The object on Layer 8 ("Planks") is not rendering, although it is totally visible in Viewport.
If I select all the layers together (the desired outcome), then hit Render, all the layers will render except this one. If I move the object to one of the other layers, it will still not render.
"Camera" is selected in "Ray visibility" of the Object panel.
When I go back and forth between objects to compare the Object panel of the problematic object with the others, I see no difference.
"Duplication" is not enabled in the Object panel.
In the Outliner, all three icons for display in Viewport, Select and Render are selected for the object.
I had the same problem a few months back, which was never really resolved because I couldn't share the file because of size issues (same here).
Here are the Render Layers settings - there doesn't seem to be a difference from one of the layer in the scene to another:
I tried to render with two different versions of Blender and found the same problem.