In the past, the base of the log posts were the first things to rot. The end grain soaked up moisture where they stood on the wet floor when it rained. To protect the end grain from moisture, we set the posts on plates of pressure treated 5/4 board before we lowered the the roof structure onto them.
It was a challenge to get the posts plumb, aligned directly over the support beams below and exactly centered over the treated plate. Jeffrey held a 4 foot level against the log as Sue adjusted the plate. On the ladder, Dave kept the temporary support post from falling on us while Scott, Ken and Al turned the jack to lower the roof onto the log.
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