hole and fill and compact the remaining 8”x2” space would be difficult to effectively achieve.


As such, we would prefer that the 8x8 hole be backfilled and tamped prior to installing the 6x8 post. This should provide for more consistent post installation and behavior. 

Date April 25, 2017

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