Custom Concrete Texture Not Working
I made a less dingy texture for the floor and ceiling to match the style of portal 2, the ceiling is fine, but the floor has some sort of overlay that is automatically applied to it, where is this file located in the gcf and what is it called?
I have a feeling thats a detail texture and I think you may have to check the .vmt file. I can't remember the name and location but world editor will tell you in the texture browser. its got "mod" in it somewhere (use that in filter to find the concrete textures).
Am I right in assuming that you've replaced/overidden the old diffuse texture map with your one?
EDIT: You'll have to extract the .vmt, makes changes and place it into .../portal/materials (sry if you already knew this)
I looked, so where are the detail overlays? I can't seem to find them for some reason... 
You don't need to change the actual texture to get rid of those cracks. Just use GCFScape to extract the file "concrete/concrete_modular_floor001a.vmt" and place it in the correct directory, just as you did for the texture VTF file. Then edit this file with Notepad or whatever, and remove any lines referring to $detail, $detailscale, $detailblendfactor and $detailblendmode. This will remove any references to the detail texture.
(Be sure to distribute the VMT file with your map.)
Other Portal 2 maps: Medusa Glare
Portal 1 maps: Try Anything Twice | Manic Mechanic
Thanks, it worked, but by the way, it's not for a map, I'll be releasing a Portal 2 based texture pack in replacement of the dingy looking Portal textures, I'm not very good with mapping 
But metal doesn't crack...
since when?