Cracking of Posts : Tim Copeland Construction

Why?

The 6x6 used to support your deck is quite massive, 2.5 times more mass than a 4x4, which is adaquate in for the actual load in most cases. But the pressure of the wood from the inside affects the outermost areas of the wood due to the circular grain pattern that a tree takes when growing. Usually just one side will crack and release the pressure on the other three sides.

What I do about it:

When unpainted, I select the best edges and face them towards the highest traffic flow area.
I order extra posts and extra length to be able to select the best and return or discard the rest.