How to get rid of this Bleeding in my baked scene?

[Luis1080]

I need to have the wall in two parts and the lower one also need a surface in the top (in order to hide the upper one and only show the lower one. But when I bake my scene the bleeding between objects appears, as you can see.
Things I have done:

Props have a secondary UV flattern channel for lighting
I have tried unity auto UV mapping for lights and still have bleeding
Light UVs have no overlapping
Vertex are welded between props only
All is perfectly aligned by using a snap
Ligthmap has been baked with high quality
We have launched the lightmap with englithen and progressive lightmappers and both returns the same result

Maybe its normals fault?

[Luis1080]

I solved it myself doing this changes:

The lower part of the wall has now a surface in the top as a separated mesh.
The wall is a single object. But the upper part is hidden using a shader.
We change ligthmapper to Progressive (in ligthnapping Settings)
In Mesh Renderer we use Sitch Seams.

Secondary UV channel has now more padding.
Now ligthmap Padding in ligthmap setting is 40.

An it solves the Bleeding problem.