http://www.steamcommunity.com/sharedfiles/filedetails?id=72496037

I have many grates in my mod as I'm developing some puzzles around that element which I consider a good puzzle element with great potential... The best solution is as followed (in hammer ofc):

• Make a nodraw textured brush 1 unit thick, texture front and back sides only with the grate texture, and tie it to a func_brush / with solidity set to "never solid"
• Make another brush 1 unit thick textured with the trigger texture (same size than above one) and tie it to a func_clip_vphysics; place it right in front of the first brush (it's recommendable to leave 1 unit thick space inbetween both).
• Make a player_clip textured brush 1 unit thick and same size as above 2 brushes (to avoid the player can pass through) and place it right in front of the other 2 brushes (again, it's recommendable to leave 1 unit thick space inbetween both).

This will avoid that bug.

Important: this grate will not behave exactly the same as usual ones in this way: this one WILL ALLOW the funnel to go through while the "normal" grate stops it! please be noted.

josepezdj wrote:
As chicken said in your workshop/steam thread, grates are buggy and I don't know why Valve didn't take some MINUTES to solve that.

I think a similar bug can be found but using the Hard Light Bridge instead. Not only does the cube go through, you can go through as well!