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 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 your support posts are to be painted, I fill the crack
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.