David I have never seen any fencer lift a gravel board up to head height. The normal procedure in erecting slotted concrete posts and fencing is to position your first post then insert gravel boards and/or fence panel prop as required and then positioning the next post along against the gravel board or panel. I did once see a fence made entirely of posts and concrete panels 2m high but that was constructed by three workers and a FLT.

I got the impression Bert was considering simply to rest gravel boards against his existing slotted posts?

Richard