Crumbling Braces and Post

With the hot summer I discovered that the V-groove wheels of my roll-off roof were riding up on the angle iron rails that had warped somewhat in the heat. While inspecting the rail system, I discovered that the braces and a large part of the middle post had rotted away under the paint! The wood just literally crumbled away when grabbed by hand. Apparently, the water was captured in that V and was going behind the braces.